Polarization and Angle Insensitive Ultrathin Wideband Metamaterial Absorber Based on Indium-Tin-Oxide

In this work, we designed an ultrathin wideband metamaterial absorber giving wide incident angle stability and polarization insensitivity. The unit cell consists of a two-layer structure based on polyethylene terephthalate and indium tin oxide with a size of 1.5 mm × 1.5 mm ×2.0 mm. The absorber gives more than 90% absorption at a normal incident angle from 14.72 GHz to 65.41 GHz with an absorption bandwidth of 50.69 GHz. The absorber is also simulated under an oblique incidence angle to check its wide incident angle stability. The simulation results show that under the transverse magnetic mode, it gives more than 90% absorption up to 60°; under the transverse electric mode, it gives almost 90% absorption up to 45° incident angle. The absorber is also polarization-insensitive.