http://www.appliancepartspros.com/radio-study-guides.aspx

The G4NJH SITE which has lots of amateur radio related information.

http://ourworld.compuserve.com/homepages/drcp

The D.R.COMPUTER PRODUCTS site, where information on their range of computer-based amateur radio kits can be obtained.

http://www.logprobe.com

The web site of Carl G Lotstrom, there is quite a lot of useful information, including details of a log probe for use up to 600 MHz and a page of small projects that Carl has documented.

http://www.tonnesoftware.com

Elsie, a pasive filter design program from Jim Tonne, WB6BLD

Internet Treasure Trove article links from VHF Communications 3/2000

SYNERGY

Address: http://www.synergymwave.com

Amazon

Address: http://www.amazon.de

There is also a US store - http://www.amazon.com and an English store – http://www.amazon.co.uk

Focus

Address: http://www.focus-microwaves.com

Digital Signal Processing

http://www.mrccos.com

HAMVIEW and SPECTRAN

NARDA

Address: http://www.nardamicrowave.com/east/support/software.html

MICROMETRICS

Address: http://www.micrometrics.com

TRANSTECH

Address: http://www.trans-techinc.com

Internet Treasure Trove article links from VHF Communications 4/2000

AGILENT

Anyone who has recently been searching the Hewlett-Packard homepage for data sheets, application notes, S-Parameter files or PSPICE models will have been bewildered. These things have suddenly disappeared without trace and no clues to be found as to where they’ve gone!

There is a very simple reason for this, it is currently fashionable to split relatively large companies up into smaller parts and make them into independent entities, naturally with new names!. So we also have to make the corresponding move in this case.

New address: http://www.agilent.com

ANRITSU

Address. http://www.anritsu.com

List of German electronic shops on the INTERNET

ZRS

Address: http://www.hamradio.si/hid.html

Active Filter

Address: http://www.remcom.com

Internet Treasure Trove article links from VHF Communications 1/2001

Ansoft

A change is becoming apparent in the sales philosophy of producers of HF and microwave CAD software. Up until now, free test versions have been on offer which either operated for only a limited time (usually 10 to 30 days) or restricted performance to such an extent that even testing the product was just no fun at all. But now there has been a sudden increase in the number of student versions, which are certainly still restricted with regard to their power but now make it possible to handle more demanding projects. Ansoft have also changed their views and have put a free student version of Ensemble on the Internet. This name conceals the well-known microwave simulation program Harmonica and the system-planning program Explorer. One excellent feature is that before downloading you are given a precise list of the extent of the restrictions introduced and of their locations and you can still download 75 megabytes ...

address: http://www.ansoft.com

IrfanView32

What PC user hasn’t come across the problem of a graphics file which the systems on his / her computer can’t open? This loophole has now been closed by IrfanView32. With this new freeware you can now open and convert any – and I really mean any – graphics in even the craziest formats. One further detail is that you can also use it to set up a slide show. So we should all have this useful software handy on our PC’s.

Maury

A well-known name, famous as manufacturers of high-quality and expensive microwave test rigs. It’s always worth visiting this homepage for, in addition to data sheets for all their equipment, you can also find some very carefully written application notes. They not only describe the precise applications for the equipment in connection with the most frequent measurement tasks, but they also lay out the theoretical principles involved once more and present them clearly – something users can always profit from. We can particularly recommend the two introductory brochures covering the measurement of intermodulation and noise.

Address: http://www.maurymw.com

JFW

Anyone looking for a manufacturer of attenuators and switches of all sizes for the microwave range should download the entire catalogue of this company (over 150 pages) from their homepage in pdf format . In addition to basic introductory information, there is an enormous range of products available there, and you’ll undoubtedly find something to solve your problem.

Address: http://www.jfwindustries.com

Test & Measurement World

The homepage of this technical review has an interesting Article Archive, which you can access through the search function in the usual way. There are also some publications on HF and microwave technology in html or pdf format ready for downloading. This service is free and it’s always worth going back from time to time to see what’s new.

Address: http://www.tmworld.com/index.htm

dB

Everyone knows this measurement unit and so it’s no surprise that a company should have chosen it as its name. Here you can find microwave amplifiers and oscillators for sale and, as is so often the case, there is also some good technical information available on the homepage.

Address: http://www.microwavedB.com

EZNEC

The mist is slowly clearing away with regard to short-wave and VHF aerial simulation, and it has now become very clear what’s worth buying or testing. Anyone going into aerial simulation programs in more depth will know that all sophisticated software uses the codes from NEC2 and / or NEC3 as the core for the simulation. NEC4 is expensive perfection, which can be used even for simulation in the near field and close to the ground. But it is very expensive and moreover it is still an American military secret.

Address: http://www.eznec.com

Internet Treasure Trove article links from VHF Communications 2/2001

Synergy

The well-known manufacturer of radio-frequency and microwave components has expanded its product range and (as usual) posted the associated documents on its homepage. Of special interest here are some very well put together short tutorials (in PDF format, ready for download) on the subjects of couplers / modulators and demodulators / mixers / synthesizers / VCO / power dividers.

Address: http://www.synergymwave.com

Trompeter

This firm’s homepage offers comprehensive information on radio-frequency plugs and sockets. In addition to catalogues and application notes, there is also an interesting publication. For radio-frequency circuit developers in particular, this publication is indispensable, as it includes all the tricks and tips required with regard to the subject of radio-frequency printed circuit board drafting and the correct ways to connect plugs or sockets with a printed circuit board:

Address: http://www.trompeter.com

Philips

Anyone who has not visited the Philips homepage for some time will be pleasantly surprised, not only is the presentation now very good and user-friendly, but the number of prepared application notes has risen to well above 400. There is now 35 megabytes of information of interest to radio-frequency engineers.
The data referring to RF power amplifiers have multiplied at great speed. Something very recently added is information on such topics as circulators or electro-magnetic compatibility. However, we should explain how to get to where you want to go, for as so often a little game of hide-and-seek takes place:

Address: http://www.philips.com

Sonnet Lite / Dr. Mühlhaus

The German agent for Sonnet single-sideband modulation simulation software (for precise information on using the free test version Sonnet Lite, see VHF Communications 2/2001, Page 66) is very active, and has prepared supplementary programs on his homepage to be downloaded free. He has written some of these himself.
His "Sonnet tips and tricks" are very useful, as is the "geo3D" program for the three-dimensional representation of the simulated structure. Just as important is "dconvert" for generating "S-Parameter-Files in Touchstone format" (*.S1P or *.S2P) from the simulation result, etc..

Address: http://www.muehlhaus.com

Obtaining driver software

You have a new PC and you want to carry on using the hardware you’re used to as well. So you soon find yourself faced with the problem that (in the main) existing drivers often do not run on the new machine, because it has more up-to-date operating systems; so you are in urgent need of updated drivers for the new installation.
Where can you get the new drivers you need in a hurry? The address below is the most important one in this context, and you can find practically everything you need concerning current software and suitable links there.

Address: http://www.heise.de/ct

Meteosat / Eumetsat

Have you heard? The next generation of Meteosat weather satellites (MSG = Meteosat Second Generation) is on the starting line. The first rocket was due to be launched in October 2000, but this has been postponed until July 2001. So there’s still enough time left for anyone who is interested to become familiar with the history of Meteosat, the current technology, the transmission technology for the newcomers (almost everything has finally become digital...) or with all aspects of applications in meteorology or geography. You can also download extremely high-quality material by the ton, most of which comes under the headings of "Technical & Scientific Literature" or "MSG" . Those not wishing to go into the subject so deeply can improve their knowledge now and then by looking at the on-line house magazine "Image".

Address: http://www.eumetsat.de

National Semiconductors

No doubt with an eye to the ever-growing mobile phone market, this company has set up its own web site for "wireless communication". With regard to the product range, the greatest interest is aroused by PLL’s and synthesiser tuning. So we not only find very good and comprehensive application notes and introductions here, but also software for the easy calculations of appropriate circuits (Name: EasyPLL).

Address: http://www.wireless.national.com

Dayton Hamvention

The best-known American amateur radio exhibition has its own homepage. In live sound: The greatest Amateur Radio Convention in the world!
Here, in addition to the date of the next show in 2001, which lasts for more than one day (18^th. – 20^th. May), you can find everything worth knowing about flights, accommodation, and even the entry prices.
A photo gallery conveys an impression of the gigantic event with its halls, the arena and the unusually extensive flea market within the exhibition space.

Address: http://www.hamvention.org

Internet Treasure Trove article links from VHF Communications 3/2001

Aplac

Up in the far North, the Finns have been continually developing and improving their simulation program, and now we have version 7.6. We have already pointed out that the student version can be downloaded, together with all the documentation and manuals, from the APLAC homepage. However, if you send an E-mail and ask for the test CD, you will also receive some publicity material and a very useful application note. "Using APLAC to simulate RFIC Mixers". Taking a closer look at a decidedly interesting product, we find that, not only can it simulate the standard IP point measurement with several sounds, but it even has a chapter headed "Measuring Non-Linear Noise".

Address: http://www.aplac.com

Stellex

Anyone who has anything to do with mixers, needs an SMD version quickly, or just wants information on the most recent state of the art, should just take a glance at the Stellex homepage.

Address: http://www.stellexms.com

Sawtek

For anyone who does not yet know Sawtek: according to its own publicity, it is the right contact for anyone interested in SAW filters (surface acoustic wave filters) for all possible applications. Mostly SAW filters for the radio and mobile phone markets, and naturally in SMD formats as well. There’s always some interesting information here, which you can download as the most recent "Product Brochure".

Address: http://www.sawtek.com

Ansoft Ensemble

After "Harmonica", the well-known microwave circuit simulation program, Ansoft has now also put a student version of its EM simulator, "Ensemble" on the Internet for testing. This can be used to analyse well-known structures such as couplers, microstrips, patch antennas, etc..

Address: http://www.ansoft.com

Note: Such well-known products as Sonnet, APLAC, etc. are now competing with one another for the "student version market".

Yet, of course, we do not know whether all products are equally good, fast, reliable or precise. You can only test this yourself by using the different programs on a fully completed project (e.g. a patch antenna).

Microwave Journal

The well-known trade journal has taken the trouble to post the technical articles from back numbers going back to the middle of 1997 on its homepage as the "Editorial Archive" – a fantastic treasure trove.

Address: http://www.mwjournal.com

RLC

If you want to use coaxial switches in SMD format (e.g. SPDT type = single pole / double through) in your development work, you could well just take a look at this company’s site. The frequency range on offer goes from DC up to 26 GHz, but there are also couplers, dividers, terminations, attenuators, DC blocks, BIAS tees, detectors, etc..

Address: http://www.rlcelectronics.com

Internet Treasure Trove article links from VHF Communications 4/2001

SONNET Lite 7.0

The manufacturer of the well-known EM simulator, which has already been introduced here in Part 1 of the article on modern designs for patch antennas, has improved the free "Lite Version". SonnetLite 7.0 now offers expanded simulation options. Thus, for example, there are now more ports available, the online help has been rewritten, pared-down algorithms allow more extensive simulations to be carried out with the same main memory restrictions as previously, etc..

In addition, a version is now on sale with max. 32 MB main memory, but for $ 500.

Address: http://www.sonnetusa.com

Applied Microwave and Wireless

The well-known American technical revue has now archived almost all technical articles up to 1989 – like the "Microwave Journal" – and they can be accessed through the homepage. Some highly interesting subjects are covered, although even here the conspicuous copyright stamp must be respected, including the ban on reproduction. Copies of material can be obtained without charge following registration.

Address: http://www.amwireless.com

MINI-CIRCUITS

A well-known name for a very wide range of HF and microwave components (couplers, mixers, amplifier components, dividers, attenuators, etc.....). It’s worth visiting their homepage, as there you will find not only numerous documents for downloading but also an endless succession of new ideas. The most recent products are passive mixers with fabulous IP3 values going up to +38 dBm, or the interesting and reasonably priced "Bluecell Mixer".

Address: http://www.minicircuits.com

APLAC

The Finns in the far North are also hard at work: now APLAC 7.61 rolls up as a free student version with the usual advance publicity and improvements.
The offer of a 45-day full test version is very advantageous. As soon as you are actually up to speed with the student version and are coming up against restrictions in using it, due to the size of the project you’re tackling, you apply for a license and continue to work on the problem with the full version. Although the computer used must form part of a network!

Address: http://www.aplac.com

PCAAD40

If this heading sounds somehow familiar, there’s a good reason why: version 2.1 was recently introduced in VHF Communications in the section entitled "An interesting program".
The author, David Pozar (who has also been responsible for some very good technical books on microwave techniques) has developed the program quite considerably. There is now a large WINDOWS 32-bit version, with over 30 different models of antennas alone for investigation and analysis. Unfortunately though, it is no longer free, but costs $ 390.

Address:
http://www.antennadesignassociates.com

VECTRON

A manufacturer which has specialised in SAW filters, and particularly in crystals and crystal oscillators of all kinds (TCXOs, VCXOs, OCXOs, etc...) for all conceivable frequencies.

Address:
http://www.vectron.com

TACTRON

This firm has for years been a supplier of American microwave components and simulation software such as the MICROWAVE OFFICE, etc.
On the homepage you can naturally find documents covering the complete product range, but there are also some very interesting new items:

Address:
http://www.tactron.de/mytactron

ARCOM

Anyone wanting to become more closely acquainted with dwarf wave techniques will find a manufacturer of power amplifiers, low noise amplifiers, down and up converters, transmitters and receivers here. Not only is it interesting to glance at the many data sheets available, but it is also worth keeping an eye on the new "Education Page". This is intended to become a forum in which like-minded people can exchange and extend their knowledge.

Address:
http://www.arcom-inc.com

IONBEAMMILLING

You read it right: not only is that the firm’s name, but they "really do carry out milling with ion beams".
Here all possible microwave and millimetre structures (couplers, attenuators, filters, etc.) are marked out, for example on gold-coated ceramic plates, using the "atomic sand blasting process" (actual quotation from firm!). The way the procedure works is also precisely described. Truly the most modern high-tech manufacture - genuine information for those interested.

