Polarization-Insensitive Ultra-wideband Metamaterial Absorber for C- and X-bands

Abstract

This paper presents the design and analysis of a metamaterial-based wideband microwave absorber in the C- and X-band, comprised of lumped resistors, having thicknesses of the order of 0.05 λ mm. The structure was micro-machined on the FR-4 sheet in a periodically arranged array of 15 × 15 unit cells. These unit cells have a dimension of 12 × 12 mm each. The proposed absorber design presents excellent broadband absorption characteristics with relative bandwidth (RBW) of 85.05% covering a bandwidth of 8.02 GHz ranging from 5.42 to 13.44 GHz. The absorption mechanism has been explained with the help of characteristic impedance and surface current densities in the operating region. The designed absorber shows polarization angle independency and wide incidence angle stability for the incident microwaves. The results of the prototype are compared with the simulated results illustrating excellent compatibility with the simulation results. Absorber structure may find its potential use in camouflage applications during war times.