Analysis of unbounded and bounded circuits considering finite substrate extent and inhomogeneous dielectric layer.

A generalized method of lines algorithm is presented for characterizing unbounded and bounded circuits. Finite substrate extent and inhomogeneous dielectric layers are rigorously considered in this field-based model. Radiating properties of unbounded regular and irregular microstrip patch resonators and arrays are studied with emphasis on effects of mutual coupling and finite dielectric extent on complex resonant frequencies. In addition, unbounded loss effects for microstrip open-end and 90° angular bend deposited on finite substrate as well as chip-to-chip discontinuities are also investigated. Our developed algorithm incorporates an absorbing boundary condition using the Padé approximation to simulate any potential radiation and leakage losses for resonator structures while an improved lossy absorbing boundary condition (LABC) that can handle both propagating and evanescent waves is used to determine the unbounded effects for waveguiding structures. Results indicate interesting properties of the finite extent of dielectric substrate on resonance and radiation characteristics, and also on unbounded radiation and leakage losses. Copyright © 2000 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]