Wideband Radar Cross Section Reduction of a Coding Metasurface Combined With an Inhomogeneous Plasma

A plasma-coding metasurface composite structure is proposed for broadband radar cross section reduction (RCSR). The composite structure consists of a plasma, a coding metasurface, and an air gap between them. By designing the working frequency of the plasma and coding metasurface, electromagnetic (EM) waves can penetrate the plasma and interact with the metasurface, and EM waves are scattered in multiple directions by the coding metasurface. These scattered EM waves are repeatedly reflected and attenuated by the plasma, forming a broadband RCSR. In our work, an inhomogeneous plasma with a large characteristic frequency span and a uniform plasma combined with a coding metasurface are investigated. The coding metasurface structure covered by inhomogeneous plasma has a wider RCSR frequency band and higher radar cross section (RCS) attenuation than those covered by uniform plasma. An inhomogeneous plasma-coding metasurface structure can achieve a −10-dB RCSR in 116.3% bandwidth.