Influence of surface wave upon efficiency and mutual coupling between rectangular microstrip antennas

Analytical formulas that describe the influence of the surface wave on the efficiency and coupling between rectangular microstrip antennas are presented. The rigorous formulation is derived from the polarization and electric current distributions when the propagation of the dominant lowest-order TM mode in the dielectric sheet is taken into account. The results are in conformity with those recently deduced by D.R. Jackson and N.G. Alexopoulos (1989) from asymptotic approximations of a rigorous Sommerfeld solution. It is also shown that the surface wave contributes significantly to the mutual coupling, especially in the E plane. The electric and polarization current distributions along the rectangular patch were used along with the propagation of the dominant lowest-order TM/sub 0/ mode in a dielectric sheet to determine the electric field tangential component on the dielectric surface and the antenna efficiency.<>