Using Efficient Model-Based Parameter Estimation for Pole-Free Solutions of Modal Propagation Constants, as Applied to Shielded Planar Structures

Abstract

A fast and efficient adaptive sampling algorithm is applied to model-based parameter estimation of a Method-of-Lines implementation of two- and three-layer shielded planar structures, creating a pole-free function for the calculation of the propagation constants. The technique minimizes the number of characteristic equation evaluations, and hence reduces the computation time by orders of magnitude when compared to methods using the characteristic equation directly. Examples of a shielded microstrip line and a finline structure are shown below. Between 3 and 15 evaluations of the characterisic function are typically required per determination of an imaginary or real zero.