A theoretical and experimental study of mutual coupling in microstrip antenna arrays

Each microstrip antenna element in the array is replaced by an equivalent magnetic current source distribution over a grounded dielectric slab derived from the electric field on the walls of the element as given by the cavity model. A dyadic Green's function is developed for a grounded dielectric slab, using the rectangular vector wave functions. The function is used to calculate the magnetic field due to the magnetic current distributions. The formula for mutual impedance based on the reaction concept is used to calculate the mutual coupling in arrays of antenna elements. Some measurements have been conducted for mutual coupling between two rectangular patches in the C-band. Calculated results are in excellent agreement with measurements, including those of other authors.< >