From Kirchoff to Lorentz modifying-circuit theory for microwave and mm-wave structures

Microwave and mm-wave designs require circuit parameters, which are applicable at high frequencies, where the conventional transmission line theory has failed to provide correct results. The traditional remedy is to add spurious capacitors and inductors at vulnerable locations, such as line discontinuities and terminations. These parameters are hitherto extracted from electrostatic field solutions. When the frequency becomes so high that the statically extracted parameters lose their effectiveness; the field theorists have decided to solve the problem with full wave formulations. They may have succeeded in solving the field problems, but are not able to convert the field results into parameters that are useful to circuit designers. This paper presents a procedure of parameter extraction from dynamic field solutions. The parameters are inductors, capacitors and dependent sources, which are all traditional components in circuit theory. When those circuit parameters are connected and solved, they reconstruct the currents and voltages of the dynamic field solutions.