Coupling modeling and reduction techniques of cavity-backed slot antennas:FDTD versus measurements

Cavity-backed slot (CBS) antennas are commonly used in earth-based and spac e-borne applications. In this manuscript, the finite-difference time-domain (FDTD) method is used to analyze different antenna characteristics of such elements including input impedance, coupling, and radiation patterns. Emph asis is given on coupling calculations especially on different methods to r educe coupling. Specifically, coupling reduction is attempted using lossy m aterial superstrates or ground plane discontinuities, such as slits. Numeri cal issues concerning the analysis of CBS antennas in the context of FDTD a re also discussed.