The absorber realized by 2D photonic crystals with plasma constituents

Herein, a tunable metamaterial absorber was realized by using two-dimensional (2D) plasma photonic crystals (PPCs). A photonic band gap (PBG) can be obtained in the proposed 2D PPCs, which runs at frequencies from 1.7 to 1.93 GHz. The fabricated absorber is tunable and is composed of excited plasma tubes with 2D square lattices. The resonances originate from the all-dielectric resonances. The plasma frequency is also measured. The experimental results agree with the simulation results. The fabricated absorber shows excellent absorption (up to 84.3%). Hence, it can be used to design various devices, such as tunable microwave devices, stealth devices, and reconfigurable antennas.