RF - VHF and UHF amplifier handbook

You might look at "2014 Handbook," ARRL website.

50 bux softcover, 1320 pages. That's .04$ per page!

=================== You can get nearly any book from

Then just do an Inter Libray Loan request through ANY library.

you will have it in 1-2 weeks.

It's freeeeeeee

Helpful to explore various areas.

jb

The ARRL and RSGB sites should be a good starting point.

For VHF/UHF specific books, the ARRL seem to have dropped my favorites.

RSGB seem to have published the second edition of "VHF/UHF handboook", which might be useful. I haven't seen the second edition, but the first edition was good, but unfortunately badly outdated with lots of tube circuits :-).

Hi,

Thanks for your reply. The book by Andy Barter seems interesting. In fact I have the 2001 ARRL book, a bit old by now but it didnt have what i am looking for,

jozamm

It would be helpful if you would provide some more detail as to what manner of low noise VHF/UHF receive amplifier you're trying to build or design. For example, does VHF/UHF mean the TV bands, ham bands, or commercial 2-way radio bands? Are you planning to cover each band separately, or are you doing a broadband design? Does low noise mean a cheap MMIC, or are you listening to satellites with a cooled GaAsFET or PHEMT amp? Do you have any target specifications such as gain, bandwidth, flatness, dynamic range, IP3 (3rd order IM), power supply,

50/75 ohms, etc? To give you an idea of what's needed and what can be done, I suggest you dive into the MCL amplifier catalogs:

I also suggest you take a 2nd look at the various ARRL book offerings. There are also a substantial number of older designs found in QST and QEX magazines. However, you need to be an ARRL member to view them online.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Hi,

Thanks for your help.

I know quite a fair bit on electronics but I have never attempted high freq uency construction but I am quite knowledgeable on the theoretical side. My target project is the design of wideband low noise amplifiers.

However to start with I want to build some ready made VHF/UHF amplifiers in target range of 50MHz to 650MHz just to get a feel of the construction tec hniques and ideally have some results which I can compare my built circuit with. Consider this some sort of pre-prototyping phase.

Forced cooling is out of the question and I want to minimize the NF of the circuit.

Thanks for your suggesti> On Sat, 14 Jun 2014 06:31:28 -0700 (PDT), jozamm

the VHF and UHF range in a practical manner. I am learning on this subject so if I have some circuits/projects which I can build and test would be ve ry helpful for me.

at i am looking for,

Please understand that you are inviting trouble if the amplifier bandwidth is more than you really need for your signal. An unnecessarily wide band increases the noise and makes an opportunity of undesired signals wreaking havoc with the signal you're interested in, especially if the input comes from Nature (an antenna).

You did not yet tell what signal you're attempting to amplify, and what will the maximum expected input and output signal levels be. It is quite different to sense an NMR signal or a crowded ham band.

--

Tauno Voipio

Are you going to connect this to any appropriate antenna or some miniature, high loss antenna ?

If you really intend to amplify that whole frequency without any filters ahead of the amplifier, you need some strong (high IP3).

For VHF frequencies (below 300 MHz) a 3 dB noise figure is enough, above that, 1 dB amplifier NF might be usable in some cases.

I think Jeff was refering to liquid nitrogen (77 K) or liquid helium (4 K) cooling, not to some fan cooling at room temperatures :-).

I do not see much point in LN2/LHe cooling below 1 GHz.

You would get better help if you would supply:

1. What problem are you trying to solve. A simple statement of purpose is sufficient.
2. What do you have to work with? Test equipment, facilities, abilities, books, parts, etc.
3. What have you done so far and where are you stuck?

The IP address in your header puts you on Malta. Do you have the resources (mostly parts and test equipment) to accomplish this?

Please forgive me for being blunt, but I doubt that. You have not demonstrated the vocabulary and numerical specifics that generally accompanies someone with electronics experience.

Well, the first thing you need is not a design that can be plagiarized, but rather some RF fundamentals and dictionary to explain the terms. You will also need access to some test equipment with which you can measure the NF (noise figure), gain, IP3, and other RF related parameters to determine if your paper design is realizable. One of the nasty problems in RF is that you can have an almost perfect model of a simple amplifier, using nothing but the best components, and still show oscillation, motor boating, excessive noise, etc by simply making a mistake in layout or construction. With low noise, everything has to be right, or it won't work.

