Help me design a wideband VCO 32-110MHz

[liberal]

I want to design a wideband VCO 32-110MHz,Can you give me some examples about HF wideband VCO?Thank you very much

 

[biff44]

Re: VCO design

You have two ways. 1) build two higher frequency oscillators, mix them together, and take the low side IFoutput. One oscillator at 432 to 510 MHz mixing with a fixed 400 oscillator, for instance. or 2) get themost hyperabrupt varactor you can find and get two or three different inductor values to cover the range, and use a PIN diode or fet to switch in the different inductor values.

 

[maddy]

Re: VCO design

We can have a Ring VCO with that kind off tuning range if Phase Noise spec isnt too stringent...

Rgds
Maddy

 

[wjnbry]

Re: VCO design

i remeber rfic had a good example for vco design.
try www.rfic.com

 

[kevinj]

Re: VCO design

It's a VCO with no control at 700MHz. if you change the L on the tank you can tune to lower frequency. Try it.

 

[rfmw]

Re: VCO design

You should be able to cover the range using some parallel hyperabrupt diodes (BB640 for example) without switching the inductances. I've played with such oscillator and it achieved frequency coverage from 77MHz to roughly 300MHz... (BF998 + BB640s were my friends)