Metasurface Design for RCS Reduction Applications

In this paper, a novel wideband radar cross section (RCS) reduction metasurface is proposed based on polarization conversion. The unit element features a double arrowhead structure combined with a square metallic loop, arranged in an array with mirror elements rotated 90° for polarization conversion, enabling RCS reduction in reflective mode. The unit cell and its mirror function as a cross-polarizer from <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$9.7-31.8 \text{GHz}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$34.2-35.2 \text{GHz}$</tex>. The metasurface is implemented in a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$25 \times 25$</tex> array on a cost-effective FR-4 substrate with 0.18 mm thickness and overall dimensions of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$6 \times 6$</tex> inches. Simulated and measured results show an RCS reduction of 10 dB, with peak reductions of 20.83 dB from <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$10.7-12.3 \text{GHz}$</tex> and 30.12 dB from <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$18.5-34.5 \text{GHz}$</tex>, compared to a flat metallic plate of identical size. The measurements align well with simulations.