Asymmetric Transmissive Chiral Metasurface Enabled Triple-Band Circular Dichroism

This paper presents a bi-layer, double-F-shaped asymmetric transmissive chiral metasurface (ATCM) designed to achieve a pronounced triple-band circular dichroism (CD) effect and asymmetric transmission (AT) within the microwave frequency range. The proposed ATCM demonstrates selective polarization transmission when subjected to right-hand circularly polarized (RHCP) and left-hand circularly polarized (LHCP) waves incident in the forward and backward directions, resulting in significant CD effect at three distinct frequencies in the K-band: 18.788 GHz, 20.140 GHz, and 21.528 GHz, with maximum CD values of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.75,0.6$</tex>, and 0.4, respectively. The high-performance characteristics of the ATCM, including its strong polarization selective and AT capabilities, make it a promising candidate for a wide range of applications, including analytical chemistry, imaging, sensing, spectroscopy, satellite communications, and the development of advanced components for next-generation communication systems.