Ok, that's fair. The various ARRL books are full of construction projects. Some of them actually work. Most of them have uncorrected typographical errors which offer an additional challenge. 54 to 650 MHz is roughly the US VHF and UHF TV bands. I don't know of any kit for that range because the requirements are minimal and because the availability of very cheap commercial products makes kits unprofitable. However, if you want to start with such a broadband amplifier, it will make a good exercise in layout and bypassing.

I suggest you start with a broadband MMIC amplifier. Something out of the MCL catalog. MCL sells designers kits, which should give you a tolerable start: Included are about 20-30 individual MMIC amplifiers, with varying gains, NF, and IP3 specifications, so you can experiment. The MMIC chips are all 50 or 75 ohm input/output impedances, thus eliminating most of the problem of impedance matching. Most are unconditionally stable, regardless of input/output loading, also making life easier. Be sure to read the amplifier app notes:

After you've blown up a few MMIC devices, you can graduate to a lower noise design using perhaps PHEMT devices:

Wideband MMIC amp:

There are a fair number of articles on the web on RF layout techniques. Goggling for a random sampling: etc...

Everyone has their own favorite way of doing layouts. Mine is put the ground plane on the component side, and connect the wires on the blank circuit side. This has the advantages of providing a very large continuous ground, and allowing the easy translation of the point to point wiring on the component side, to PCB wiring. Mounted on a metal plate, the component side ground sandwiches any RF leaks from the circuit side between two metal shields. (Wires radiate, components radiate less).

You'll soon discover that gain, dynamic range, NF, noise floor, and IP3 are all inter-related. You'll also find that narrow band and broadband amplifiers are very different. For example, a broadband amplifier usually has little in the way of front end selectivity. A strong signal anywhere in the band pass will be amplified, mix with some other received signal, and produce an ugly mess of intermodulation products. The only way to prevent this (without filtering) is to increase IP3, which most often means dissipating more power. Heating is not what you want to keep the NF down. Most of this is covered in the various books on the topic.

Very low noise amplifiers are usually cooled. If you want less than

0.5dB NF at 450 MHz, you'll need to provide some form of cooling. A fan is not enough. At minimum, a Peltier junction and heat sink. At best, liquid Nitrogen. However, for starters, see what you can do without any cooling.

Hint: If you want specific answers and recommendations, your will need to be more specific as to your goals, requirements, and resources. I can't guess what you're trying to build.

Good luck.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Yep. I once bid on doing a cryogenic cell site front end design but lost to someone that had much more experience. I also didn't have all the cryogenic equipment needed to work with superconductive ceramic front end diplexers. Most of what I know about cooling came from researching for the bid.

I did ok with dry ice (frozen CO2) and not so ok with grossly inefficient Peltier junctions. I would put the break point at about

500 MHz, not 1GHz, but otherwise, I agree that cooling works best at microwave frequencies.

Some notes on cooled receiver front ends from SETI:

More:

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

As long as you have the "hot" (300 K) ground in your receiver antenna pattern, there is not much point to use antenna preamps with noise figures below 1 dB.

On the other hand, if you can protect your sky pointing antenna from the ground or Milky Way noise, please go ahead.

On a sunny day (Sun, 15 Jun 2014 16:07:23 -0700) it happened Jeff Liebermann wrote in :

I have a superconductiong cellphone tower frequency filter: Front:

Rf connections: Sterling cooler on table, gets you 70K:

There are many more pictures on that link, look for 'super_filter' Cooler is nice to make your own rocket fuel :-)

Its a vibrating cooler running on about 60.3 Hz from a large PWM amp at 24 V DC. But you can sort of run it on 60 Hz wih a variac (not on 50 Hz), needs to be in mechanical resonance. The filter is made of superconducting material, and quite steep, sits inside this dewar:

Lots of good quality amps too.

Now it is part of my time machine.

Here are some old ARRL and QEX publications that might be of interest

ftp://ftp.ham.hr/Books/