Help - Design a Network Analyzer

RF people,

I am trying to design a Network Analyzer.

Questions :
What detectors?
Analog Devices log amps ?
What signal source?
Use DDS (direct digital synthesis) ?
Use oscilloscope for display?
or computer display?
Or provision for both?
Software ?

Thank you for ANY suggestions


johnseven

Try these links:

http://www.geocities.com/hagtronics/vhf_na/index.html
http://www.qsl.net/n9zia/spec/

I remember reading the article about the Hagtronics in QEX. It is a very clever setup and I think it is the way you should go.

[quote="GaAs FET"]Try these links:

http://www.geocities.com/hagtronics/vhf_na/index.html
http://www.qsl.net/n9zia/spec/

GaAsFET and Toonafishy.
Got 1st part of QEX article reprint. Excellent !.
Thank you.
Next is to get another QEX issue where the same author Hageman, describes
a 250 MHz DDS source to use with the analizer.
Thank you, guys !
j7

look at circuit caller 150 there is a full design up to 1 ghz

bobi

Bobcat1, can you explain me what is circuit caller ?

Thanks

Mandi

For a vector network analyser try here: http://www.geocities.com/NapaValley/4371/

It looks like a good design

hi

i hope my experience in designing a spectrum analayzer can help u

1.For detector u can use a digital filter with dsp and measuring its power after filter
2.For log amp u can use ad8307 that have 80dB dynamic range and DC-500MHz Bandwidth
3.For signal source u can use a DDS or Hybrid PLL-DDS frequency synthesyzer
4.And finally if u use computer for display u can interface with ur DSP from computer easily.

Bests

Bobcat1, Gakusei and Circuit_Seller.

I'm reading and following your many links/suggestions.
Very useful, indeed.
The first quick'n dirty experiment "to get a feel" for the problems, using
Analog Devices's AD8302 works. Good chip with mag and phase detectors,
but with only 60 dB range.
I'll proceed.
Thanks again,

J7

Hi johnseven

I read AD8302 datasheet, but i did not find anythings about its performance below 100MHz.
Do you have expriences in working with it below 100MHz? is it still have good performance?

Regards

Soryy for the delay. I was traveling ...

Yes. It works well in those frequencies too. I tried it as low as 5 MHz and it performed as well as at 100MHz.

there is design at cypress using the PSOC chip .. it was an awarded design .
i got all the parts and never put it together .But is a nice design