Novel distributed circuit model for transition between coplanar waveguide and microstrip by using the generalized telegrapher equation method

Abstract

AbstractIn this article, a novel distributed circuit model of coplanar waveguide to microstrip (CPW‐M) transition is presented by using generalized telegrapher equation. In comparison with conventional nonuniform transmission line equation, the generalized telegrapher equation has two additional terms, dependent series voltage and shunt current sources, which represent local radiation effect from discontinuities of the nonuniform transmission line itself. Based on the full‐wave numerical results, the distributed circuit parameters can be extracted by using the generalized telegrapher equation. Since the generalized telegrapher equation coefficients are determined by dynamic numerical methods and the coefficients are invariant with the line excitation and load, the equation is dynamical rather TEM. The numerical experiments show that the novel distributed circuit model for this CPW‐M transition can have broadband characteristics. As a preparatory experiment, an improved CAD method using this model is utilized to model different structures of CPW‐M transition. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1323–1328, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22461