Address:
http://www.ionbeammilling.com

Internet Treasure Trove article links from VHF Communications 1/2002

Stanford Microdevices / Sirenza Microdevices

Here you have to make a quick re-adjustment, the well known firm of Stanford has suddenly changed its name. Nevertheless, its activities remain unchanged. They still make new low noise amplifiers, mixers, gain blocks, etc for the frequency range between 0 and 10GHz.

Address:

http://www.stanfordmicro.com

Flex-PDE

The Internet has some new EM simulation software, known as "Flex-PDE" for 2D and 3D analyses in the microwave range. This is especially suitable for the extremely high frequency range between 10 and 100GHz. Those interested can download the free test version.

Address:

http://www.pdesolutions.com

Linmic

Again, something similar, but centring on what is (according to the publicity) a combination of EM simulators and layout orientated CAD software packages which is unique in the world. Here too there is a demo version for testing.

http://www.linmic.com

Here you can, find out all about microwave diodes, i.e. Schottky diodes, PIN diodes, tunnel diodes, varactor diodes, etc. Naturally, there are also comprehensive catalogues, data sheets and application notes.

http://www.metelics.com

Marki Microwave

Never heard of them? Well, anyone who’s looking for fast doublers, mixers, multipliers or converters at reasonable prices for the frequency range between 0 and 40GHz in SMD format should take a glance at this page.

http://www.MarkiMicrowave.com

Rf Nitro

This site has nothing to do with artificial fertilisers or explosives. It deals with the cutting edge of MMIC development in GaA’s or GaN technology. A wide range of products for the microwave range and some excellent application notes practically compel you to visit this site.

http://www.nitro.com

National Instruments

A company manufacturing and marketing measurement technology hardware and software on such a large scale (think of "LabView", for example) is naturally a real Treasure Trove for those with relevant interests. Here we find not only data sheets and test software CD’s but also separate document packages for users and developers. Also on offer are tutorials on various subjects and product groups.

http://www.ni.com

Internet Treasure Trove article links from VHF Communications 2/2002

KACHINA

Here, among other things, we can find a set of wiring diagrams for the Transceiver 505DSP, which is no longer manufactured. (Obviously you can still obtain residual stocks of this transceiver at favourable prices.) You can also look at some application reports. Address:

http://www.kachina-az.com

Synergy

The well known microwave component manufacturer has made a really big effort once again and has completely revised its homepage. So now under a specific heading we find not only data sheets but also appropriate application notes, technical documentation and technical articles (from periodicals). Treasure Trove indeed!

http://www.synergymwave.com

NEC Archive

The website of Ray Anderson, WB6TPU, contains an NEC archive; here, among other things, you can download the Yagi design program YGO3.ZIP, this is also available from the VHF Communications web site.

Analog Devices

A big name in the field of IC production, mainly active in analogue circuits, D/A converters, RF-ICs, etc. and also in digital signal processors. The technical documentation has been greatly expanded, and especially the basic tutorials (e. g. on digital signal processors). You can look around for hours now and find more and more new stuff to downlowad.

http://www.analog.com

Software Radios

Under the precise address given below:

The Longwave Homepage

Amateur activities in the longwave area are a really new challenge for do-it-yourselfers and for anyone who enjoys fiddling about. And it was only a matter of time until like minded people met up and got organised on the Internet as well. This homepage is the first address anyone interested in longwave reception should visit, as here you can find the technical equipment for getting started, both theoretically and practically. And naturally there are lots of links to similar sites or interesting documents.

Internet Treasure Trove article links from VHF Communications 3/2002

Agilent

Following the change of name and the re-organisation of the company (formerly Hewlett Packard), calm is slowly returning to the homepage as well, together with the quality that we were used to. So it’s worthwhile taking another trip through the various areas on display, and in particular having a look at "Semiconductors/RF and Microwave", where all the previous application notes are back with a new look together with some genuinely new items.

http://www.agilent.com

 Texas Instruments / Burr Brown

The sector’s giant and the inventor of TTL technology has made a discovery. High quality analogue technology is also important, and has a big future in connection with modern digital signal processing. So it’s not a question of re-inventing the wheel, it’s more that a well-known and worthy representative of the analogue branch has simply bought it up. So we also find the former Burr-Brown application notes here in the TI homepage in downloadable form.

http://www.ti.com

The earlier DOS program package from the good old HP days can now be obtained free of charge once again in the most recent Windows version from the successor company (Agilent) and can be downloaded from the Internet.

http://www.hp.woodshot.com

 Alpha Industries

This is an important address for all types of microwave semiconductors. The "millimeter wave squad", in particular, will not only rejoice over the circuits on offer for applications from 20GHz upwards, but will also treasure the data sheets and application notes prepared. What is also really great and very informative is that a whole collection of splendidly crafted complete circuit diagrams of modern transmitters, receivers, etc. can be fetched onto your own computer. Even diagrams and formularies are available as aids to development.

http://www.alphaind.com

 DSP Guide For Scientists And Engineers

A specialist volume more than 600 pages long, excellently produced from both the technical and educational points of view, and dealing with digital signal processing, that wouldn’t be cheap, would it? And yet it can be, if you take the trouble to download all 33 chapters from the PDF files individually, free of charge from the author’s homepage. It does take some time to transfer 20 megabytes, but that isn’t the problem. Every time you download a chapter, the humorous author makes comments such as: "Do you really expect your laser printer to do this?" or "I think now it’s easier for you to buy the hardback edition", etc..

http://www.dspguide.com

 Linear Technology

Another specialist in analogue circuits: from operational amplifiers through AD converters, right through to switch regulators for power supplies.

http://www.linear-tech.com

 RFMD (RF Micro Devices)

Another well-known manufacturer of standard microwave components, producing everything needed for circuit development from amplifiers or mixers through the front end right to the attenuator or the switch MMIC. Support is exemplary once again, in the form of many data sheets and technical notes that are available free of charge from the homepage.

http://www.rfmd.com

GraphTrack

The GraphTrack program, formerly marketed by Silicon Solutions, is available in an updated version for the MTI interface for satellite rotors.

Address:

http://www.rcallen.com

Internet Treasure Trove article links from VHF Communications 4/2002

PUFF and LINUX

It’s taken a long time and more and more people have been asking for it. The homepage referred to below finally provides an adaptation program for operating the much-loved microwave CAD program Puff using Linux.

http://wwwhome.cs.utwente.nl/~ ptdeboer/ham/puff.html

Applied Radio Labs

This is a company in Australia that specialises in the problem area associated with VCO, PLL and noise. Thus we find here the "SimPLL" program for the design, optimising and simulation of PLL synthesisers. The program can be downloaded free. Of still greater interest are the basic articles on these subjects in the on-line tutorial, which you really should look at – very well put together and easy to understand, in particular the sections on the basic facts about noise or sideband noise.

http://www.radiolab.com.au

Amateur Radio Download Page

There must certainly be a lot of these on the Internet, but this page offers a good mixture for various applications. Thus we find the following areas represented here:

• Legislation and regulations concerning amateur radio
• Low-frequency decoder
• Sat programs
• DSP applications
• Telex and packet radio programs
• Morse practise programs
• Weather satellite image evaluation
• Log book programs
• Locator programs
• Collected test questions, etc.

http://www.qsl.net/df0che/dwn.htm

FAISYN

The proven DOS filter calculation program, available for years, now has a Windows successor. It’s easy to operate, a good, precise program, and it has the usual modern printing options. It comes over as a worthy representative of its name. However, the program must be either deleted or registered after a 30-day test period. Unfortunately, you then have to pay $99...

http://members.aol.com/faisyn/faisyn.htm

Technical University Of Munich

The Electro-Technical Institute has collected some interesting things that can be downloaded from its RF section. We don’t merely find collections of formulae and nomograms for all possible areas of high-frequency engineering here. This homepage is also very important as a source of diagrams with, in particular, the current limiting values for the electrical and magnetic field strengths of signals.

http://www.hfs.ei.tum.de

MSTRIP40

The title story in issue 2/2002 of VHF Communications dealt with this free EM simulator, and there are some good new features here. Professor Splitt has now posted the unrestricted full version on his homepage to be downloaded. The program makes it possible to simulate structures with a maximum of 5 layers.

http://www.intek.e-technik.th-kiel.de/splitt.htm

Microwave Engineering

This is one of those typically American technical reviews (similar to "Microwave Journal") with a motley assortment of advertising, situations vacant and technical articles, which can be obtained free of charge following registration. There are also sections such as "News" or "Features", which represent outstanding sources of information for the specialist. And you can also search the archives of previous issues.

http://www.gaasnet.com

Internet Treasure Trove article links from VHF Communications 1/2003

Antenna Design Calculator

Anyone who visits the homepage of "Q-Par Angus" in England is entering a forest of microwave antennas. Innumerable microwave antenna types, going up to 100GHz, are designed, manufactured and marketed there, and naturally there are detailed descriptions as well. There’s certainly a lot of useful information available here.

Address:
http://www.q-par.com

AppCad , Version 3.0

This is brand new, the most recent Windows version of the "Personal Design Assistant for RF, microwave and wireless applications". A very long time ago, when Agilent was still called Hewlett Packard, this program existed on a 5 ¼ inch diskette. This ancient version can also still be downloaded, but it won’t work properly except with pure DOS. On the plus side, it still contains some things that were deleted later such as spiral inductor design, etc.

Address:
http://www.hp.woodshot.com

Radio Waves below 22kHz

Have you heard of Schumann resonances? Or can you sketch a Whistler receiver? If you want to close such gaps in your education, just pay a visit to this Italian homepage. It can be described as compulsory reading for those people who want to get involved with the interesting area of VLF, ULF or ELF. Anyone landing up here will find innumerable recommended links to follow.

Address:
http://www.vlf.it

Transmitter Tour

What would it be like, just for a change, to go on a technical tour through various radio stations such as "Voice of America" etc. To savour the technical details of such high powered transmitters, as revealed in many illustrations and detailed explanations? Then just go to "Jim Hawkin’s Radio and Technology Page". The author has assembled more than 300 photos, and there’s also plenty of material on the history of wireless transmission technology. Naturally, there are also sub menus and links for such modern subjects as DAB, etc. Extremely entertaining and never boring! If you want to learn a bit about the principles, then just enjoy "Electromagnetic Radiation explained"

Address:
http://hawkins.pair.com/radio.shtml

A Site for the practising RF engineer

That’s what our next site’s called. A lot of stuff has been assembled here that people need more and more frequently. Two very fine and well produced features are the tutorials on direct conversion receivers and fractional N synthesisers. But there is also a complete page containing nothing but links to companies who offer application notes for downloading. Another important thing, here you can finally download the standards for the various modern communications systems such as GSM, 2G, GPRS, WLAN, WDCDMA etc. onto your own computer.

Address:
http://www.rfengineer.cc/

RF-WEB

As down-to-earth as the name implies. A very comprehensive but very unimpressive site greets you, containing nothing but links to interesting aspects of radio frequency technology. But if you take a closer look at this list, then you will very soon be mentally begging the author’s pardon, because not only is there an unbelievable amount available here, but it’s a real Treasure Trove.

Address:
http://www.rfweb.com

Online Education

Internet learning is continually on the increase, in our specialist subject as well, so we’re giving two interesting links for better information here. The material available there is not intended for immediate downloading but for on screen training and/or further education. Professors, teachers and specialists have created the splendid lessons or learning packages, which makes for willing pupils. You’ll have no trouble getting stuck in here, so to speak.

Address 2:
http://www.iec.org/online/tutorials

RF-Cafe

This, as you might expect, is a site where you just sit back and have a good old rummage around. You will undoubtedly know of, or you’ll already have, a lot of the literature or software mentioned here, but the author never sits still and is always on the lookout for interesting new items (such as a waveguide filter designer).

Address:
http://www.rfcafe.com

Internet Treasure Trove article links from VHF Communications 2/2003

Ansoft

The free download site of the well known supplier of simulation tools has expanded yet again. In addition to the student versions of Serenade SV (High frequency circuit design) and Ensemble (Wireless circuits and planar antennas), we now also have "Simplorer" (Multi-Technolgy Simulation for automotive, aerospace and power design). And the very latest thing is "Maxwell SV", an electromagnetic field simulator. These are stripped down versions of the professional tools written for Windows NT and cannot be guaranteed to operate satisfactorily with Windows ME or XP.

Address:
http://www.ansoft.com

Rogers Corporation

The manufacturer of RT-Duroid and other printed circuit board materials making its very comprehensive range available, together with all conceivable technical data, in the form of pdf files. There is also a free download area containing a stripline calculator and a "Flex-Analysis" program for investigating modern printed circuit boards that can be rolled up like a cigarette with the components fitted.

Address:
http://www.rogerscorporation.com

K&L Microwave

K&L are a filter specialist who makes everything possible – well, everything guaranteed to be manufactured. From the LC filter to the bandpass wave guide filter, from the cavity filter to the duplexer, the customers can have whatever they want. The homepage includes a collection of pdf files on complete filters, also a download area, so that the filter data can be matched with suitable programs, and consequently you can have your own filters made. Of great interest, and a good test for your knowledge, are the two pages of filter definitions and filter specifications in the "Products" section. This brings together all specialist filter terminology with a clear explanations.

Address:
http://www.klmicrowave.com

Microwave Office

Another microwave simulation program, and another one that makes a free test version available for 30 days. It is probably not so interesting for the private user on grounds of cost alone, but the homepage does contain a lovely collection of application notes with many practical examples. It is worth more than a casual look and to see where the associated literature sources can be found (e.g. for hairpin filter design).

Address:
http://support.mwoffice.com/appnotes/listnote.aspx

RF Micro Devices

Manufacturers of components and IC’s for modern communications technology are probably not in an enviable position. The intervals at which the entire production range has to be almost completely shaken up and renewed have become shorter and shorter. That is true of this company too, who among others, supplies the mobile telephone, GPS and Bluetooth markets.

Address:
http://www.rfmd.com/prodTechnical.asp

Simtel

The name conceals a provider offering any amount of free software for downloading. Of particular interest for people like us is the page on "MSDOS Electrical Engineering Programs", because this contains antenna calculation programs, filter programs, EM Field Analysers and much more (and you’ll meet up with old acquaintances, such as "faisyn", "pcaad21" and "filtry"). It’s worth rummaging around a bit here

Address:
http://www.simtel.net/pub/msdos/electrcl/

UK Microwave Group

You should drop in on these guys regularly, as there’s always something new. This time it’s the free student version of the filter program "elsie", but there’s also the "Hardware" section, and don’t forget to take a glance at the "scatterpoint" magazine.

