Radiation and scattering features of patch antennas with bianisotropic substrates

The analysis of patch antennas residing in cavities filled by general inhomogeneous and lossy bianisotropic substrates is presented in this paper. The theoretical study is based on a variational formulation associated with the boundary value problem under analysis, and a hybrid finite element-boundary integral method is employed to numerically solve the electromagnetic field inside and outside cavities. Initially, the general formulation presented here is applied to some particular cases known in the literature. Then, the main scattering and radiation features of cavity backed patch antennas with chiral, anisotropic, and bianisotropic materials are presented. Particularly, it is shown that complex media allow for frequency control and for a reduced antenna size at a given operating frequency.