Reduction of the RCS of Metal Cylinder Using Conformal Anisotropic Metasurface and Linear Tightly Coupled Dipole Array

Abstract

In the paper, the use of a cylindrical anisotropic metasurface (MS) and a passive tightly coupled dipole array (TCDA) to reduce the radar cross section (RCS) of a metal cylinder is considered. The metasurface and TCDA are conformally located on a circular perfectly conducting cylinder on top of a thin substrate. The cells of the MS contain conductive elements in the form of a “figure-eight” with angles of slope of the anisotropy axes ±45° (relative to the z axis). Using HFSS, the effect of 1-bit azimuth coding of MS and passive modes of TCDA operation on the RCS reduction on co-and cross-polarizations in the band from 8 to 18 GHz was investigated. It is shown that dipole loads (short circuit, open circuit, 50 hm) or perfectly matched dipole ports affect the frequency characteristics and RCS patterns on co-polarization, but slightly change the RCS on cross-polarization when the cylinder is irradiated with a plane E-wave. In the case of an incident H-wave, the effect of TCDA loads on RCSs on co- and cross-polarizations is small. The effectiveness of monostatic RCS reduction, the angles of deep cancellation of bistatic RCSs on cross-polarization, and the effect of TCDA on RCS depend on the azimuth angle of incidence of a plane wave. In the case of an incident H-wave, the effect of TCDA loads on RCSs on co- and cross-polarizations is small. The effectiveness of monostatic RCS reduction, the angles of deep cancellation of bistatic RCSs on cross-polarization, and the effect of TCDA on RCS depend on the azimuth angle of incidence of a plane wave.