Address:
http://www.microwavers.org/index.htm

Anadigics

They are a company who manufactures every possible type of semiconductor and IC for RF and microwave applications and not only have magnificent pdf data sheets on the Internet, but also provide application notes to look at and generally rummage around in. You can also find a splendid range of items for downloading at the following address:

Address:
http://www.anadigics.com/products/appnotes.html

Data Bookshelf

If you urgently need the data sheet for some component or other and you know the manufacturer, you should keep this link handy. Here you will find the Internet addresses of practically all semiconductor manufacturers, beautifully laid out in alphabetical order. Just one click and you’re connected to the homepage of the company you want.

Address:
http://www.crhc.uiuc.edu/~dburke/databookshelf.html

LC

No, this is nothing to do with a tuned amplifier circuit or with any kind of filter circuits. We’re talking about a free EM simulator (e.g. for calculating microwave structures or patch antennas). Free up to now for users of Cray or SGI super-computers, but suddenly there is also a LINUX / Intel x86 version available for downloading following registration. There must be lots of people who’d be interested in that.

Address:
http://lc.cray.com/

FIR filter software list

Anyone who has ventured into digital signal processing must have wanted to program digital filters. This site provides a comprehensive list of FIR design software that can be downloaded or used on line. And naturally there’s an important link to other DSP pages.

Address:
http://www.poynton.com/notes/links/dsp-links.html

Micromanipulator

A small site admittedly, but a splendid one for all that. It has an outstanding list of the characteristics of standard contemporary microwave connectors, together with some good comments on correct microwave circuit metrology.

Address:
http://www.micromanipulator.com/RF-Notes.html

Internet Treasure Trove article links from VHF Communications 3/2003

Antenna tools

This is really a little treasure chest, in addition to the assembly instructions for a 137kHz receiver and many other things, there is also a special page for antenna freaks with "Antenna tools". These are Java scripts to calculate everything conceivable on line. Would you care for a little taste? "Conversion between Field strength and received power / Field regions / Isotropic losses of free space radiation / field strength, field area and received power…..etc."

Address: http://www.giangrandi.ch/jack/main.shtml

TCS Online conversion page

More of the same, with the Java scripts for rapid calculation of every possible aspect of telecommunications, but this time provided by a big company and on offer to customers or to anyone interested. Considerably more extensive than the previous link, but just as interesting.

Address: http://www.tcstx.com/conversions/online_conversions.htm

Radio Mobile

The simplest thing is just to quote, word for word, the heading and description for the freeware which can be obtained here:

Address: http://www.cplus.org/rmw/english1.html

World Wide Web Links

Any number of interesting downloads await the radio amateur who calls up this page. The site covers both databases and online tools for calculating many things (not only relating to antenna technology or to circuit engineering). Just take a peep!

Address: http://www.w4rrc.org/RARCClubWebLink/WebLinkReferenc.html

Pearl Scripts of Interactive Design Software

Somehow this is slowly becoming the fashion, interactive online calculators for telecommunications and antenna engineering, but the ambition (or the competition!) is obviously gradually becoming so intense that each wants to outdo the other. Just take a look at this page....

Address: http://www.qsl.net/n9zia/wireless/page09.html

AVX

Something different for a change. Anyone who wants to get well informed on the smallest details of RF and microwave capacitors might well want to click on this link. In addition to data sheets, spice models and software, there are well compiled and informative articles to study.

Address: http://www.avxcorp.com/SpiApps/default.asp

Spread Spectrum

Do you just want to become a bit more familiar with this area via a good tutorial or simply to find out about the basic principles? These links can give you some confidential help.

Address: http://www.ncafe.com/chris/pat2/index.html

RF Avenue

That sounds like a pleasant stroll, and that’s what this is. Mind you, it takes rather a long time and it’s a stroll around the computer, for by the time you’ve thoroughly explored this page and tried everything out, it’s long past midnight.

Address: http://www.newwaveinstruments.com/resources/rf_microwave_resources/

YDI

Please take a look yourself, as here too there is information on offer relating to what you can learn and calculate.

Address: http://www.ydi.com/calculation/

Ingecom

Here you can obtain a very well-written article entitled "VHF and UHF Antenna Design". It is really rewarding, either as a stimulus to further research or as a refresher of what you may already know.

Address: http://www.ingecom.ch/Pics/an_antenna.pdf

Holaday

This is something for people who are interested in EMF (electromagnetic field measurements), whether for professional or private reasons, in order, for example, to get to grips with the problems of risks associated with EM fields. Very good application notes and articles make it worth clicking on.

Address: http://www.emctest.com/Holaday/appnotes.htm

Antennex

And finally, another big jar to rummage around in, as here too the concept of antenna engineering is stretched a long way and includes many associated areas.

Address: http://www.antennex

Internet Treasure Trove article links from VHF Communications 4/2003

That's the heading above the lists of links and downloads on this homepage. But we're dealing with tutorials on the basic principles here, the list is never ending, and it's impossible to itemise everything there is here on this subject. So just have fun rummaging around!

Address:
http://members.fortunecity.com/ xe1bef/theory-antennas.htm

Radiometrix

A company which specialises, in particular, on data transmission and modems, including those operating over radio routes. But there are also some neat application notes for the RF freak, quite apart from the many data sheets and other information regarding interfaces.

Address:
http://www.radiometrix.com/

TX Lines, Antenna Systems, PC Joystick

We don't want to spend all our time talking about antennas, but a homepage with such good tutorials and with so many different applications deserves a mention.

Address:
http://www.tmeg.com/tutorials/tutorials.htm

Radio Waves

The site's name gives you a pretty good clue: it deals with developments and products relating to electromagnetic waves. The main theme is antenna development and the production of complete antenna arrays. And because in this kind of work you have to pay very close attention to the customer's wishes, there's also an extensive planning section. One splendidly attractive gift from these people to all RF freaks is the "RW calculator" for calculating and planning every last little thing relating to antennas and receivers, which you can download free of charge. This is really something great, with many different applications of all kinds!

Address:
http://www.radiowavesinc.com/html/414_rf_system_planning_tools.cfm

Longwave links

Just for a change, here's something in German, and something for the community of longwave fans. This homepage is a must for anyone wanting to know more about this field and this technology.

Address: http://home.t-online.de/home/hhcuno/afu/ longlink.htm

Amateur Television and high speed data signalling

Even though this homepage is hosted from France, you don't need any knowledge of French, as there is an English version. We are certainly grateful to the owner for the opportunity to download information on well documented DIY projects, going up to 2.3GHz, which will gladden the heart of any do-it-yourselfer.

Address:
http://perso.wanadoo.fr/jf.fourcadier/accueil/accueil_e.htm

G4FGQ's Software Site

An interesting page, put together in a way that's just right for the amateur and for anyone who likes fiddling about with RF projects. You can spend a lot of time here searching, investigating and downloading. Most of this site is about programs, all "home made" and all similar in appearance. So you know at once what it's all about, and you don't have to spend a long time in experimental operations. Very rewarding and highly recommended!

Address:
http://www.btinteret.com/~g4fgq.regp/#S102

W2BRI's Magnetic Loop Site and PA3CQR magnetic loop antenna page

As always on such sites, the more you nose around and the more stones you turn over, the more treasures you unearth. Very enjoyable and informative to see everything concerning loop antennas summarised here.

http://www.iri.tudelft.nl/~geurink/magnloop.htm

Alphabetically arranged radio technology links

A site like this makes it considerably easier and more comfortable to search for a program, an article or a homepage to solve a problem.

Address: http://home.wanadoo.nl/~a.schipper/fuurllinks.htm

Myer's Engineering International

23 years of experience with radio communication systems and antennas... that's what it says in the introduction to this site. Another homepage which can reveal masses of new or fascinating facts for those with an interest in such matters. Seek, and ye shall find...

Address:
http://www.myerseng

Internet Treasure Trove article links from VHF Communications 1/2004

SONNET

There’s some very important news for those using the free “Light” version of this familiar EM simulation program: the newest update gives you free access to something people have been waiting for a long time. Now you can finally connect an exciter port into the centre of the structure as well, and not just (as until now) to the wall of the metal box which is required for the simulation. So now, for example, patch antennas can also be powered directly on the patch and not just via a tiresome long supply line. That’s really a concession worth having!

Address:
http://www.sonnetusa.com

University of Ulm

And now for something completely different: here you can find the processes taking place in waveguides, couplers, circuits and filters, etc, presented in vivid animated form. And to round things off, both a demo version of the analysis program in use (TLM = Transmission Line Matrix Method) and a link relating to the animation program are available. Very informative and amusing, even as revision for people who already know everything!

Address:
http://mwt.e-technik.uni-ulm.de/lehre/hf-anim/mefisto/

Engineers Heaven

The heading for this homepage, run by a Turkish university, makes an interesting promise. Just looking at the sections on offer is a pleasure, as you contemplate the data available concerning microwave technology.

Address:
http://www.ee.bilkent.edu.tr/~microwave/magnetic.htm

EMC Technology

This website has some interesting application notes, which you can study and download, they are mainly concerned with couplers and circulators. But they also include information on the practical fitting of SMD components on microwave printed circuit boards.

Address:
http://www.emct.com/softwaretools.htm

TMEG

This is an acronym for "£The Millenium Education Group" and consequently there are some very nice tutorials. The two sections on "Transmission Lines" and "Antennas" are particularly interesting, but there is also "Babylonian Mathematics" or "an electronic needle gun". So, for anyone who’s interested .....

Address:
http://www.tmeg.com/index.html

RF Tools

Another of those homepages where you almost find yourself feeling giddy: innumerable RF tools and documents of all kinds are on show for interested users to sniff out and download. You just can’t count everything there is here. I recommend you set aside sufficient time, then just open up the site.

Address:
http://rfengineer.cc/rftools.htm

Chenjian's Electronic Packaging

Anyone looking for up-to-date information on the state of manufacturing technology, including housings for integrated RF components (amplifiers with integrated coils, capacitors and resistors, couplers, etc.) should have a look at this site. The content ranges from information on trends, technologies, production processes and opinions on reliability right through to material trials, and finally an "Online Dictionary".

Address:
http://chenjian.virtualave.net/packaging/tech/other/rf/rf.htm

Faustus

The classical touch extends beyond the company's name to its product, MEFiSTo.
This is (another...!) EM simulator, but here, for a change, the company has found a different way to awaken customers' interest. They're currently introducing the most recent version onto the market as a 3D simulator, and so they're giving away an older, fully operational "Classic 2D Version", to be downloaded free of charge. Quite an interesting move!

Address:
http://www.faustcorp.com/downloads/index.html

MURI

Or, to reveal its full title: "The Multidisciplinary University Research Initiative (MURI) for High Power, Broadband, Linear, Solid State Amplifiers at the Cornell University".

Fortunately, these friendly people do not lock their findings and their documents away in the safe but make them freely available. But clearly not without reservations, or maybe an enthusiast for memory games is in charge of the homepage! There is no index, and everything is actually hidden away behind anonymous report numbers in a huge file, and it really is like playing some game. You have to uncover and examine everything first to find out whether you can get anything out of it. Luckily, the hit rate is really excellent......

Address:
http://iiiv.tn.cornell.edu/www/schaff/muri/reports/

Jim Hardy's Homepage

For once, something from a private individual, very nice and amusingly put together. Not just links to many of our areas (it turns out the man is also a radio ham!), but also a lot of funny material. The following section is particularly worth reading: "How Things would be different if Microsoft built cars" It’s true you have to root around a bit, but it’s worth it for what you can find.

Address:
http://www.surfsouth.com/~jhardy/index.htm

Software for the Radio Amateur

Here’s another link for people who like to spend hours surfing and rooting around. Luckily, everything is listed alphabetically, and so you can carry out a targeted search.

Address:
http://www.estpak.ee/~andrew/ham/software.htm

Internet Treasure Trove article links from VHF Communications 2/2004

ANSOFT

Once there was a feature film called “The Empire Strikes Back”. That’s what I was reminded of when I downloaded the all new free of charge student version of the RF CAD “Designer” software from Ansoft (N.B.: almost 80 megabytes!). Never have so many tools been made available for simulation and for development in general. Naturally, it takes a while to familiarise yourself with the package, but it’s worth it. Virtually all areas are covered, virtually all the calculators for RF and microwave engineering are provided. However, there is unfortunately one way in which Ansoft has stayed true to its old habits. There is scarcely any documentation – in some cases, none at all – to explain what has been left out of the student version. And of course, you find this out as soon as you ask the software to solve any really complicated practical problems. But apart from this, it’s first class!

Address:

http://www.ansoft.com/

The N4UJW Antenna Design Lab

That’s exactly what this site has to offer: any amount of software and information relating to antennas and antenna calculation. And a search through the list of links unearths some interesting things. There’s something hidden behind every item on the screen.

Address:

http://www.hamuniverse.com/

RF Avenue Resources Directory

Anyone opening up this page has a few problems, as you’re initially confronted with an endless list of documents concerning RF and microwave engineering. Of course, it’s all nicely and neatly sorted out. You could spend hours here...

Address:

http://www.newwaveinstruments.com/resources/rf_microwave_resources/
 

LC

This doesn’t refer to a resonant circuit but to the firm of LaCray – who are well known for their extremely fast mainframe computer. It’s no surprise that people use such expensive equipment mainly for complicated EM simulations of expensive antennas. But it’s not exactly obvious why the company is now allowing people to download the “LC” EM simulator used for this purpose at no charge. Certainly the computer you use should be a Cray computer, but a Linux version is kindly provided for those possessing Intelx86. Do feel free to nose around on your own. It’s really very interesting.

Address:

http://lc.cray.com/

Marska WLAN Pages

Even up in Finland there are some active people, which is why it’s worth rummaging around on this homepage. One very interesting subject is what you can find here under the heading “2.4 GHz WLAN antenna – Do it yourself”. You can choose between English or Finnish texts. But anyone who doesn’t speak any Finnish will have given up already during the search, and will not be looking for it any longer.

