# How to generate a high-frequency clock?

I want to generate a high frequency (4.25 GHz) clock for a high frequency communication circuit. So, my question is:

What are the alternate ways of generating the high frequency clock and which would be the best way out?

Some pointers to components/ICs would also be of great help.

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Stability specs? – Russell McMahon Jan 25 '12 at 13:41
Is this homework / assignment? – Russell McMahon Jan 25 '12 at 14:00
More detail please. Is this homework. If so, tell us what is being asked of you and we will help you learn. – Russell McMahon Jan 25 '12 at 14:07
@RussellMcMahon: No, this is not homework. I am designing a high bandwidth (500 MHz) communication circuit around 4.25 GHz central frequency. I am not sure of stability specs. – Neel Mehta Jan 25 '12 at 14:14

• SAW

Impatt Diode

Gunn Diode

Magnetron / Klystron / TWT

Esaki diode (tunnel diode)

fXo

Fractional N synthesiser.

More ...

For $US35.70/1 on stock you can gete 1 GHZ fxo modules from Digikey here for prices. FXO-PC73 series. Up to 1.35 MHz. Multiply in various ways from there. Datasheet here They say: • EXTREMELY Low Jitter • Low Cost • Frequency Resolution to six decimal places • Stabilities to ± 20 PPM • -20 to +70°C or -40 to +85°C operating temperatures • Serial ID with Comprehensive Traceability For$5/1 you can buy synthesiser ICs that cover your range.
Typical example only

Pricing
Datasheet TI LMX2434

Gunn diode oscialltyors using cavities for fequency tuning and with varactors for tuning are a time honoured solution and may give you power levels that can be used directly.

Gunn XBan - well above your range useful

Ham Radio mag 1980 DIY 10 GHz - very relevant if DIYing here

MUCH more. More detail please. Is this homework. If so, tell us what is being asked of you and we will help you learn.

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 Does the integer-N PLL (which can go upto 64/5) allow locking into any multiples of the oscillator/crystal frequency? or is it just powers of 2 (e.g. 32/33, 64/65, etc)? – Neel Mehta Jan 26 '12 at 6:43 If I use a 50 MHz crystal and a PLL frequency synthesizer like ADF4108, can I generate a 4.25 GHz clock? – Neel Mehta Jan 26 '12 at 7:04