Transfer matrix about nonlinear network

[sonofsky]

If one circuit network contains some nonlinear devices, such as varactor diodes, can we still make use of the transfer matrix(ABCD matrix)?

 

[volker_muehlhaus]

The usual network matrices, including the ABCD matrix, are for linear operation. If you have nonlinear devices, each set of parameters is valid for small signal operation with a given bias point.

Recently, Agilent had introduced the non-linear X Parameters. These are an extension of S-parameters and add nonlinear terms.

https://en.wikipedia.org/wiki/X-parameters

 

[pancho_hideboo]

If one circuit network contains some nonlinear devices, such as varactor diodes,
can we still make use of the transfer matrix(ABCD matrix)?

If your interest is a behavior of small signal around oeration point determined periodical large signal drive, you can use small signal matrix including frequency conversion effect.

If you use Cadence Spectre, use PSS/PSP or QPSS/QPSP.
If you use Agilent GoldenGate, use SSNA.

Here these analyses give you S-parameters including frequency conversion effects.
If you want to get chain-matrix(ABCD), convert this S-parameter to chain-matrix.

If you use Agilent ADSsim, invoke HB analysis with small signal.
Here you have to run two simulations to get {A,B,C,D}.

Also see the followings.
https://www.designers-guide.org/Forum/YaBB.pl?num=1239997125/1#1