A wideband biconic shape metasurface for polarization conversion and radar cross-section reduction

Abstract A single-layer polarization converting metasurface (PCMS) with wideband is presented for polarization conversion and radar cross-section (RCS) reduction. The proposed PCMS is composed of metallic biconic shape resonator imprinted on a metal-backed F4BM dielectric substrate of relative permittivity 2.2 and loss tangent 0.001. The unit cell has a compact size of 0.16 $\lambda_\mathrm{o} \times 0.16\lambda_\mathrm{o}$ . A comprehensive parametric analysis, angular sensitivity study, bistatic and monostatic RCS analysis are conducted by illuminating the proposed PCMS using linearly polarized (LP) plane waves. The PCMS converts LP electromagnetic waves to their orthogonal polarization state in the frequency band of 8.7–24.8 GHz resulting in polarization conversion ratio over 90% with a fractional bandwidth of 96%. Additionally, the developed structure is applied in chessboard configuration, using phase cancellation techniques for RCS reduction, that achieve 10 dB RCS reduction across a wideband of 7.9–23.4 GHz. The unit cell and its rotated version has a cross-polarization reflection phase difference of ( ${180}\pm {37}{^\circ}$ ) in the operating band, which fulfill the criteria for RCS reduction. The chessboard configuration exhibits a scattering pattern with four strong lobes that deviates from the normal incident path because of the phase cancellation in normal direction. The experimental results are in good agreement with the simulated result. Applications for the developed structure include antenna design (gain enhancement and beam steering), target hiding, imaging, and microwave communications.