ABSTRACT
Artificial magnetic conductor (AMC) elements are capable of reducing structural RCS of microstrip patch arrays. The bandwidth and the extent of RCS reduction they can provide depend on the type of AMC element chosen, its resonant frequency and other design parameters, and also the configuration designed. A combination of AMC cells and square patches in chessboard configuration provide narrowband RCS reduction through phase cancellation of reflected waves. However, by implementing a hybrid chessboard configuration of AMC-square patch on the ground plane of an antenna/array, wide band reduction can be achieved. This chapter deals with the EM design and analysis of chessboard configuration of HIS layer along with hybrid HIS-based ground plane in a planar patch array as a three and two layered structure. It is demonstrated that the scattering behavior of a microstrip patch array can be varied, without affecting the radiation characteristics, if the ground plane is replaced with a suitable configuration of AMC elements. The RCS analyses show that the patch array with hybrid HIS-based ground plane provides specular RCS reduction in the out-of-band frequency range with an optimum RCS in the in-band frequency range, when compared to patch arrays with conventional metallic ground plane.
