Computation of Propagation Constants for the Fundamental and Higher Order Modes in Microstrip (Short Papers)

A method used to treat static problems in microstrip is extended to treat time-harmonic problems of covered and uncovered microstrip. Both longitudinal and transverse currents are taken into account, Impedance functions (integrals of Green's functions) for covered and uncovered microstrip are derived in terms of improper integrals (limits 0 --->/spl infin/). Accurate evaluation of these integrals is carried out. Matrix methods are then used to obtain propagation constants for the fundamental and higher order modes. Data obtained agree closely with experiment.