A general method for calculating the characteristics of microstrip transmission lines

A general method is proposed for analyzing the propagation characteristics of microstrip transmission lines within a transverse electromagnetic wave approximation. These transmission lines are characterized by conducting strips, large groundplanes, dielectric layer insulation, and planar geometry. The method is based on the Green's function integral approach for formulating the problem. Numerical results were obtained by solving the integral equation using the subinterval method. Numerical results are presented for single and coupled microstriplines. A synthesis procedure is described which gives the geometry of a pair of coupled microstrip lines that corresponds to prescribed electrical properties. Further application is made to the design of PIN diode phase shifters and for active phased array modules. Computer programs written in FORTRAN IV are included.