Broadband polarization rotation reflective surfaces and their applications to RCS reduction

A novel broadband polarization rotation (PR) reflective surface (PRRS) with a high polarization conversion ratio (PCR) is proposed, which can reflect the linearly polarized incident wave with 90° PR. The proposed PRRS consists of a periodic array of square patches printed on a substrate, which is backed by a metallic ground. By connecting the square patch with the ground using two nonsymmetric vias, a 49% PR bandwidth is achieved with a high PCR of 96%, which is a significant improvement from the state-of-the-art 29% PR bandwidth. Moreover, the frequency responses within the operation frequency band are consistent under oblique incident waves. Furthermore, another ultra-wideband PRRS with a periodic array of quasi-L-shaped patches is proposed, which increases the PR bandwidth further to 103%. In addition, the designed PRRS is applied to wideband radar cross section (RCS) reduction. Different arrangements of the unit cells of the PRRS are proposed and their effects on RCS reduction are investigated. To validate the simulation results, prototypes of the PRRSs are fabricated and measured. The measured results are in good agreement with the simulated ones.