In this paper, we propose an analytical study in the spectral domain of inhomogeneous layers that are characterized in terms of transmission matrices leading to an equivalent circuit representation of the whole multilayered structure. Within the framework of this two-port formalism, we present a new contribution to the computation of the Green's function arising in the analysis of multilayered integrated antennas loaded with inhomogeneous materials. Such materials offer new degrees of freedom and, besides, may allow of pattern control, frequency shifting, and enlargement of the bandwidth. We propose, also, an analytical study of the shielding effectiveness of isotropic inhomogeneous materials located in multilayered configuration. The expression of the shielded fields sustained both by plane wave and arbitrary sources is deduced in a closed analytical form. Numerical results are also presented showing the effects of the electromagnetic parameters on radiation pattern, matching properties and radar cross section of the integrated structure.
Vegni, L., Toscano, A., Bilotti, F. (2003). Shielding and Radiation Characteristics of Planar Layered Inhomogeneous Composites. IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, 51(10 II), 2869-2877 [10.1109/TAP.2002.802099].