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How to make a VCO-based frequency synthesizer?

How to make a VCO-based frequency synthesizer?

How to make a VCO-based frequency synthesizer?

Could anyone tell me, or give me any references on the basics of how to make a phase-locked VCO-based frequency synthesizer operating at around 2GHz. (would like to be able to tune it from 500MHz - 2GHz, if possible)
I read that it is possible to lock a 2GHz VCO with a 10MHz reference. How is that done??

RE: How to make a VCO-based frequency synthesizer?

The VCO runs at .5 to 2 GHz. It is divided by 2000 to 8000 and this is compared by a phase detector to 10MHz.

Error through loop filter controls VCO.

If you have no experience at HF work, do not expect a working circuit !


RE: How to make a VCO-based frequency synthesizer?

I have some experience on HF circuit. Mainly based on connecting SMA-connectorised devices together, eg Mixer, Amps, Filter, etc. I can't make striplines... Where can I buy such 2000/8000 RF divider that works at 2GHz? Frequency harmonics multiplier is easy, but divider? RF D-type?
Please advice...

RE: How to make a VCO-based frequency synthesizer?

I do not believe you will find a VCO that tunes Two Octaves(500-1000MHz, 1-2GHz). It is tough enough to tune One.

RE: How to make a VCO-based frequency synthesizer?

What I really need now is a 2GHz oscillator which can be fine-tuned in 1KHz (or less if possible) steps for 10MHz or so. I am building a fiber ring laser, with an optical modulator in the cavity. The cavity fundamental frequency is around 3MHz.
Another question is, if I do not need tunability, how can I build a stable 2GHz oscillator cheaply? can any one give me some links to some low cost oscilator? Thanks!

RE: How to make a VCO-based frequency synthesizer?

The company Mini Circuits does a whole range of extremely good VCO's that would suit your purpose, prices are around 50 pounds or so. I use them myself for Radar circuits.

RE: How to make a VCO-based frequency synthesizer?

Synergy makes complete frequency synthesizer packages at these frequencies based on LMX series PLL from National.


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