Coupling factor of H-plane coupled rectangular microstrip antennas

Mutual coupling between rectangular half wavelength microstrip antennas fed by a coaxial line at the center of one of the radiating edges is investigated. A closed-form expression for the mutual coupling is developed for the H-plane configuration by which the coupling factor of these antennas may be accurately computed. The agreement between the theoretical model and measurement by previous researchers is fairly good. This expression can be readily used in the computer-aided design of microstrip antenna arrays.<>