Analysis of microstrip open-end and gap discontinuities in a substrate-superstrate configuration

Abstract

A study of microstrip open-end and gap discontinuities in a two-layer structure is presented. The analysis is based on the method-of-moments solution of a full-wave integral equation. A combination of semi-infinite modes and subdomain modes is used. The transverse dependence of the expansion functions is obtained through a two-dimensional infinite analysis. A parametric study of the material effects on the radiation and surface-wave losses, and the fringing fields at the discontinuities is also performed. The analysis shows good agreement in the limiting case with the quasistatic method.<>