Higher order modes and crystallographic axis angular dependence of propagation in anisotropic pbn using a spectral matrix method

Abstract

A 4×4 field matrix method for layered structures is employed to numerically calculate the propagation constant γ for coupled microstrip on a highly anisotropic material, Pyrolitic boron nitride (PBN). This new technique is very versatile, and allows the determination of γ for arbitrary permittivity, principle axis crystallographic orientation θ. Even and odd mode propagation constants are found for θ = 0°, 45°, and 90°. The approach is fully dynamic, yielding the dispersion characteristics of each of the modes studied. Numerical data is provided in the microwave and millimeter wave regions.