Multiband Metasurface‐Based Absorber for Applications in X, Ku, and K Bands

Abstract

AbstractIn this paper, a slotted‐circle patch metasurface that can efficiently absorb electromagnetic (EM) waves in three different bands is proposed. Based on the fundamental resonance of a single circular patch, EM resonances are generated making slits in the circular patch leading to multi‐band operation. Simulation results show that the proposed structure can absorb signals in three different bands, namely at 8.10, 15.39, and 19.7 GHz with absorption peaks of 99.8%, 99.7%, and 99.8%, and absorption bandwidths of 132, 181, and 90 MHz, respectively. The absorption mechanism is discussed on the basis of the single‐layer effective medium model and the analysis of surface current and electric field distributions. Furthermore, the experimental results show good agreement with the numerical simulations, with an average absorption greater than 99%. The 2‐mm thick absorber is electrically thin, corresponding to ∼λ/18 at its lowest operating frequency. Compared to other published designs, the proposed absorber has a single resonator with simple geometry, but operates in multiband. Therefore, it can be used in many applications such as anechoic chambers, scattering control, photodetectors, microbolometers, and solar cells. The proposed metasurface absorber can be used for microwave energy harvesting as well as sensor and radar cross‐section reduction applications.