Address:

http://www.saunalahti.fi/elepal/antennit.html

USMICROWAVES

This manufacturer describes itself as a “manufacturer of MIC thin film technology” That means it’s a source of unending interest for those who want to be comprehensively informed concerning the state of the art in relation to all types of these active and passive microwave components. In addition to the data, layout design rules and/or application notes, etc. are also available in all sections.

Address:

http://www.usmicrowaves.com/

Semiconductor Datasheets on the WEB

This is a page full of pleasant surprises for original developers and anyone who likes messing around, as everything here is nicely and neatly alphabetically sorted and  frequently provided with links.

Addresses:

http://www.bgs.nu/sdw/

Radio Netherland

Just for a change, not pure technology, but tips and technology concerning the subject of  “Long-distance reception on the medium wave and short wave”.  Plus a collection of facts relating to the relevant antennas.

Address:

http://www.rnw.nl/realradio/practical/html/longdistancemw.html

Microwave Active Antenna Group

This site (which is run by the University of Colorado) is also guaranteed not to be boring, for the students are very active and post their well documented research results on the homepage.

Address:

http://nemes.colorado.edu/microwave/theses.html

Free Radio and Computer Programs

What makes this such a fascinating site is that you can just call up one program after another to see whether you might need them. The choice is wide, and there’s certainly enough here to be going on with...

Address:

http://www.btinternet.com/~g4fgq.regp/index.html#S102

Vectron

All about crystals - that’s the motto here. Follow the links listed to find the application notes which cover every conceivable aspect of this subject.

Address:

http://www.otek.com/products/appnotes/index.htm

Estland Amateur Group

How about a trip to see the real Northern Lights in Estonia? Here you will discover that progress and hi-tech have penetrated almost as far as the Arctic Circle. Some very interesting links and articles!

Address:

http://www.estpak.ee/~andrew/ham/ha,htm

QRZ.COM

Fertile ground for all radio enthusiasts. Here too, you can rummage around endlessly among programs and technical documents...

Address:

http://www.qrz.com/download/main/index.html

Dxing.Info

Another site to rummage around and browse in – everything you could need in relation to physics, technology and equipment know-how for DX reception.

Address:

http://www.dxing.info/

WAOTRALI

This is an animation program (Waves on Transmission Lines) from the Flensburg Technical College. It can help to clarify the propagation of signals on lines in the time domain. Various transmission signals can be selected from a catalogue, such as sinusoidal signals and pseudo-statistical digital signals of various lengths, among others. The WAOTRALI program is available for downloading from the website of the Institute for Communications Technology of the Flensburg Technical College.

Address:

under www.fh-flensburg.de/kt/

Internet Treasure Trove article links from VHF Communications 3/2004

MACOM

Microwave and millimetre wave IC products...that’s what it says in the publicity. A very nice homepage, recently revised, done by someone I know well. In addition to comprehensive data sheets and basic information, you can also find some interesting new application notes here.

Address:
http://www.macom.com/tech_app_resources/techapp_app_note.jsp?i=0

PENTEK

Technical development marches on – and that includes receiver technology too. Digital receivers, loosely referred to as “software radio”, are in the vanguard. Anyone wishing to read up on this new technology and get some idea of the concepts involved might like to download the “Digital Receiver Handbook” from Pentek. The principles, characteristics and advantages of this new technology are very nicely explained here – and, best of all, direct comparisons are made with standard analogue receiver technology.

If you explore the homepage in a little more detail and download the company’s main catalogue onto your home computer, you’ll get another surprise. Chapter 2 includes a very interesting collection of miscellaneous tutorials dealing with this area!

Address:
http://www.pentek.com/sftradcentral/Overview.cfm

Software Radio Resource Page

Something else on this subject in the form of every possible link which is relevant to it. Once you really get into it, you’ll soon lose track of the time...

Address:
http://www-sop.inria.fr/rodeo/personnel/Thierry.Turletti/SoftwareRadio.html

SYNERGY

An old acquaintance that supplies every possible type of microwave module. The homepage has been re-designed and, most importantly, there is now a much wider range of articles and application notes. Of particular interest is the documentation on offer in relation to synthesisers and microwave oscillators.

Address:
http://www.synergymwave.com/Articles/Articles.htm

Amateur Radio Soundblaster Software Collection

This homepage, which is run by Dr. Oliver Welp (DL9QJ), deals with the use of the PC sound card for all possible purposes and operating modes in amateur radio. A very comprehensive collection, especially the enormous number of links to other pages and topics.

Address:
http://www.muenster.de/~welp/sb.htm#analyzer

Electronics for physicists

The University of Kiel is behind this site, and it’s really great how teaching materials are designed and prepared nowadays. In particular, you should just take a look at the topics that cover our own area (AM, FM etc.). But there’s some interesting new stuff here even for specialists  — just call up subjects like “Types of Modulation” or “Noise and Noise Suppression”. I guarantee that you won’t be bored.

Address:
http://www.ieap.uni-kiel.de/plasma/ag-piel/elektronik/

Downconverter page

It’s both amusing and comforting when you come across sites run by other “mad D.I.Y. people”. Steve Blackmore has a day job as an electronics specialist, but it clearly doesn’t take up all his energy. So he goes in for decoding digital transmissions in a big way. He has generously made available his experience in relation to weather satellite reception, and you should work your way through all the cross-references of his homepage, where you’ll find all sorts of interesting things. Here’s a tip: there’s also a page (it’s a bit hard to find) that deals with quadrifilar helix antennas.

Address:
http://www.pilotltd.net/downconv.htm

ATMEL

It’s good to know that the well-known microcontroller manufacturer is also going into the HF market for WLAN, Smartcard, Bluetooth and the rest in a big way. Consequently, as well as containing data sheets relating to the IC’s the company manufactures, the homepage also has application notes and some good articles on the principles. Highly recommended: “A Tutorial on WLAN”, which also contains easy-to-understand information on spread spectrum technology.

Address:
http://www.atmel.com/dyn/products/app_notes.asp?family_id=657

CHIPCON

This company is from the far North – it’s head offices are in Oslo. But the product range (RF transceiver IC’s) is really first class. So it also comes as no surprise to find a very wide-ranging collection of application notes and other documentation. You can even take part in a “Wireless Quiz”, and win prizes.

Address:
http://www.chipcon.com/index.cfm?kat_id=3

Linear Technology

It must be because of the time of year, new products are sprouting in HF companies. The homepages have new products and the document collections are being extended. If you haven’t seen the new version of this site yet, you might find it all a bit overwhelming when you make your net visit.

Address:
http://www.linear.com/new/design_tools.html

Z-Communications

A specialist in VCO’s and PLL’s, with a very attractive range of products for the HF and gigahertz sectors. Also very attractive is the documentation on offer, including a lot of interesting application notes.

Address:
http://www.zcomm.com/home.htm

Internet Treasure Trove article links from VHF Communications 4/2004

Vivaldi antennas

We know that antenna developers come up with numerous “infinitely variable concepts”, which they never stop playing around with and changing – there’s no end to it. This often leads to solutions that we would never have dreamed of. The “Vivaldi antenna” falls into this category. Just take a look at how something like this makes out in a radio telescope. And if this is your kind of thing, a search engine can provide plenty of additional links on the subject.

Address:

http://brown.nord.nw,ru/vkh/vfv.1.htm

MDBC

It’s a safe bet that no one will guess what this abbreviation means, since for once, and for a change, we’re dealing with an interesting and meaningful application of high-frequency technology in medicine. So we won’t keep you in suspense any longer. The University of Victoria in Canada is introducing the concept of a “microwave detector for breast cancer”. Since this page summarises data ranging from principles through simulation to balun and microstrip design, the high-frequency specialist will also find it worth reading.

Address:

http://www.exe.uvic.ca/499/2002b/group11/mdbc.html

Electromagnetic radiation

This is a concept that is on everyone’s lips nowadays, and is even causing many people to have panic attacks. So this homepage is extremely useful, as you can look forward to investigating the physical and technical principles, the measuring process and the range of measuring devices on offer - and there’s even a downloadable test report from the Technical Inspections Association.

Address:

http://www.elektrosmog.de/

Antenna Software

This page offers a total of 115 links for you to click on, and each one leads to a program or a set of programs for antenna calculation. The same homepage also offers any amount of practical examples, and they’re even broken down by type or frequency range.

Address:

http://members.fortunecity.com/xe1bef/software=antennas.htm

Antenna Tutorials

Would you like a bit more information about the principles of antennas? If so, please just take a look at this page, as information is presented here in an attractive form, and it’s a joy to read. There are also additional links to half the antenna world.

Address:

http://www.electronics-tutorials.com/antennas/antenna-basics.htm

Spread Spectrum

Anyone who wants to become better informed by using an easy to understand introduction to this area should pay a visit to this address. Well put together, easy to understand, not too wide-ranging and yet precise – this is the right mix for a pleasant introduction.

Address:

http://www.keytelemetering.com/ABC_of_spread.htm

Since even more interesting things are on offer, we’re also giving you the link to the main page for tutorials (“College Page”).

Address:

http://ww.keytelemetering.com/College.htm

However, if you find the Spread Spectrum introduction a bit too brief, just try this link.

Address:

http://cobalt.et.tudelft.nl/~glas/ssc/techn/techniques.html

Semi-conductor manufacturers

This is probably the biggest collection of German language direct links that you can find on the Internet. Everything’s already alphabetically sorted, and even every exotic little shop is accessible (provided it has an Internet address). But anyone taking a closer look at this homepage will find still more interesting information.

Address:

http://www.aufzu.de/semihalbleit.html

AnTeg

Would you like a few application notes on the subject of microstrips / antennas / couplers? There’s some stuff you can download here, but it’s also worth taking the time just to look.

Address:

http://www.anteg.net/html/selected_papers.html

Berkeley Ultra-Wide Band Group

There’s a lot happening at most universities, and when the right team is on hand some very interesting things come out of their projects.

For example, just take a look at the project entitled “A Subsampling Radio Architecture for 3-10GHz UWB”. Look at the way these microwave freaks present and explain their results: you can do that too (...which is why I think it’s great!).

Address:

http://bwrc.eecs.berkeley.edu/Research/UWB/pubs.htm

Wikipedia

This sounds as if it should have something to do with Hawaii and the South Seas, but in reality it’s a giant online encyclopedia and user forum in several languages. You can even contribute to it if you wish. It’s somewhat hard to describe, but all our Earthly wisdom is categorised and made available, broken down by subject. Just take a look, choosing a subject that interests you.

Address:

http://en.wikipedia.orig/wiki/Main_Page

Radio navigation

The various aspects of radio navigation and the associated processes are the section headings for a PDF dissertation at:

Address:

http://www.navtec.de/personen/acf/dd/dd_inh.htm

Modulation process

You can find a (Powerpoint) presentation on FM and combined modulation signals at the address:

http://hta-bi.bfh.ch/E/Laboratories/Telecommunication/cours/modulation/FM_special.ppt

High Frequency Electronics

This page should act as an appetiser. Firstly, it lists the good, informative periodicals that are available for our sector. Secondly, the article headed: “The Design, Fabrication and Measurement of Microstrip Filter and Coupler Circuits” can and should inspire people to a bit of DIY work. Please have a good look round!

Address:

Internet Treasure Trove article links from VHF Communications 1/2005

All about the Smith chart

You often need to print out a Smith diagram quickly in order to indicate or monitor something. On this homepage you can find everything (but everything!) on this subject. It doesn’t matter whether you’re looking for a tutorial or printed blanks or tools or books or other websites: it’s all here somewhere, all you have to do is look.

Address:
http://www.sss-mag.com/smith.html

The MINT Project

Here you can find information on the technology behind a modern radio telescope or radio interferometer for measuring the CMB (Cosmic Microwave Background). The receiver and evaluation technology is very interesting, but then the links to appropriate CMB tutorials etc. are good fun as well.

Addresses:
http://background.uchicago.edu/
http://wwwphy.princeton.edu/cosmology/mintweb/

Collection of antenna design software

Just another little collection of CAD programs for antennas. Things keep turning up here that you didn’t know before.

Address:
http://www.dxzone.com/catalog/Software/Antenna_analysis/

The Designer’s Guide

This link’s title doesn’t tell you all there is to be found there: the best plan is to search in every nook and cranny and open every file. Some very nice application notes!

Address:
http://www.designers-guide.com/Analysis/index.html

Summitek

You won’t be here long before you are amazed, as this company’s area of activity is inter-modulation measurement. And the publications available for downloading are on a suitable generous scale. And of course, we can’t do without an IM calculator for doing calculations at home.

Address:
http://www.summitekinstruments.com/passive/appnotes.html

Millitech

Here’s something for people who work with the higher frequencies in the millimetre wave range. The link in question leads to some interesting technical articles and application notes.

Address:
http://www.millitech.com/cadiv/technotes.htm

LC Filter Design

Anyone who has to develop an LC filter in a big hurry usually turns to our tried and tested “fds.zip” or “Faisysn”. For those who are in a real hurry but don’t have these programs installed on their computers, there’s this online calculator. You just key in the data and press <Enter> - and you’ve already got the component values, the circuit and the simulated attenuation path on the screen. Slightly simplified, it’s true, but the readings are absolutely correct. Do please try it out.

Address:
http://www-users.cs.york.ac.uk/~fisher/lcfilter/

Besser

Besser (“better”) – it sounds like an incentive for someone’s own work ethic, and in fact it does have something to do with that. What’s actually behind the name is a company that is mainly active in the field of further education in the RF and communications technology area. Not only are these people kind enough to let you download  quite a lot of good calculators for HF engineering, but there are also first-class articles on offer as “BesserBits” (“Better Bits”) covering various subjects (DSP / noise measurement in mixers, etc.).

Address:
http://www.bessernet.com/index.html

Cubical Quad Antenna Calculator

If you’re planning a project like this, you need only click on this page and then you can design the whole antenna, right down to the mast.

Address:
http://www.softcom.net/users/kd6dks/quad.html

JFW

And here’s another lovely little microwave RF calculator. Very nice, very practical. Just give it a try.

