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

Abstract

This paper presents design and analysis of Metasurface-based wideband Microwave Absorber Comprised of Lumped Resistors having a thickness of the order of 0.05 λ mm operating in the C-, X- and Ku-bands. Structure has been micro machined on a FR-4 sheet in a periodically arranged array of 15x15 unit cells. These unit cells have a dimension of 12x12 mm each. The proposed absorber design presents excellent broadband absorption characteristics with relative bandwidth (RBW) of 93.3% covering a bandwidth of 8.02 GHz ranging from 5.42 GHz 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. Results of the prototype when compared with the simulated results illustrate a wider compatibility with the simulation results. Absorber structure may find its potential use in camouflage applications during war times.