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 --->∞). 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.