BROADSIDE COUPLED STRIP INSET DIELECTRIC GUIDE AND ITS DIRECTIONAL COUPLER APPLICATION

A theoretical and numerical method is presented for the analysis of br oadside-coupled strip inset dielectric guide, The method of analysis i s based on an integral equation formulation and Galerkin's procedure, Besides propagation constants for two fundamental and higher order mod es, the characteristic impedances for the two fundamental modes are ca lculated using the total propagating power and the longitudinal strip currents. The propagation characteristics of the two fundamental modes are then used to compute 4-port circuit parameters that are essential for accurate analysis and design of coupled line circuits, The effect s of various structural parameters on the S-parameters are investigate d and it is found that this broadside coupled strip IDG structure is u seful for the realization of the directional couplers, Examples of str ong and weak directional couplers are given, Furthermore, the propagat ion constants and S-parameters of coaxially excited coupled strips are measured, and are in good agreement with the theoretical analysis.