Does anyone have insight into how a VCO with a periodic signal on the control voltage would be simulated with PSS?  The expected spectrum is the vco tone with sidebands on either side at the offset corresponding to the frequency of the varactor control voltage signal.  

Clearly, TRAN and then FFT is one way of doing it, but can it all the done with PSS/QPSS?

Thanks for your help.

Cheers,

Boris