Evaluation of Mutual Coupling of Twin Radiating Thick Rectangular Window Apertures Backed by a Ground Plane

Abstract

A moment method analysis of twin inductive, capacitive, and resonant window radiators radiating through an infinite conducting plane and one of them fed by rectangular waveguide is presented. The boundary conditions at the four interfaces are derived by taking into account the finite thickness of the windows. The application of moment method transforms the integral equations representing the boundary conditions into a matrix equation, the solution of which by matrix inversion gives the aperture basis functions. The reflection coefficient seen by the feeding waveguide and the coupling coefficient seen by the coupled waveguide are evaluated from these basis coefficients. Good agreement between theoretical and experimental values of reflection coefficient and coupling coefficient is obtained.