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Simulators >> RF Simulators >> Shooting Method Question
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Message started by rickk on Mar 20^th, 2003, 5:57pm

Title: Shooting Method Question
Post by rickk on Mar 20^th, 2003, 5:57pm

I'm trying to build a simulator that can perform a periodic-steady-state analysis using the "plain" shooting method (w/out krylov). I already have a simulator that can perform a transient analysis with reactive and non-linear elements using the backward euler method.

I'm having trouble calculating the Jacobian. In Kundert et al's papers, there is reference to the C/h+G matrices. However this is assuming the plain nodal analysis approach. My question is this, How do I calculate the Jacobian with modified nodal analysis (MNA) stamps?

Title: Re: Shooting Method Question
Post by skippy on Mar 23^rd, 2003, 5:54pm

The G matrix is the conductance, or di/dv terms.

The C matrix is the capacitance, or dq/dv terms.

h is the time step.

For MNA you would need to swap the rows of your voltage sources with other rows so that you do not have a 0 diagonal element in your Jacobian.

The C/h elements for inductors would probably be something like L/h.

Rodgrigues has a pretty good book
Computer-Aided Analysis of Nonlinear Microwave Circuits
Author: Paulo J. Rodrigues, Artech house, 1997

but its focus is mainly in the frequency domain.

There is also a much older book by McCalla which talks about MNA stamps:
W. J. McCalla, Fundamentals of Computer-Aided Simulation. Boston: Kluwer, 1987.

Title: Re: Shooting Method Question
Post by skippy on Mar 23^rd, 2003, 5:58pm

I have heard that certain aspects of the Shooting Method with respect to the use of iterative methods are patented? Could someone (perhaps K Kundert) tell me which parts are?

Title: Re: Shooting Method Question
Post by Ken Kundert on Mar 25^th, 2003, 11:50am

To simplify notation when writing papers I always formulated the methods in terms of nodal analysis with the understanding that the formulation could be extended to MNA by assuming that C is the portion of the Jacobian that is associated with the time-derivitive terms and G is everything else.

There are patents that address the application of Krylov techiques to shooting methods, but none that I am aware of that cover the base shooting methods.