Characterization of radar absorber based on square patch textured surface

Abstract

A square patch can operate whereby at the resonance frequency of resistively textured surface. The surface behaves like a perfect magnetic conductor; therefore the electric field would be in tangential to the surface. The developed patch that consists of square shape of metallic copper with length of 22mm and gap between patches of 2.0mm is placed on a single-sided 3.2mm thick grounded FR4 Epoxy dielectric substrate. Relative permittivity and tan δ of the dielectric substrate are 4.04 and 0.02, respectively, whilst the thickness of metallic copper top patch as well as the ground plane is 0.035mm. The losses of dielectric substrate and copper conductive are also taken into account. Surface-mounted-resistive elements are incorporated midway connecting between the adjacent patches to reduce the amount of backscatter from the surface. The reflection coefficient of absorber with resistive elements of 440Ω where upon the incident electromagnetic energy should be absorbed is up to 34dB.