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Simulators >> RF Simulators >> SpectreRF simulate VCO phase noise with divider
https://designers-guide.org/forum/YaBB.pl?num=1200581479

Message started by neoflash on Jan 17^th, 2008, 6:51am

Title: SpectreRF simulate VCO phase noise with divider
Post by neoflash on Jan 17^th, 2008, 6:51am

Since I failed to get reasonable result, from EldoRF, for a cascaded VCO and divider, I turned to spectreRF.

I'm simulating a 5G VCO with a cascaded divider-by-4. I'm probing phase noise at the output of divider.

When I setup the beat frequency as 5G and put probe at VCO output, the pss analysis can not converge. However, when I put the probe at divider output and set beat frequency as 1.25G, the simulation converged with some warning.

I'm not sure whether it is the correct setup. Since spectreRF is more used among people, hope i can get some help. Thanks.

Title: Re: SpectreRF simulate VCO phase noise with divide
Post by Stefan on Jan 17^th, 2008, 6:53am

Put probe output on vco but set beat frequency to 5G / 4 = 1.25G

Slowest frequency in circuit should determine you period for the PSS.

Title: Re: SpectreRF simulate VCO phase noise with divide
Post by neoflash on Jan 18^th, 2008, 1:52am

Yes, thanks.

I found the results are different if I put probe at divider output.