Mutual coupling between two circular patch antennas integrated in an inhomogeneous grounded slab

The analysis of mutual coupling between two circular patch antennas integrated in an inhomogeneous substrate ¨ia a com- bined spectral domain (SD) and method of moments (MoM) is proposed in this paper. The spectral electromagnetic field inside the inhomogeneous grounded slab is expressed ¨ia the confluent hypergeometric functions, and the spectral electric dyadic Green’s function is deri¨ed. An MoM procedure in the Hankel domain is then applied in order to sol¨e the integral equation on the patch, and to find the unknown current density distribution on the patch itself. Then, the stationary phase method is employed to obtain the radiation pattern, and the mutual coupling between the two patches is also computed. Finally, some numerical results showing the beha¨ior of this kind of antenna are presented