Address:
http://www.jfwindustries.com/RF_Conv_Sign_up.htm

Internet Treasure Trove article links from VHF Communications 2/2005

Radiall-Larsen

If you need to refresh your basic knowledge of antennas, or you want to gen up on the problems and concepts associated with modern WLAN antennas, or to look for frequency occupancy tables, or to examine this, that or the other, you can look at problems more closely by visiting the “Technical Reference” section of this homepage

Address:
http://www.radialllarsen.com/technicalreference.htm

Andrew

This company has specialised in microwave communications systems, and can therefore make comprehensive aids to systems planning available through the Internet without charge.
The “Andrew Microwave System Planner” is very attractive and is also very convenient for use at home (...but you can find even more under the heading “Andrew Power Tools”).

Address:
http://www.andrew.com/downloads/default.aspx

Microwaves & RF

It’s worth subscribing to this free periodical, or at least taking a regular glance at the homepage and saving what interests you. You can even access old articles and complete old issues. For example, there’s a link to an article on  “Designing a low-noise VCO”.

Address:
http://www.mwrf.com/Articles/Index.cfm?ArticleID=9181

Tektronix

An old name, but a company that has remained young. In addition to oscilloscopes and anything else modern you can imagine, the firm now also provides modern RF wireless test sets. So there’s naturally extensive technical help available, together with some very interesting application notes.

Address: http://www.tek.com/

Software-3000

There actually seems to be a shop on the Internet where you can buy a huge amount of earlier versions of programs – they’re even sorted into alphabetical order! There are bound to be some “gaps”, but a painstakingly thorough search still came up with some surprisingly well-known and interesting names (APLAC 7.61 / Ansoft Designer / HFSS / Microwave Studio, etc.). And all at suspiciously low prices.
Should purchasers be worried about any legal problems here?

Address:
http://www.software-3000.com/cads/electronics.php

FCC

A famous and very well-known authority in the USA. So it’s all the nicer to have online tools for free use under this link.

Address:
http://www.fcc.gov/mb/audio/bickel/findvalues.html

RF Manuals

Version 5 of the popular  “RF Manuals” from Philips-Semiconductors has appeared.

Address:
http://www.semiconductors.philips.com/markets/mms/products/discretes/documentation/rf_manual/index.html

Jiwire

How about a lexicon in which you can find a brief and precise clarification of almost any term from modern communications technology (e. g. from “Frequency Hopping” through to all the IEEE 802 standards)? A useful address – make a note of it!

Address:
http://www.jiwire.com/glossary.htm?id=52

Martindale’s Calculators On-Line Centre

No detailed explanation needed here: someone has collected together everything he could find on calculators on the Net from all over the world, sorted the information and made it available to other people. There seem to be over a thousand titles listed, so have fun rummaging around!

Address:
http://www.martindalecenter.com/Calculators.html

Internet Treasure Trove article links from VHF Communications 3/2005

145GHz amateur band

Variety is the spice of life – of course everyone knows this saying. Why shouldn't it sometimes be some completely different frequency ranges? So anyone who wants to take a trip to such high frequencies should begin by taking a look at this page.

Address:
http://www.mgef.org/145ghz.htm

136kHz

Anyone who, in contrast, is attracted by really low frequencies, will find an attractive little range of items here - circuits, antennas, ideas, etc...

Address:
www.qsl.net/on7yd/136brew.htm

Tele-Tech

They are a company that produces all kinds of things for RF technology, such as mixers, directional, other couplers and dividers. Not only is it interesting to glance at the specifications of the components (for example, there's a tiny little directional coupler which covers a range from 1MHz to 1GHz), but the application notes are of interest too.

Address:
http://tele-tech-rf.com/prodselection.htm

EM-Wonder

Those who like to simulate their circuits before testing the first prototypes will enjoy this site. Not only will they find links there to various SPICE model lists, but also data on something really splendid: a converter that generates an S-parameter file for simulation.

Address:
http://www.emwonder.com/spicemodels/

PlexTex

Some more people who are very active in the modern communications technology sector and supply interesting modules or components. There is a very informative list of the “Technical Papers“ available, which should make developers' eyes light up straight away. For example, “A 2 -18GHz Receiver Frontend“ or “A Monolithic, 2 to 18GHz Up-converter“ or “RF Mixer Design“ or “Synthesizer Design“ or....

Address:
http://www.plextek.com/technicalpapers.htm#

Broadband multi-function antenna suitable for incorporation into vehicles

Something in German for once - though the bad news is that it takes a lot of downloading This modest and unassuming title conceals a Karlsruhe University doctoral thesis 200 pages long, with a good introductory section on the basic principles of antennas.

Address:
http://www.ubka.uni-karlsruhe.de/cgi-bin/psview?document=/2001/elektrotechnik/6&search=/2001/elektrotechnik/6

Tripod

Anyone looking for interesting programs for “fiddly little jobs” should make a note of this address and pay the site a visit from time to time. New items appear here at regular intervals.

Address: 
http://members.tripod.com/michaelgellis/software.html

Anadigics

Here we have an online calculator, which can be used to determine all the important characteristics of a receiver if the various stage characteristics are entered. These characteristics are: overall amplification, total noise factor, spurious free dynamic range and noise floor in dBm.

Address:
http://members.tripod.com/michaelgellis/anadigic/Receiver.html

Directional Couplers

An easy-to-understand and accurately written introduction to the characteristics of directional couplers, including illustrations and formulae. Compiled as an online lexicon of RF technology by Bilkent University in Turkey.

Address:
http://www.ee.bilkent.edu.tr/~microwave/programs/magnetic/dcoupler/theory.htm

GlobalSpec - The Engineering Search Engine

There's not much explanation needed here: anyone needing links in connection with a problem or a term should try their luck here. Normally you end up with more information than you can use.

Address:
http://www.globalspec.com/

Internet Treasure Trove article links from VHF Communications 4/2005

MAXIM

A very well-known name among IC manufacturers. This company has markedly increased its activities under the heading of “Modern wireless communications technology” and massively increased the quantity of application notes are available. All of this has been revised and now appears with a new look that makes it a pleasure just to go into various subjects a bit more deeply (which naturally include the “Wireless, RF and Cable” section).

Address:
http://www.maxim-ic.com/appnotes10.cfm/

University of San Diego / RF & Microwave Engineering

A real treasure trove for people who are interested in various RF subjects, since the pdf files available are not limited to lectures from courses. The site in fact has links to interesting articles by other people that are perfectly matched to the theme.

Address:
http://home.sandiego.edu/~ekim/e194rfs01/

Electronics Tutorials

Here's something from a part of the world in which people (looked at from our point of view) are standing on their heads. An Australian site, crammed full of interesting links and tutorials - so somewhere you can root and rummage around in for hours. And here's one thing you can search for straightway: just look for the Marine Corps “Field Antenna Handbook” (192 pages, downloadable as a pdf file). A handsome and interesting book!

Address:
http://www.electronics-tutorials.com/

Amateur radio links

There are some very industrious people in our amateur radio community, because here we have alphabetically listed links to every possible aspect of our hobby. So this is something that you're bound to need again and again, so that you can make a search more selective and make more progress. There's a lot of hard work behind this site.

Address:
http://www.dj6qo.de/intadar.htm

University of Essex / Nanofab

You've guessed it already: this site deals with the cutting edge stuff in semi-conductor manufacture and nanotechnology. This site has been conceived as an information centre for people from the appropriate technological fields, but it's also very interesting for the ordinary person who's interested in electronics to have a look behind the scenes and marvel at what can be done nowadays and how it's accomplished.

Address:
http://privatewww.essex.ac.uk/~bolat/

Agilent

When did you last visit the homepage of the successor to HP? If it was more than 2 months ago, you should just take another look at it. The RF and microwave application notes have been greatly expanded and revised.

Address:
http://www.avagotech.com/

National Instruments

By using the link below, you'll reach the “developer zone” of National Instruments, and many other paths branch out from there. Lots of literature available, but you can also access a well-constructed online lexicon of communications technology and signal processing. Just take a look around!

Address:
http://zone.ni.com/zone/jsp/zone.jsp

AVX

This company is mainly involved with capacitors of every kind, but it also handles inductances and couplers. Consequently, microwave technology is well represented. The site contains a huge number of documents, but there are also Spice model collections and the like.

Address:
http://www.avxcorp.com/SpiApps/default.asp

Datasheetarchive and Alldatasheet

Anyone looking for the data sheet for any semi-conductor component or IC should start the search with these two sites. You'd certainly have trouble finding a site where things are made so easy.

Address:
http://www.datasheetarchive.com/datasheet/pdf/3615.html
http://www.alldatasheet.com/

Spice Model Resources

The name says it all: this is where to start your search if you need Spice models for a specific component.

Address:
http://www.emwonder.com/spicemodels/

Internet Treasure Trove article links from VHF Communications 1/2006

SPICE simulators

For anyone who might want to download the most important current SPICE programs on the market and compare them, this is the right place.

Address:
http://www.web-ee.com/Downloads/Simulator/simulation.htm

HF-Fax

That sounds so simple, but it conceals a comprehensive homepage providing information on an unbelievable number of topics. The whole weather satellite scene seems to be concentrated here. From antennas to technology, everything is discussed and made available here.

Address: http://www.hffax.de/

Linear Technology

The „PSPICE“ article in the last issue clearly aroused great interest and led to quite a lot of E-mails and new leads. One of these was especially interesting: Linear Technology are offering a complete Spice machine on their homepage under the name of „SWITCHER CAD“ for research into DC-DC converter circuits. Fortunately, any other circuit can also be simulated there, and the company boasts that it is „making the most accurate and stable PSPICE version available free of charge“. When we checked up, it became clear that there was a whole lot of interesting stuff waiting to be downloaded here:

“Switcher CAD”  (PSPICE simulator)
“Noise”   ( Program for research into noise in OPV's);
„BodeCAD“ ( Program for drawing up Bode's diagrams)
„FilterCAD“ (Program for research into active filters)
„Spice Models“ (Collection of miscellaneous Spice models)
„The Configurator” (Amplifier design tool)
“LT1568 Filter Design Guide (Designing active filters using the LT1568)

Address:
http://www.linear.com/company/software.jsp

emWONDER / S-Parameter Resources

This unpretentious-looking homepage not only deals with S-parameters and their Internet links, but also handles the integration of SPICE and S-Parameters (...which was touched on recently in the PSPICE article in VHF Reports...). You can go into the subject in even greater detail here, so you shouldn't miss the chance to read about the „S-parameter to SPICE model converter“.

Address:
http://www.emwonder.com/sparameters/

Cougar

The company used to be called „Teledyne“ and is no doubt still familiar under this name to many microwave specialists. But the new name has clearly been good for the firm, and there is much to discover on the new website. In addition to application notes, there are naturally some data sheets, but there are also some interesting conversion tables.

Address:
http://www.cougarcorp.com/index1.asp

Watkins Johnson

There are some very active companies whose sites should be visited regularly to see what's new. Watkins Johnson is among them, and the application notes and technical notes are first class. Plus the technical archive has been expanded, and you can now call up almost all the elderly but very well written documents, as they have been made available in scanned-in form (it's unbelievable: right back to 1974!).

Address:
http://www.wjcommunications.com/technotes/index.asp

Mentor Graphics / IC Nanometer Design

For some reason, people tend to associate this company more with computer technology, but, thanks to the WLAN and Bluetooth standards, RF technology is now also appearing everywhere. So what we have here  (under the heading „Physical Verification") is a whole collection of successfully completed circuit simulations. Well hidden, it's true, but worth hunting for...

Address:
http://www.mentor.com/products/ic_nanometer_design/techpubs/index_noflash.cfm?v=google&p=adwords_broad_rf transistor&s=1x1&g=ic&c=ic_ocid_263_cfp_67_ceid_3-1x1-

Useful links from electronics

Here's a Hungarian homepage which, with great attention to detail, brings together countless links relating to miscellaneous aspects of electronics. Just call something up and see whether there's anything interesting here for you!

Internet Treasure Trove article links from VHF Communications 2/2006

AVAGO

This is a new name to learn and get accustomed to looking at their home page from time to time. Following the change from Hewlett Packard to Agilent there have been more changes making a completely separate company for all semiconductor activities. It will take time to get accustomed to the new homepage until you find familiar things (Application Notes, data sheets etc.).

Address: http://www.avagotech.com/

OH2AUE

Right at the top of Finland there are some people who are unbelievably active on the microwave bands and are not frighten of anything (EME attempts soon). Looking around the homepage of Michael Fletcher you have to ask yourself, when did he learn all this and when does he build it all. Respect!

Address: http://www.kolumbus.fi/michael.fletcher/ index.html

Tonne of software

The personal site of James A. Tonne. It offers some interesting filter and antenna programs, these are partly for downloading and partly interactive versions.

Address: http://tonnesoftware.com/

ON-Semiconductors

This is a joy for anyone who works with PSPICE and will probably be repeatedly visited. It offers thousands of SPICE models for all components and not just “standard Spice” versions. Also modern things are to be found such as “ILIB, IsSPICE, OrCAD template “and other exotic things. These can be found very simply using the desired keyword in the search machine.

Address: http://www.onsemi.com/PowerSolutions/ supportDoc.do? type=models&category =503

MMT

MMT stands for Millimetre Wave Technology Group. A surprising insight into where modern technology is going. There are; ideas, still crazier production technology for unbelievable things. Simply interesting to spend some time browsing

Address: http://www.mmt.rl.ac.uk/projects/mrffe/mrffe.html

Matjaz Vidmar

For readers of VHF Communications Magazine, Matjaz Vidmar, S53MV, is well known. Many of his interesting articles have been published over the last few years. He is a professor in Slovenia and has an enthusiasm for technology. His projects are very interesting and worth looking at again.

Address: http://www.ljudmila.org/hamradio/notune.html

TINA-TI

The free simulation software TINA-TI from Texas Instruments: TINA is an easy-to-use, but powerful, circuit simulation program based on a SPICE engine. TINA-TI™ is a fully functional version of TINA, loaded with a library of TI macromodels plus passive and active models. TINA-TI is limited to circuits with two ICs and up to 20 additional nodes.

Address: www.ti.com/tina-ti

Filter pro

The program “filter pro” is an active filter design program from Texas Instruments and is described by them:

FilterPro™ Multiple Feedback (MFB) and Sallen-Key Design Program is a Windows application. This application designs MFB and Sallen-Key low-pass and high-pass filters using Voltage Feedback Op Amps, resistors and capacitors. It also supports a fully-differential version of the MFB circuit. This program includes Bessell, Butterworth, Chebychev, and linear phase filter types and can be used to design filters from 1 to 10 poles. The capacitor values in each stage can be either selected by the computer or entered by the designer. An "always on" prompt window provides context-sensitive help information to the user. The response of the filter is displayed on a graph, showing gain, phase and group delay over frequency.

