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Simulators >> Circuit Simulators >> Sparameters sims does not match AC sims
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Message started by eefet3 on May 1^st, 2014, 3:22pm

Title: Sparameters sims does not match AC sims
Post by eefet3 on May 1^st, 2014, 3:22pm

I had ported a verilogA model for MESFET device into Cadence. I successfully used this model in ADS. I see discrepancies in Sparamters sims vs. AC sims. In ADS I do not have this issue. It seems that in specrtre the gm (re(Y21)) of the device is significantly lower then extracted using AC simulation. In ADS I get identical gms independently of the type of the simulation used.

I am quite confident that I do not have a mistake in my test bench since I am using the same approach on the BSIM model, and AC and Sparam gm matches.

Any ideas? suggestions?

Thanks,
Aleksey

Title: Re: Sparameters sims does not match AC sims
Post by eefet3 on May 5^th, 2014, 2:00pm

Just want to add a little more information and another question. If I run transient simulation as a part of the bench than AC, DC and SPARAM seem to agree. Why would adding transient simulation change outcome of the Sparameters and AC simulations? I always though that are independent simulations.

Am I doing something wrong?