Frequency-Selective Absorber with Ultra-Wide Absorption Band And Adjustable Notch Band

This paper proposes a frequency-selective absorber (FSA) with ultra-wide absorption band and adjustable notch band. The top layer of the structure is a lossy layer, which uses a traditional ring structure with lumped resistors inserted in the four sides and round metal patches on the four corners. A notch resonator is placed on the top of bottom substrate as the lossless layer instead of the metal plane used in traditional absorber. The structure of this paper realizes the adjustment of the notch band by modifying the value of the capacitors in the lossless layer without reducing the absorption performance. The proposed FSA has a simple structure and an ultra-wide absorption band of 5-22 GHz, which has good stealth performance and application prospects.