Address: http://focus.ti.com/docs/toolsw/folders/print/filterpro.html

TPS40K

The program “TPS40K - designers software” is power supply design program from Texas Instruments and is described by them:

The TPS40K Designer software provides a simple design tool for both novice and experienced power supply designers using the Texas Instruments TPS40xxx family of controllers. The software includes advanced analysis tools for the experienced designer to do worst-case loop response analysis and component characterisation. A customisable component database is included. It allows the user to add or remove parts to any of the TI Designer series of power supply software (including SWIFT Designer, V3.3 or Higher).

Internet Treasure Trove article links from VHF Communications 3/2006

ASI (Advanced Semiconductor)

The speciality of this company is the manufacture of microwave transistors and diodes. The web site has data sheets available under the Downloads and Resources headings, a fantastic find!

Address: http://www.advancedsemiconductor.com/

SM5BSZ Home Page - Equipment for VHF DX

This is a simple homepage of the Swedish radio amateur, Leif Asbrink, SM5BSZ, who is a reader of the German version of the magazine, UKW Berichte. His web site has many interesting topics that are easy to access..

Address: http://www.sm5bsz.com/index.htm

List of Semiconductor Manufacturers

A very useful list from Digchip. For anyone looking for the web site of a semiconductor manufacturer, this is an alphabetic list of semiconductor manufacturers worldwide.

Once you have found the web site you can browse at your leisure.

Address: http://www.digchip.com/datasheets/manufactures.php

Flomerics

There are a great many EM-simulators for microwave circuits and microwave antennas. One cannot buy or test every program, therefore it is interesting to search for simulation examples and successfully projects to learn from their experiences. This web site has some interesting examples from established technical publications.

Address: http://www.flomerics.com/microstripes/technical_papers/index.jsp

Caltech University

It is often difficult to find interesting articles and publications from large companies or universities. Because Caltech University is well know from the publication of the microwave CAD software PUUF, it promises a good source of articles. This page contains a complete collection of microwave publications from students and lecturers.

Address: http://www.its.caltech.edu/~mmic/reshpubindex/papers/

INTEL Technical journal

Who would expect PC development to have anything to do with RF technology, so you would probably not search here. But because of the rapid expansion of WLAN technology, INTEL does cover this topic. You can find fundamental or trailblazing articles about applications in the GHz range in the regular Technical Journal.

Address: http://developer.intel.com/technology/itj/index.htm

University of Calgary

Homepages of universities are often a treasure chest for interesting publications. That applies to this Canadian web site.

Address: http://www.atips.ca/groups/rfic

Circuit Sage

It is simply joyful to browse in this extensive library. On this web site you can find basic articles, interesting Application Notes, many technical documents and many other interesting things.

Address: http://www.circuitsage.com/

Odysseus

This web site is a secret store of articles and tutorials on RF technology., particularly to the area of RFIC. They are very well presented even if you sometimes have to search for things. First class!

Address: http://www.odyseus.nildram.co.uk/

Internet Treasure Trove article links from VHF Communications 4/2006

Microwave Antenna Book

For anyone who wants to understand the field of microwave antennas, this has all of the basic information. It is a complete textbook with individual chapters downloadable as pdf files. Very well produced, very informative and kept up to date with many revisions. Recommended!

Address: http://www.qsl.net/n1bwt/contents.htm

Prosig

This site covers the topic “digital signal processing and digital signal processors “. This includes interesting and free of charge tutorials and Application Notes for applications in the audio range.

Address: http://www.prosig.com/signal-processing/

L.B. Cebik, W4RNL

An interesting site for antenna enthusiasts. There is a lot of information on the site plus downloadable information, including a comprehensive history of antennas but the emphasis is on modern technology, in all variations.

Address: http://www.cebik.com/radio.html

University of Idaho

Universities usually specialised in certain areas, in Idaho there is “a centre for Advanced Electronics and Biomedical Research”. The “NASA symposium on VLSI Design” takes place at the university, afterwards interesting contributions or article are made available free of charge as pdf files. There are things like “A 1.2V 2.4GHz Integrated Direct Downconversion Receiver front-ends” or “Design of a CMOS Low Noise Amplifier (LNA) for 5.8 GHz” to read, and many other topics…

Address: http://www.cambr.uidaho.edu/symposiums/

Antenna software

This homepage gives many useful links to antenna design and calculation software.

Address: http://www.ac6v.com/antsoftware.htm

Applied Computational Sciences

Computer simulation of microwave circuits is indispensable for modern design work. This site has some beautiful and detailed examples on LNA design for minimum noise or improved adjustment. They are worth reading, even if you do not use the LINC2 design program used in these examples.

Address:  http://www.rfcircuitdesign.com/

Down East Microwave

Down East Microwave are a rare company, they not only publish a picture of the finished component and the technical data but also a photo of the PCB as well as a circuit diagram. Interesting for own work! The example is a low noise amplifier but the full catalogue has much of interest.

Example LNA article Address: http://www.downeastmicrowave.com/PDF/915lna.PDF

Full catalogue Address:  http://www.downeastmicrowave.com/Catalog.htm

IST

Institute for the Telecommunications Sciences, offers a large selection of information on a wide range of different topics. Worth reading!

Address: http://www.its.bldrdoc.gov/pub/pubs.php

Internet Treasure Trove article links from VHF Communications 1/2007

MuRata

A very well known Far East company famous for coils, capacitors, filter etc. There are not only the product specifications, but also the collection at S-parameter files to the Download. The documentations with the measuring conditions are worth reading with the S-parameter files for separate frequency ranges.

Addresses:

a. homepage: http://www.murata-europe.com/

b. S-parameter collection: http://www.murata.co.jp/sparameter/index.html

c. Measurement of the S-parameters: http://www.murata.co.jp/sparameter/measure.html

University of Guelph (Canada)

One finds interesting things again and again at universities - one must search very thoroughly with them. On this homepage there is a tremendous collection at electronic hobby circuits. Just as interesting however there are links to a data sheet collections, SMD code, etc.

Address: http://www.uoguelph.ca/~antoon/circ/ circuits.htm

Eesoft - Agilent

This simulator is the “Rolls Royce” of RF circuit simulation - both from the price, as well as the extent and the possibilities. Nevertheless the search is worthwhile because the non Rolls Royce content. Here there are introductions or Application Notes for the simulation of different RF and microwave circuits. Also most can be used with little trouble for other cars (Pardon: Simulation programs). A really interesting site.

Address: http://eesof.tm.agilent.com/applications/

Helix Antenna Design and Construction detail

Who is interested in this type of antenna or would like to experiment. Here is a beautiful empirical report on this topic.

Address: http://www.jcoppens.com/ant/helix/index.en.php

At experimental 10Mbit/sec Microwave Data Link

This project takes some time to appreciate, besides the empirical reports and/or results of measurement of the completed project, there are the planning documents, the initial considerations and the PCB layouts etc.

Unbelievably accurately and the last detail inside documents; even the views for RF security and the protection of systems are there.

Address: http://www.qsl.net/ke5fx/uwave.html

RALTRON

Some on-line computations among other things converting SSB phase noise to jitter are to be found with RALTRON. Also the application for quartz crystal jitter and noise are worth reading.

Address: http://www.raltron.com/cust/tools/default.asp

Internet Treasure Trove article links from VHF Communications 2/2007

MicroStripes

This is not individual strip line simulator but a matured 3D simulation software package for draft layout and simulation of microwave modules and antennas

Address: http://www.microstripes.com

Microwaves101.com

An interesting and humorous collection information about “Microwaves”. The operators of the site stress that not everything is fully developed, but it can be used! The site is well designed with many alphabetically sorted articles, topics, Application Notes and software. It is a wealth of information.

Address: http://www.microwaves101.com

Azimuth

This is a young American company offering software test suites for the wireless communications.

Address: http://www.azimuthsystems.com

Internet Treasure Trove article links from VHF Communications 3/2007

Caltech University

A name that everyone should recognise because they produced the PUFF microwave CAD software. Naturally there is a lot of knowledge behind this and they have a collection of interesting RF and microwave documents in a data base stored here…

Address: http://www.its.caltech.edu/~mmic/reshpubindex/papers/p-index2.htm

HP8410

For anyone who develops microwave circuits, a vector network analyser is an essential but expensive part of the workshop. Despite it’s age the HP8410 does the job very well if used with care. It is easy to repair and documents are readily available. Here is a small selection of Internet addresses with interesting information:

http://bama.edebris.com/manuals/

http://www.caip.rutgers.edu/~kahrs/testeq/NA.html

http://perso.orange.fr/jf.fourcadier/hyperfrequences/HP8410/analyseur.htm

http://www.pacificsites.com/~brooke/MWTE.shtml

RFDESIGN

This is a magazine that publishes articles about “RF and Microwave Technology for Design Engineers”. Articles range from software for VLF to the millimetre wavelengths and from the RFIC Design to complete radios. The articles are excellent and available to be downloaded from:

Address:  http://rfdesign.com/

Bama

This site is mentioned in the section on the HP8410 but it is an excellent site for any manuals

Address: http://bama.edebris.com/manuals/

Agilent Interactive Impedance Matching Model

There is something beautiful about playing on a computer with RF circuit design. An introduction to the problems and methods of interactive software with detailed exercises can be downloaded in the famous HP Application note 95-1.

Address: http://cp.literature.agilent.com/litweb/pdf/5952-1130.pdf

SiGe

Semiconductor manufacturers are an important source of information to learn about the latest technologies. This manufacturer is no exception with details of wireless LAN, Bluetooth, GPS and microwave semiconductors. There are datasheets and application notes.

Address: http://www.sige.com/support/datasheets.html

Freeantennas

Here is something for the microwave antenna enthusiast. Many designs are shown with simulated radiation patterns. These include the “Pringle” antenna made from an empty Pringle box.

Address: http://www.freeantennas.com/2400/

Plextex

Plextek is one of the largest independent electronics design consultancies in Europe. Their web site contains a large collection of technical papers on tecchnology for the GHz range.

Address: http://www.plextek.co.uk/technicalpapers.htm

Internet Treasure Trove article links from VHF Communications 4/2007

Microwaves & RF

This is an RF magazine with interesting articles and the occasional review. The “White Paper” and other documents are worth registration.

Address: http://www.mwrf.com/

Design Tools

The Linear Technology web site is always worth a look . Under the Design Support section there are Application Notes and support. There is also a section for Design Simulation that contains a range of software.

 Address: http://www.linear.com/

Circuit simulator “Qucs”

This is an open source circuit simulator with the nice name “Qucs”; it stands for Quite Universal Circuit Simulator. The simulation tool is still being developed but should be no competition for PUFF but is an alternative with som potential.

Address: http://sourceforge.net/projects/qucs

The four metres web site

This site has all you want to know about the four metre band. This is becoming more available as the band II TV stations are switched off in favour of the digital channels.

Address: http://www.70mhz.org/history_g5um.htm

Echolink

This site has a introduction to Echolink the new digital mode for radio amateurs. There are some rigs being produced now with Echolink facilities so it is as well to know what it is all about.

Address: http://www.g3vfp.org/interlink.html

ADT-200

The ADT-200 is an all-digital transceiver designed using the principles of a software defined radio (SDR). The only exceptions to digital components are the preselector and the transmitter output stage that uses high voltage MOSFETs. It was developed by the Swiss amateur Hans Zahnd, HB9CBU and is probably the world wide first all digital amateur transceiver to work independently (no PC!).

The ADT-200 has four independent receivers and eight internal VFOs for many split frequency options. Only three rotary controls and 18 keys switches are used to operate the transceiver. All relevant information appears on two high visibility displays. There are options for 2m or 70cm modules.

Internet Treasure Trove article links from VHF Communications 1/2008

TutorialsWeb

The name says everything: tutorials are collected here and the topics are so varied that a thorough search is worthwhile. You will find some very useful topics covered that will be extremely useful. The scope of the topics will not be revealed here by suffice to say that the web site is well worth visiting.

 Address: http://www.tutorialsweb.com/index.html

Noise and Noise Figure Measurement

A very good detailed homepage. This is nearly a complete textbook online. Great fun to read either for the first time or to refresh knowledge from the past.

Address: http://www.rose-hulman.edu/~black/Noise/ppframe.htm

Propagation Tutorial

A very well presented and easy to read tutorial with plenty of information on antennas, wave equations, propagations, reflections, Noise….?

Address: http://www.mike-willis.com/Tutorial/PF13.htm

BesserNet

You will find many application notes here suitable for the experienced developer or the experimenter. Pleas sepne some quiet time to go through the appropriate pdf documents or download them to read later.

Address: http://www.bessernet.com/jobAids/resourcesAlpha.asp?Type=1

Agilent

No introduction is needed to this company formerly known to us as Hewlett Packard. The company is still growing and to emphasise that there are (on 1 September 2007) exactly 2946 application notes available to download on this homepage. For those who are interested of do not believe this, visit:

 Address: http://www.home.agilent.com/agilent/facet.jspx?lc=eng&cc=US&t=80030.k.1

Designing Antenna systems with maximum sensitivity

This is a very well presented and informative homepage. There are many interesting subjects mentioned on the homepage.

 Address: http://www.pentodepress.com/receiving/receiving.html

COMM Design - Design of center

This is a collection of useful articles and training material from different companies. You will find lots of useful information here.

Address: http://www.commsdesign.com/dcenters/wireless/

Cisco - Carrier to Noise ratio in Cable network

Companies like Cisco who have their roots in computer and network technology make good tutorials on RF and communications available. A good example is this analysis signal to noise ratio. There is more information on this web site, so explore the home page.

Address: http://www.cisco.com/en/US/products/hw/cable/ps2211/products_white_paper0900aecd800fc94c.shtml#wp9000208 

Fast pdf reader

An alternative to the well-known pdf reader is the very small (only 2.1Mb download) and quick software FOXIT reader from the company FOXIT software.

Apart from the free Windows version there is a versions for mobile devices, desktop Linux and U3.

