Open source alternative for PSS, PAC and Pnoise

[mwb]

Hi, I use Spectre for all my analog design simulations. Unfortunately, I am writing a proposal that requires some simulations and I cannot simulate using Virtuoso/Spectre for legal reasons. I need to simulate an N-Path filter "like" circuit and require PSS, PAC and Pnoise or some alternative that will get me similar results... but like I said, I can't use Virtuoso or Spectre.

I can use ADS though and I'm familiar with ngspice. ADS has a "harmonic balance" simulation framework for its PSS simulations but its not nearly as intuitive as Spectre's. I'm not even sure I can do what I need to do in ADS but it looks promising. Same for ngspice.

Does anyone have any suggestions?

Thanks

 

[BigBoss]

PSS is a property technique of Cadence and nobody can use that without written authorization.
But I'll tell you that HB results are more accurate in my opinion. PSS is not a perfect technique as claimed.

 

[mwb]

PSS just describes an analysis that can be performed using different methods e.g. shooting or HB. ADS has their version of PSS but it only uses HB. I agree that what we all call "PSS" in industry usually means Spectre's but ngspice also does PSS and so does ADS albeit its not as nice.

Maybe I wasn't clear in my original question. I know there are other SW platforms that do this. I'm 90% sure ADS will do it but not exactly sure how. I want to get the noise figure and gain vs. freq of a switched capacitor circuit. This requires PSS. I can run HB (e.g. PSS) in ADS but can't do a small signal AC analysis (e.g. PAC). I can probably run many transients and use MATLAB to calculate the gain and maybe that is the way to go but is there an easier way?