An Investigation of the Mutual Coupling and Tuning of a Miniaturized Metamaterial Absorber

This work is related to a metamaterial based microwave absorber design consisting of a single dielectric layer with a rectangular split-ring resonator and a T-type resonator printed on one side and a metal film coating on the other side. The structure is investigated to determine the effect of mutual coupling between the two resonators on the resonance frequencies. Due to the distinct resonance frequencies of the resonators, the absorber can operate in two frequency bands, i.e., 7.82 GHz and 9.65 GHz. Each of the resonance frequencies can be easily controlled by a single parameter without affecting the other. The surface current distributions at both the frequencies are presented and analysed to better understand the absorber behavior. To realize the absorber, a standard WR90 hollow waveguide (X-band) measurement setup is used. Simulation and measurement results show similar trends; differences are discussed.