This is worth a look:

Address: http://www.foxitsoftware.com/pdf/rd_intro.php

Satori Technology high dynamic range USB 26.5GHz power meters

Field pioneers Satori Technology have extended their product range of USB power meters with the release of the ST265. This pushes the frequency limit for high dynamic range USB power meters up to 26.5GHz going beyond what is currently available in the marketplace. The ST265 now covers a frequency range of 10 MHz to 26.5 GHz.

The ST series are complete miniature RF & microwave power meters. All measurement data and settings are sent via a USB interface to and from a PC or laptop. This gives the concept of using a computer as the user interface in classic microwave power measurement. Each power meters contains a CPU which controls the sensor, processes the measurement results and operates the USB interface.

The ST265 is a significant enhancement to the existing series (ST124 and ST185 USB Power Meters) and brings with it greatly improved performance. Extended individual calibration procedures have resulted in improved temperature compensation and better linearity performance with RF frequency. The use of a K-type^TM RF connector gives repeatedly low reflection coefficients up to 26.5GHz.

Satori Technology supplies its own easy to use software toolkit which is powerful, flexible and enables multiple power meters to be operated simultaneously. Drivers are available for Agilent VEE^TM and National Instruments LabVIEW^TM. With a size of only 34 x 43 x 125 mm and weighing in at only 83g the ST range of power meters are the ultimate in portability as well as saving space and reducing costs in rack-mounted systems.

Internet Treasure Trove article links from VHF Communications 2/2008

Orban Microwave

There are several interesting Application Notes for microwave and antenna enthusiasts: e.g. Basics of antenna arrays, Basics of patch antennas, An introduction to GPS patch antennas, An introduction to GPS low noise amplifiers etc.

Address: http://www.orbanmicrowave.com/appnotes.htm

100GHz Subharmonic mixer

Those who are interested in the current state of high frequency mixer development should look at this publication. It is very informatively, easy to understand but nevertheless very accurately. A good article like this looks good and extends your knowledge.

Address: http://www.eecs.umich.edu/rebeiz/Completed Research Papers/W_Band_Subharmonic_Mixer97.pdf

Professor Randy Katz

If you type the topics noise, modulation, propagation etc into a search engine you will inevitably encounter the name professor Randy Katz. Such lecturers are a genuine advantage to a university.

As an example, on this web page follow the link “Courses” on the left. In “Course 294.S96” you will find interesting pdf files with extremely good discussion on fundamentals. Also try other searches!

Address: http://bnrg.eecs.berkeley.edu/~randy/

LNA Design for CDMA front ends

This is a ery beautiful and detailed application note about LNA Design from Philips. It accurately describes operating point stabilisation and signal to noise ratio adjustment. A joy to read.

Address: http://www.nxp.com/acrobat_download/other/discretes/CDMA_LNA_design.pdf

Design of a CMOS LNA for 5.8GHz and its sensitivity analysis

Not everything that has been learned in the past is wasted. The good old cascode circuit has appeared in the newest and most modern integrated circuits on a chip… Fundamentals in new form for the GHz range.

Address:  http://www.cambr.uidaho.edu/symposiums/symp11/XuezhenWangPaper.pdf

Antenna Design software and Electrical engineering software - mostly free

This is a good place to find ideas. Everything downloaded and examined was found to be worthwhile and worth spending time to understand

Address: http://www.rfcascade.com/antenna.html

Electric Waves and Antennas

This is a fine thing: someone has written a beautiful book with 21 chapters at present on this topic. It has be put on the Internet for eveluation

Address: http://www.ece.rutgers.edu/~orfanidi/ewa/

Microwave Antenna Design Calculator Download

This Calculator makes the design of a microwave antenna a joy and is easy to understand. You must register first, but the software is really worth it.

Internet Treasure Trove article links from VHF Communications 3/2008

Skyworks Solution

This web site has many items to browse or download. There are detailed documents and application notes on components and modules for microwave engineering. To access these quickly choose the sub menu “Technical library “.

Address: http://www.skyworksinc.com/products_literature.asp

IMEC

The introduction to this site says: IMEC is Europe's leading independent research center in the field of micro and nanoelectronics, nanotechnology, enabling design methods and technologies for ICT systems. This site has much of interest including information on Software Defined Radio (SDR) and a Direct Conversion Receiver for 5 GHz.

Address: http://www2.imec.be/wireless/zero-if/

Radio telescope Effelsberg

For anyone who wants to know about the concepts used for extremely low-noise receivers between 400MHz and 100GHz, take a look at this homepage. The information is sorted by frequency range with ne document per receiver and the associated antennas. Radio telescopes work at the physical limit of receiver technology and it is interesting to study how they move closer and closer to these limits.

Address: http://www.mpifr-bonn.mpg.de/div/effelsberg/receivers/receiver.html

National Semiconductors school of analogue design

That is a great site for almost all areas of analogue techniques including: operation amplifiers, mixer, DC to DC converters… Please look at the on-line courses, in particular the wireless topics.

Address: http://www.national.com/AU/

CMOS Self Mixing Free front end for Direct Conversion Applications

 This publication from University of Hong Kong has good presentation and accurate information.

 Address: http://www.ee.ust.hk/~eezzf/download/frontend_iscas01.pdf

A simple printed broadband antenna

This is an informative and clearly written article on microstrip antennas with good suggestions on this topic.

Address: http://ceta.mit.edu/pier/pier60/07.0509263.Gao.S.pdf

Terabeam HXI

Sounds like Science Fiction, it is however a company who specialise in millimetre wave systems and components. Beside documents on their products there are interesting applications. For example: Frequency Multiplier Application Notes and Gunn Oscillator Application Notes.

Address: http://www.terabeam-hxi.com/prodserve/notes.php

Universitiy of Berkeley California

It is always interesting to search the pages of universities. This homepage has many interesting topics.

Address: http://kabuki.eecs.berkeley.edu/papers.html#rf

Embedded Antennas get the signal

This is a strange title but it is a very interesting article. It describes the theoretical background and the production technology of this new technique.

Address: http://www.edn.com/contents/images/236435.pdf

RF Avenue

This site is a joy to visit, it has an unbelievable array of topics for developers. The heading “RF and Microwave Resources” says it all.

Address: http://www.newwaveinstruments.com/resources/rf_microwave_resources/digital_wireless_communication_directory.htm

Philips RF manual

It is a good idea to put a manual on the design basics for RF circuits on the Internet. This is an excellent document containing lots of useful information.

Address: http://www.nxp.com/acrobat_ download/other/discretes/philips_rf_manual_3rd_edition.pdf

QTH Viewer for Google Earth

Daerek Milka, SP6NVK has produced a QTH Locator Square overlay for Google Earth. Using the link below select “QTH Locators viewer” to download the .kmz file. When this is used for the first time with Google Earth it produces an overlay of the main QTH locator square over the globe. Under “My Places” there are three check boxes to control the overlay. A tick in the subdivisions check box will generate subdivision squares.

Address: http://www.hamatlas.eu/Gg/KML_en.htm

Ecoflex coax cable

For those in the UK the low loss coax cables from SSB electronics can be purchased from Diode Electronics. There is a range of cables in the Aircell, Ecoflex and Aircom ranges. Ecoflex 15 offers 9.8dB/100m loss at 1GHz with a maximum frequency of 6GHz, Aircom plus offers 13.4dB/100m at 1GHz with a maximum frequency of 12GHz.

Address: http://www.diodecomms.co.uk/

G8PUT Logbook Project

With perfect timing the G8PUT logbook project was started just after the use of a logbook by UK radio amateurs had been made optional.   The G8PUT Logbook, Contest and Award System is a computerised Logbook designed to look and feel like a real logbook.  Having been available as a trial version for some time now, the first full release is available from the beginning of 2009.

Designed for quick and easy use with easy entry of QSO details into a screen that looks just like a page in a log book. 

To enter a single QSO can take just 2 more key presses than there are letters in the callsign!

It allows for multiple contacts to remain open when operating in a Net. Single stations can be logged out individually, or the whole Net closed at the press of a button.

Including a rapid entry screen for contest working, and an ever growing number of contests and awards.

Whist the full version of the G8PUT Log Book is now available, the list of features and functions will continue to grow for the foreseeable future.  A list of ideas and extra function requested by users has formed the basis of the programs development and will continue to do so.

The program is available at www.g8put.com, for information email g8put@g8put.com

Internet Treasure Trove article links from VHF Communications 4/2008

Links to SPICE simulation resources

Anyone who has changed to simulate a circuit before it is constructed should look at this site. It gives links to sites with free SPICE models, training courses, software, magazine articles and application notes etc.

Address: http://www.penzar.com/links.htm

VOACAP Quick Guide

“HF Ionospheric Communications Propagation Analysis and Prediction “ this is a wave forecasting and propagation prediction program. It gives information on the current conditions and a free software download.

Address: http://voacap.com/

Watkins Johnson Historical information

For those who are interested in the products manufactured by the well known companies Watkins Johnson or Communications Engineering, this site gives a good overview of their history and products. There are manuals and information on items that you may still find in your shack.

Address: http://watkins-johnson.terryo.org/

Various Scans of HP manual, etc.

If you are like the author always looking for manuals on measuring instruments, this site will be invaluable to find that special manual.

Address: http://www.kennethkuhn.com/hpmuseum/scans/

Keiths Vintage RACAL Enthusiasts Site

This is a site that will bring back memories for the older generation and inform the younger readers. In particular the  RA17 was a milestone in short wave receivers design with its special mixing technique. Now that the analogue receiver is fast disappearing in favour of the SDR receiver the achievements of the pioneers should not be forgotten.

 Address: http://www.recelectronics.demon.co.uk/

NEC LNAs for 2,4 GHz

There are lots of integrated LNA ICs available but this application note is interesting. There is an optimised circuit for a special application (wireless video camera) with information on using the IC and information on prototype. The results of measurement, the circuit and a photographs of the PCBs are published without restriction and therefore are most interesting for the circuit developer.

Address: http://www.valontechnology.com/images/NEC_NE34018_113012LNA_report.PDF

An 18 to 40GHz double balanced mixer MMIC

How do you build a passive mixer for 20 to 40GHz? This question is not only answered in this article with measurement results, but it also gives the reasons for certain technologies used and circuit details. Very informatively.

Address: http://www.plextek.co.uk/papers/BB Pass Mixer Full Paper2.pdf

But this article is not the only interesting item, at the address: http://www.plextek.com/technicalpapers.htm there is a complete collection of technical papers from this company e.g. Oscillator Design, RF mixer Design, Synthesiser Design.

Mini Circuits Application Notes

The information from this company is always very high quality and the application notes are exceptional. Thye have all the information required including a special mixture from basics, characteristics and applications. A very good site with a nice clean look.

Address: http://www.minicircuits.com/pages/app_notes.html

Hittite

The products from this company cannot be ignored. They are an RF and microwave specialist and supply an almost infinite number of interesting products. They have a lot of information on the Internet This site has many interesting items in the literature section such as a PLL calculator and a mixer track calculator, available under the heading “engineering tools”.

Address: http://www.hittite.com/literature/featured-articles.html

Internet Treasure Trove article links from VHF Communications 1/2009

Vivaldi Antenna for Snow radar

A really interesting project and a good article with lots of basic information for this type of antenna its characteristics and applications. Not only for antenna specialists.

Address: http://www.ittc.ku.edu/research/thesis/documents/ravi_prakash_rajaraman_thesis.pdf

Digitally signal processing Tutorial

This tutorial is for anyone who wants to read detailed information about modern technology. This is a pleasant read for an introduction to this subject. There is also a Java applet with information on topics such as FFT principles and designing digital filters or DTMF generators.

Address: http://www.dsptutor.freeuk.com/

Tonne software

This is for lovers of modern software used in our hobby. Everything is here from antenna design to filter design, PLL calculation and some Application Notes.

Address: http://tonnesoftware.com/

EE Times Europe

You should visit this homepage regularly. Again and again there are interesting articles, particularly on the forefront of technical developments. An example is the article: “Using high-spees A/D converters beyond baseband frequencies”.

Address: http://www.eetimes.eu/201804147

TechOnline

An interesting technical site with clearly divided topic areas and many useful things.  There should be no fear of the registration with your own personal data; this gives access to a large amount of interesting documents.

Address: http://www.techonline.com/

24GHz

For those for who become bored with conventional RF technology or become over courageous or who simply look for new electronic challenges, why not try the 24GHz microwave band. This homepage is the best way because there is concentrated information on the topic.

Address: http://www.kielnet.net/home/j.schaefer/atv_24ghz.htm

Texas Instruments

For the big players in the electronics industry communications is important. The frequency ranges are getting higher with ever more interesting and low priced components to stimulate your fantasies.

This applies to the “RF/IF and ZigBee Solutions” from this company. The page addressed below will stimulate your interest. What could you use it for? A further search of the homepage shows possible uses in the amateur radio range.

Address: http://www.ti.com/corp/docs/landing/cc2591/index-google.htm?CMP=KNCreprisegooglehpa&HBX_PK=HPA_2-4GHZ+2.4GHz&HBX_OU=50

Matjaz Vidmar, S53MV

Readers of VHF Communications Magazine should know this name very well because of the developments and projects that have been published.

There seems to be no end to the new projects that come from Matjaz, probably something to do with his job as a university professor. Take the time to look at his latest activities.

Address: http://lea.hamradio.si/~s53mv/zifssb/kband.html

Aerocomm Antenna Tutorial

Another antenna topic, but this time a general tutorial. This is not only for the specialists but for revision and to test your own knowledge or for filling the gaps in your knowledge.

Address: http://www.aerocomm.com/docs/Antenna_Tutorial.pdf

Allocation of the radio spectrum

It is interesting: to see who uses certain frequencies or what frequencies are approved for which services. There are some unscrupulous people who make a lot of trouble.

Address: http://www.jneuhaus.com/fccindex/spectrum.html

144MHz Beacon list

Not of interest to everyone but if you needs it:

Address: http://www.dk3xe.com/b_144.htm

This is only a small part of the interests that this amateur shows the homepage. Please take a further look:.

Address: http://www.dk3xe.com/index3.htm

NASA Tech briefs

A mine of information, white papers etc.. Partially accessible after free registration. The titles whet the appitite.

