Equivalent permittivity analysis for periodic wedge‐type absorber using transmission mode approximation

Abstract

AbstractTo obtain a matching over a wide frequency range, pyramid‐type and wedge‐type matching layers are used in front of the multilayered wave absorbers. In this paper, a transmission mode approximation is proposed in which the period of the wedges and the incident polarization direction are taken into account in the calculation of the characteristics of a wedge‐type wave absorber. the degree of difference of the equivalent permittivity derived by the propagation mode approximation from the one by the conventional method (corresponding to the low‐frequency limit) is presented by numerical calculations. It is also shown that there is a difference from the wave absorber characteristics derived by the conventional method even at a wavelength longer than the wedge period. the tendency of the reflection to increase at the higher frequency side is visually explained by replacing it with the taper shape.