Triple Band Polarization Independent Ultrathin Metamaterial Microwave Absorber for C and X Band Applications

Abstract

The proposed model in this paper introduces a triple band polarization independent microwave absorber for C and X band applications. The proposed unit cell design proffers a cyclo-square shaped resonator at the centre surrounded by quarter part of circular ring resonator with different thickness at each corner on metal ground platted dielectric substrate. The proposed design is polarization insensitive, conformal and stable under oblique incident angle for TE and TM polarized wave up to 45°. Ultrathin thickness of $0.0064\lambda_{0}$ at the lowest frequency of absorption is reported. The absorption peaks of 95.0%, 96.25% and 95.53% are obtained at 6.01 GHz, 9.55 GHz and 11.65 GHz frequencies of resonance. It demonstrates FWHM bandwidths of 158.5 MHz (5.94 GHz -6.10 GHz) for first band, 261.6 MHz (9.42 GHz - 9.69 GHz) for second band and 296.1 MHz (11.51 GHz -11.81 GHz) for the third band. The surface current distributions for all the three absorption frequencies are analyzed to study the absorption mechanism.