A metasurface composed of 3-bit coding linear polarization conversion elements and its application to RCS reduction of patch antenna

TL;DR

This paper introduces a 3-bit coding metasurface that effectively reduces the radar cross section of a patch antenna across a broad frequency range without significantly affecting its performance.

Contribution

It presents a novel 3-bit coding metasurface design with equivalent circuit models for dual polarization, applied to enhance RCS reduction of patch antennas.

Findings

Significant broadband RCS reduction demonstrated in simulations and experiments.

Metasurface design maintains antenna performance while reducing RCS.

Equivalent circuit models accurately describe unit cell behavior for dual polarizations.

Abstract

In this paper, a low radar cross section (RCS) patch antenna based on the 3-bit metasurface composed of linear polarization conversion elements is designed. At first, 3-bit coding metamaterials are constructed by a sequence of eight coded unit cells, which have a similar cross-polarized reflected amplitude response and gradient reflected phase responses covering 0~2{\pi}, respectively. Equivalent circuit models (ECMs) of these unit cells are created to describe their electrical behavior for the two linear incident polarizations at the same time. Then, a patch antenna is integrated on the 3-bit metasurface, of which the elements are placed with a 2-dimensional linear coding sequence. The metal square ring is set around the patch antenna to protect it from the disturbance of metasurface. Both the simulation and experiment results demonstrate that the designed metasurface can primarily reduce the antenna RCS at a broadband, while the antenna performances are not degraded significantly.