TEM PARAMETERS OF ANGULAR OFFSET STRIP LINES

Strip lines, microstrips and similar transmission lines have been widely considered in the technical literature with reference to structure geometries in which the strip plane is parallel to one or more ground planes or to sides of an outer conductor. In this paper, strip lines of various angular positions are considered and the TEM parameters are derived from numerical inversion of the Schwarz-Christoffel conformal transformation. Both open-sided and completely shielded structures are considered. Graphs and numerical values are presented for characteristics impedances in homogeneous dielectric, with various angles between strip and ground planes or outer conductor walls. In addition, examples are discussed for quasi-TEM impedance calculations in inhomogeneous dielectric, in which a successive overrelaxation procedure is applied to the geometry obtained from the original structure by the inverse Schwarz-Christoffel transformation.