Generalized Phase-Polarization Cancellation for Broadband Radar Cross-Section Reduction

This study presents a novel approach to decrease the radar cross-section (RCS) by integrating and expanding the phase cancellation and polarization conversion methods. In this proposed technique, only one unit cell, akin to the polarization conversion method, is utilized. The RCS reduction surface is comprised of arrays of this unit cell; each array is rotated by 90 degrees in relation to its neighboring arrays. Unlike previous RCS reduction methods, which employed periodic arrangements of unit cells that either kept the polarization of the reflected wave unrotated or rotated it by 90 degrees, the proposed generalized method enables the unit cells to rotate the polarization of the reflected wave arbitrarily. This is achieved by eliminating the symmetry requirement in the unit cell design. The mathematical theory for the proposed RCS reduction method has been developed. To demonstrate the method’s feasibility, a unit cell was designed using a pattern optimization method based on the pixelization of the cell surface, and a binary particle swarm optimization algorithm was employed as a proof of concept. A surface was formed by constructing
$4\times 4$
arrays of
$7\times 7$
designed unit cells, where each array was rotated 90 degrees relative to its side array. The measured results demonstrate a 10-dB monostatic RCS reduction bandwidth of 115%, from 2.8 GHz to 10.4 GHz, which is in excellent agreement with the bandwidth obtained using the developed theory.