Propagation characteristics of single and coupled microstrip antenna feed-lines on anisotropic substrates

Both biaxial permittivity and permeability tensors are considered for the analysis of open single and coupled microstrip lines by using the spectral-domain approach. Based on Maxwell's equations in the spectral domain and the appropriate boundary conditions, the dyadic Green's function is obtained, and the propagation characteristics of these transmission lines are numerically examined. To verify the formulation, both sapphire and boron nitride substrates were used for single and coupled microstrip lines. The computed data indicate very good agreement with independent results from previous research.<>