Wideband Angular Stable Absorber Based on Spoof Surface Plasmon Polariton for RCS Reduction

A wideband absorber with high angular stability based on spoof surface plasmon polariton (SSPP) is proposed in this letter. The absorber consists of a metal ground and an SSPP structure that comprises nine incurved metallic strips loading lumped resistors. It realizes wideband absorption in the range of 6.95-17.4 GHz (factional bandwidth of 85.8%) for the normal incident wave and maintains high absorptivity when the incident angle tilts to 60 degrees and 65 degrees for transverse electronic (TE) and transverse magnetic (TM) waves, respectively. As a reflector of a Vivaldi antenna, the proposed absorber reduces the bistatic radar cross section (RCS) effectively and does not decrease the performance of the antenna. Prototypes of the absorber and antenna are fabricated and measured. The simulated and measured results have a good agreement, which verifies the wide-angle absorption of the proposed absorber and its good work in bistatic RCS reduction.