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How to extract s2p file from a large-signal model in ADS?

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Full Member level 3
Mar 1, 2022
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I have a s2p file of a RF IC which it contains frequency from 650 MHz to 1.1 GHz. I wish to modify s2p model so that two frequency 0 Hz and about 3.5 MHz is added to the s2p file.

How can I do that with this s2p file?

I have uploaded the link to the s2p file. I hope it help.

click on it:
s2p file link

Another point to mention is that I have the large-signal model too. But, it takes a lot of time to do transient simulation. So I hope doing transient simulation using s2p file decreases the number of connections in my schematic environment and therefore, simulation is done much more faster.

s-parameters are not defined @ 0.0000 Hz. They are defined in very low frequencies even in Hz range but not DC.
Adding s-parameters @2 frequencies into s2p file will not solve your problem. The simulator will do an extrapolation between 650 MHz and toward to DC and it will bring serious errors.
In order to obtain s-parameters of a device, bias the device properly and do s-parameters analysis between the frequencies which you're interested in and where the large signal model is still valid.
Transient simulations don't give you any small signal parameters of a device or a circuit. Learn something about it.
Also, due to discrete nature of s-parameters, transient simulations do not like them.

s-parameters are not defined @ 0.0000 Hz.

I use S-parameters at 0 Hz all the time to model wideband structures.

Imaginary part is 0, and real part is well defined, e.g. from series or shunt resistances. You could also convert Z or Y parameters at DC to S-parameters if that feels more intuitive.

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