Design of Wideband Radar Absorbing Structure Based on Lossy Frequency Selective Surface

摘要

This paper proposed a novel design of a metamaterial absorber with wideband absorption, wide incident angle and polarization insensitivity. Based on resistive film structure (lossy frequency selective surface), this metamaterial absorber unit consists of a nut ring shaped resistance film, a polymethacrylimide foam and a metallic ground. Simulated reflectivity and absorption rate show that the absorber has a strong absorption of over 90% for normal incident wave. The absorption band ranges from 4.05GHz to 17.96GHz, basically covering C, X and Ku band. Simultaneously, the absorber has no significant change for TE or TM wave at different polarization angle, showing good polarization insensitivity. The absorber also exhibits broad angle absorption characteristics of over 80% absorption with incident angle from 0-40°. The reason for the wideband absorption characteristic of the absorber is quantitatively explained from the perspective of multi-reflection interference theory. The calculated results agree well with simulated ones.