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Simulators >> Circuit Simulators >> Frequency Sweep with PSS and QPSS
https://designers-guide.org/forum/YaBB.pl?num=1176997787

Message started by Mosieur_Oiso on Apr 19^th, 2007, 8:49am

Title: Frequency Sweep with PSS and QPSS
Post by Mosieur_Oiso on Apr 19^th, 2007, 8:49am

I want to simulate the large signal frequency response of an amplifier.
I use these options in PSS or QPSS: Sweep / Frequency Variable: Yes / Variable Name: frq (frq is my fundamental tone, accessible from the "Select Design Variable" button, so I believe this should be possible), but I always get the sweep to fail.
Can somebody tell me how to sweep the fundamental tone in PSS or QPSS?
Thanks...

Title: Re: Frequency Sweep with PSS and QPSS
Post by Andrew Beckett on Apr 20^th, 2007, 1:52am

There should be no problem with doing this.

With PSS, you need to ensure that the fundamental is consistent with the frequency you're sweeping. If it's a single tone, just put the same variable in the "beat frequency" field. If there are multiple tones, the easiest way is to go to the options form for PSS, and scroll down to the bottom where it says "additional options" and enter "autofund=yes" (this tells spectre to figure out the beat frequency from all the sources in the schematic).

For QPSS it always figures out the frequencies from the sources - so it ought to work.

You didn't say how it failed - so it's very hard to give a precise answer.

Regards,

Andrew.

Title: Re: Frequency Sweep with PSS and QPSS
Post by Mosieur_Oiso on Apr 20^th, 2007, 3:05am

Hi Andrew,
I've put the same frequency variable name in the "Beat Frequency" field and it worked!! :) My mistake was to enable "Auto Calculate", so the Beat Frequency was then a numerical value picked from Analog Design Environment, hence constant for the complete frequency sweep...
Thanks again...
Oiso