I am running a ring-oscillator with almost sinusoidal voltage output. I am injecting the PAC current at certain point and seeing the PXF result for the oscillator output voltage.
I see the oscillator reaches the steady state after 1 ns.
But, the PXF magnitudes for various sidebands are varying as I change the TSTAB from 2ns to 5 ns.
Can anybody please tell why it is doing so ?
Without seeing it, I can't say (you should contact customer support). There may be something wrong with the setup and it may be reaching false convergence because of that.