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Simulators >> RF Simulators >> question about large signal s-parameter
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Message started by danda821 on Jul 12^th, 2005, 1:21pm

Title: question about large signal s-parameter
Post by danda821 on Jul 12^th, 2005, 1:21pm

I am wondering if there is a way to do large-signal s-parameter simulation in cadence. In ADS, you can do the simulaiton using LSSP. Thanks.

Title: Re: question about large signal s-parameter
Post by ssupin-ma on Jul 12^th, 2005, 2:32pm

PSP will do this for you.

(1) Set PSS with input port at the power level that you want
(2) Set PSP with input and output port that you want to check, set the harmonic at input and output at harmonic = 1 (or specified harmonic tone that you would check the S-parameter), set the single sweep frequency at the input frequency (relative 0Hz or Absolute fundamental freq.)
(3) sweep the PSS frequency can cover the frequency that you want to check.

Under some condition, you can keep the PSS frequency and sweep a (small) frequency range under PSP. and still get accuracte results. (but much faster)

Simon ::)

Title: Re: question about large signal s-parameter
Post by Frank Wiedmann on Jul 13^th, 2005, 12:45am

I do not believe that this method will give the correct results if the circuit has significant nonlinearities, see http://www.designers-guide.org/Forum/?board=rfdesign;action=display;num=1082225168;start=4#4.

Title: Re: question about large signal s-parameter
Post by Baolin Yang on Jul 13^th, 2005, 9:43am

ADS's LSSP does harmonic balance and the input port signal is set to one harmonic in simulation, even though the post-processing is similar to PSP.

The harmonic balance simulation has nonlinear effects. So the result is different from PSP. Only if the power level of the input port signal is very low, the result will be very close to that of PSP.