Composite wave-absorbing structure combining thin plasma and metasurface

In order to solve the thickness dependence of plasma absorption of electromagnetic waves and further reduce the backward radar scattering cross section (RCS) of the target, we designed a novel composite structure of a metasurface and plasma. A metasurface with three absorption peaks is designed by means of an equivalent circuit based on an electromagnetic resonance type metamaterial absorber. The reflection and absorption of the composite structure are numerically and experimentally verified. The finite integration method was used to simulate a composite structure of finite size to obtain the RCS. The experimental measurements of electromagnetic wave reflection were conducted by a vector network analyzer (Keysight N5234A) and horn antennas, etc. The research showed that the absorption capacity of this composite structure was substantially improved compared to either the plasma or the metasurface, and it is more convenient for application due to its low plasma thickness requirement and easy fabrication.