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Simulators >> RF Simulators >> cadence problem : IP3 with PWL
https://designers-guide.org/forum/YaBB.pl?num=1384702354

Message started by purplewolf on Nov 17^th, 2013, 7:32am

Title: cadence problem : IP3 with PWL
Post by purplewolf on Nov 17^th, 2013, 7:32am

Hello All/Cadence Support,
I am having the problem figuring out how to run IP3 simulation if the input file is a pwl file. I am easily able to run all other analysis of PSS except the IP3. I have tried PSS+PAC, QPSS which are usual for calculating IP3 but it dont work. For example,with the PSS+PAC analysis the PAC>IPN Curves has the message ''The data for each sideband of the pac analysis contains are frequency sweep.As a result,the above selected function cannot be executed'.
I need urgent help in this regard!

Thanks!

Title: Re: cadence problem : IP3 with PWL
Post by aaron_do on Nov 17^th, 2013, 9:12pm

Hi,

if you are able to plot everything except IP3, why don't you plot the IM3 and fundamental components and then calculate IP3 yourself?

Aaron

Title: Re: cadence problem : IP3 with PWL
Post by purplewolf on Nov 18^th, 2013, 1:29am

Hi.
I forgot to mention, i cant plot IM3 components.

Title: Re: cadence problem : IP3 with PWL
Post by tm123 on Nov 18^th, 2013, 7:51am

What kind of circuit are you trying to simulate? Although some designers use PSS+PAC to run 2 tone simulations in less time, I think this type of analysis injects the second tone as a small signal so your IP3 result may not be accurate. What is preventing you from running a 2 tone transient, 2 tone PSS, or 2 tone HB?

Title: Re: cadence problem : IP3 with PWL
Post by purplewolf on Nov 21^st, 2013, 7:50am

There is no option in the port to declare the second signal when i am using input in the form of a text file (pwl file).i oculd no figure out how to simulate??

Title: Re: cadence problem : IP3 with PWL
Post by aaron_do on Nov 21^st, 2013, 5:51pm

Hi,

since you insist on using your own input file, I assume its some kind of special signal. You could run a transient analysis and to a DFT. Then you can backwards calculate the IP3.

regards,
Aaron

Title: Re: cadence problem : IP3 with PWL
Post by Ken Kundert on Nov 22^nd, 2013, 9:53am

PSS should work fine with a PWL source. You are using the PWL source to provide the fundamental and using pacmag to provide the test source, right?

-Ken

Title: Re: cadence problem : IP3 with PWL
Post by rfidea on Nov 23^rd, 2013, 6:31am

Can you please describe why you are using a pwl file as input. IP3 is measured with two sinus signals as inputs. To me it looks like the easiest way is to use a vsin, isin or a port as input, depending on the input interface.