Address: http://www.techbriefs.com/content/view/3267/34/

Logbook, contest and award system

The Chris Townsend, G8PUT Logbook Project started in late summer 2007, the original idea was to create a simple and easy to use logbook system. Since then he has received many requests to include additional features. The most significant are perhaps Contests and Awards. Work is progressing well on including these and many other features.

The way the project is developing is that new functions and features which have been requested are being added in no particular order. A feature which takes little time to include might be added on the day it is requested. Other features which take a significant amount of work will be made available when they are completed.

Address: http://www.g8put.com/

eBay shop: HamPlace

I came across this eBay shop while trawling for some parts for a new project. The shop has some interesting items at very good prices. Some eBay fans may not want to purchase from Hong Kong but I have had good experiences and in fact the items that I purchase from this shop arrived in 4 working days, much quicker that some major suppliers can manage. – Andy

Address: www.ebay.co.uk - then select shops and enter the shop name

Internet Treasure Trove article links from VHF Communications 2/2009

Microwave101

At first sight the title says nothing. Once you open the site you are greeted with by a complete collection of microwave documents including calculations and information etc. A lot of time is required to investigate everything.

Address: http://www.microwaves101.com/index.cfm

Microwave Detectors

Old things can be interesting and delightful. This information is over 30 years old but has been revised again and again plus presented as an Application Note by Agilent (formerly Hewlett Packard). It concerns the correct use of the detectors 423B and 8470B.

What makes this brochure so useful is the detailed cross section and exploded views of older plug e.g. BNC, N, ApC7 etc as well as the notes on correct handling them and the repair or exchange of such detectors. Some people will also find more memories in this Application Note.

Address: http://cp.literature.agilent.com/litweb/pdf/00423-90103.pdf

Basic Antenna Theory

For those who want to study the basics of antennas at a very scientific level should take a look at this university site.

Address: http://farside.ph.utexas.edu/teaching/jk1/lectures/node81.html

GLOBALSPEC

This site is for those who think they have missed something. It is a high quality engineering search engine that can seek out the maddest things. As an example try the result of this enquiry: Application Notes/Schottky Diodes.

Address: http://application-notes.globalspec.com/Search?query=Schottky Diodes&show=appnotes&frmtrk=ofInterest

OML

For those who find normal RF technology boring, they should take a look at the technology and problems for the frequency range above 50GHz. This homepage has lots of information on measuring instruments and good Application Notes. This is a completely different world.

Address: http://www.omlinc.com/map.htm

Plextek

More and more often manufactures are trying to present information on their new products to their customers and prospective customers. As an example Plextek are introducing a new mixer.

Address: http://www.plextek.co.uk/papers/mixers2.pdf

For those who take a look will find some different and useful things. Click on “Technical Information” on the home page to get a choice between “Technical Paper” and “Downloads”. Selecting Downloads there is a “Smart Antenna Demonstration” that can be downloaded.

Address: http://www.plextek.co.uk/downloads.htm

Amateur radio Astronomy/Western Australia

Radio astronomy always works on the edge of technical possibilities and is therefore worthwhile taking a look for any RF freak. These people begin with low frequencies (see the article on Schumann resonances) and do not stop at 10GHz. All the methods and devices are explained with no secrets. There is also plenty of interest to non astronomers.

Address: http://wavelab.homestead.com/

Ultra Low Power ELF/VLF Receiver Project

Having mentioned Schumann resonances, this continues in the same frequency range. In such receivers the same thought processes and the same technical work is required as in 10GHz project.

This is worth a look and it will inspire your imagination.

Address: http://www-star.stanford.edu/~vlf/ulp_reciv/ulp.htm

Internet Treasure Trove article links from VHF Communications 3/2009

EME

The abbreviation means Earth Moon Earth it is a specialist part of our hobby; QSOs with the moon as reflector. Everything concerned has to be at the forefront of technology and technical know-how because the transmitter powers are limited not much signal arrives at the receiving antenna or the following LNA. This homepage presents the current state of the art information to give an idea of the requirement including the financial ones needed to succeed.

Address: http://www.hb9bbd.ch/index.php3

SETI

Another exotic abbreviation that stands for: Searching for Extraterrestrial Intelligence. This web site has all the information about the many interesting spin aspects; this is sometimes at the edge of physical technology.

Address: http://setiathome.berkeley.edu/

Noise Figure Measurements

For those who art interested in or develop low noise amplifiers the Central States VHF Society has a legue table of the best results achieved each year. It shows what other amateurs have achieved so that you can see how your efforts compare. Studying the lists will cause the genuine developer to think about their own projects.

Address: http://www.csvhfs.org/csvhfnf.html

Microwaves101

For anyone who does not understand a term then this encyclopaedia is the place to look for the answer. There are many things to discover.

Address: http://www.microwaves101.com/encyclopedia/index.cfm

EZNEC Model files

EZNEC is a simulation program for wire antenna simulation in the frequency range up to 1GHz. It can save many unnecessary prototypes and tests. The program does not give complete building and assembly instruction, but the simulation results are so good that usually only fine adjustments are necessary. EZNEC is a good low cost entry into simulation. To save re-inventing the wheel it is a good idea to look at finished projects. This helps to learn how the software works and secondly and existing project can be adapted. Here is a source of such  small project.

Address: http://www.cal-av.com/2d-40-models.html

Also this site has an interesting offer at the end to download an antenna collection:

http://www.voacap.com/antennas/squeezing-decibels-out-of-dipole/

ADIsimRF

This is a free program from Analog Devices that sounds very mysterious. It enables various components (filters, mixers, amplifiers…) to be connected in cascade to form a complete system. The program can then simulate the overall gain, the noise figure, IP3, P1db etc. To use the program you must be registered.

Address: http://forms.analog.com/form_pages/rfcomms/adisimrf.asp?ref=ASCPR-066

Direct Conversion of Receivers

This is an interesting technology that demands high demands on design and construction. It is always interesting to study and see the solutions that other people have achieved. Here are several interesting examples:

Address: http://kd1jv.qrpradio.com/dcrx/dcrx.HTM

http://www.arrl.org/tis/info/pdf/9208019.pdf

http://www.qsl.net/ik2pii/lf/dcrx136.htm

http://www.njqrp.org/sop/schematic rev b.html

Internet Treasure Trove article links from VHF Communications 4/2009

Pentek

Pentek’s software radio and A/D I/O products are the most comprehensive in the industry. Products available in PMC, PMC/XMC, PCI, PCIe, cPCI and VIM formats

Address: http://www.pentek.com/sftradcentral/SFTRadCntrlPrd.cfm

SAC - EDUCULT: Education, hobby and culture related programs and texts

This site has an amazing list of software, it is displayed a page at a time but unfortunately there is no index. If you are patient you will find such things as the CAD program pcaad.zip to design antennas like log-periodic, patch antennas and the horn radiators.

Address: http://www.sac.sk/files.php?d=4&1=P

Amateur radio links

This is a German site with many useful amateur radio links. Even if you do not speak German there is enough description to find some useful information.

Address: http://www.amateurfunkbasteln.de/download.html

Calculatoregde

This site is a catalogue of free online engineering calculators for engineers and Students worldwide. It features a few hundred calculators for solving complex equations and formulas in the fields of electrical, mechanical, chemical, electronics, civil, metallurgy, oil & gas, optical, plastics, ceramics, physics, maths and many more. The address below points to the electronics section.

Address: http://www.calculatoredge.com/index.htm#electronics

Guided Wave Technology

This site is dedicated to design and analysis of micro and millimetre wave filters from 0.5GHz to above 100GHz

Address: http://www.guidedwavetech.com/wg-choose.htm

There are some very useful links for microwave filter design on their links page

Address: http://www.guidedwavetech.com/Links.htm

Practical RF Circuit Design for decaying Wireless of system

It is unbelievable, but true: this is a 588 page technical book on the Internet - free of charge. It can read on-line or as a pdf file. If you go to the web site, be patient because it takes some time to start displaying the pages.

Address: http://www.scribd.com/doc/7236184/009-PracticaI-RF-Circuit-Design-for-Modern-Wireless-Systems-Volume-II

SynFox

SynFox is a revolutionary very high accuracy, ultra-low noise wide-band RF synthesiser with 1Hz minimum steps, better than -100dBc/Hz @ 1kHz, associated with a few tens of µs lock time. SynFox is suitable for a tremendously large variety of applications programmable from 0 to 3GHz.

Address: http://www.sigfox-system.com/pages/synfox_epag.html

Tin Plate Boxes

Many of the projects published ion this magazine are designed to fit into tin plate boxes. These are nor easy to find in the UK but Alan Melia stock quite a range of these boxes.

Address: http://www.alan.melia.btinternet.co.uk/componen.htm

Internet Treasure Trove article links from VHF Communications 1/2010

NXP

If you do no know; Philips has a new name for its semiconductor activities. Go to this site if you are looking for data sheets, SPICE models, S parameter files or Application Notes for components from this manufacturer.

Address: http://www.nxp.com/#/homepage

Radio Electronics

Sometime homepages are boring but this homepage is full of tutorials ready to download. There is plenty worthwhile browsing here.

A tip: Begins with  the “RF Technology and Design” section.

Address: http://www.radio-electronics.com/info/electronics-tutorials.php

Tutorial on the double balanced mixer

A pdf file hides behind this inconspicuous title that describes this important component in detail and describes all possible applications. It is well worthwhile reading this article.

Address: http://arxiv.org/PS_cache/physics/pdf/0608/0608211v1.pdf

Practical RF circuit design for modern wireless of system

It is unbelievable, but true: this is a 588 side technical book on the Internet - free of charge. It can be read either online or download as a pdf file. That is a mad service.

Address: http://www.scribd.com/doc/7236184/

(009-Practical-RF-Circuit-Design-for-Modern-Wireless-Systems-Volume-II)

PCMag.com

Who would have thought that a PC magazine would offers a whole collection of useful free programs that can be downloaded entitled “Electrical engineering programs”.

Even the DOS antenna design program “pcaad.zip” is available from this site.

Address: http://shareware.pcmag.com/product.php%5Bid%5D45169%5Bcid%5D93%5BSiteID%5Dpcmag

Orban - The Basics of Patch Antennas (Updated)

The original article was first class. It has been updated as a result of much feedback and many letters. So it can confidently be called obligatory reading for all who want to use patch antennas.

Address: http://www.rfglobalnet.com/download.mvc/Technical-Article-The-Basics-Of-Patch-Antenna-0001

Hoverman HDTV UHF antenna

What age does this belong to? In any case curious electronics engineers will want to read this article. Above all there is plenty of history provided. For the ruthless the NEC2 simulation files are also included.

Address: http://www.jedsoft.org/fun/antennas/dtv/gh.html#toc-3

An alternative address: http://www.digitalhome.ca/ota/superantenna/index.htm

The WB0DGF Antenna Site

Since we are already looking at antennas, here are some more. Spend some time to browse through all of the information on offer.

Address: http://wb0dgf.com/

4nec2

The keyword “NEC” is well known for simulation of wire antennas. More precisely: NEC2, because the much improved current version NEC4, cost too much at the moment.

For some years 4nec2 has been at the forefront of design software. Not only because of its beautiful coloured 3D result diagrams and structures, but because it offers almost unbelievable possibilities during design and the optimisation - and it is free! (a friendly amateur made the comparison of the bicycle to the Porsche for the software changes).

Address: http://home.ict.nl/~arivoors/Home.htm

UERJ - Professor Gil Pinheiro

Something from South America (UERJ – Univerity of Rio de Janeiro). A list of some older programs that are still useful today. Even without Portuguese knowledge they have a simply clean-look!

Address: http://www.lee.eng.uerj.br/~gil/circom.html#_Download

VHFDX.net

This site has lots of good information and it costs nothing. Plenty to interest everyone.

Address: http://www.vhfdx.net/index.html

K1TTT Technical Reference

Again something to investigate and if necessary download.

Address: http://www.k1ttt.net/technote/techref.html

Internet Treasure Trove article links from VHF Communications 2/2010

Ken’s web site

Ken is an accomplished professor from Alamba (a great acknowledgement from Gunthard who is a accomplished professor from Tettnang). This homepage has a wide variety of subjects it is well worth a read

Address: http://www.kennethkuhn.com/

A very high dynamic range LNA for 144MHz

Something for constructors and developers of low-noise preamplifiers. A very well written, detailed and informative magazine article in the pdf format; worth a close look.

Address: http://www.radiowrench.com/sonic/dubusvhfpreamp.pdf

Falstad

It is difficult to imagine how the author has gathered so many articles for this web site. There is a surprise when opening this site: innumerable Java animations (applets) on the most diverse topics from electronics and physics and more to be examined and tried out e.g. the antenna simulation with facilities for varying the parameters. In addition the link list is first class.

Address: http://www.falstad.com/mathphysics.html

Teslamania

From time to time you may need some entertainment (not only by the cinema) or have a view of another world. Therefore you should take a look at this site.

It is about Tesla currents and makes everything look very wild with metre electric arks hissing and sizzling in the air. It is not really relevant to electronic engineers but it is quite interesting.

Address: http://capturedlightning.com/

Spread Spectrum Scene / S Parameter tutorial

This is a favourite site to be visited from time to time. It is regularly extended and reorganised. The author found the following special article while searching for some S Parameter files for a new development. The tutorials are very useful.

Address: http://sss-mag.com/spara.html

Antenna Basics

Again and again it is interesting to read are such introductions, particularly if they are easy to read and understand. In addition this is a visible pdf file - an interesting read.

Address: http://wireless.ictp.it/handbook/C4.pdf

Small Spacecraft Antenna Selection Tutorial

Particularly interesting for lovers of horns; not those used for music make, but those that can radiate and receive microwave signals. This is a good overview with an accurate technical background. This is a fascinating subject.

Address: http://www.antdevco.com/ADC-0807201305 - R0 Small Spacecraft Antenna Selection Tutorial.pdf

How radio Telescopes work

This title does is not completely fair because the contents clearly go beyond that. There is extra information under “Learn more” that is really interesting.

Address: http://www.nrao.edu/index.php/learn/radioastronomy/radiotelescopes

Scanned old books

Many interesting old books have been scanned; among other things the books of Sturley (about receiver engineering) are recommended for the fans of valve technology. According to the site there are about 1043Mb available.

Address: http://www.pmillett.com/tecnical_books_online.htm

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