Ultra-wideband Active Absorber Based on Multiple Frequency Selective Surface and Magnetic Layers

In this paper, an ultra-thin UWB absorber is designed by using Non-Foster circuit and Frequency Selective Surface. The absorbing structure consists of Non-Foster matching layer, magnetic material layer with FSS and ground layer. To broaden the absorbing bandwidth, two layers of magnetic materials are shaped by holes. It is verified by simulation that the absorptivity is higher than 80% in 0.15GHz–18GHz when the TM polarized wave is incident. And the thickness of the absorber is about 8mm, which is 1/250 of the operating wavelength. The ultra-thin UWB absorber can be widely used in wireless communication and radar applications.