Broadband and Thin Circularly‐Polarized Achromatic Transmission Metasurface in Millimeter‐Wave Band

Achromatic metasurface has broad application prospects in fields such as communication, imaging, and radar. However, the current achromatic transmission metasurface requires adjusting the number of layers or the thickness of meta‐atoms to achieve the achromatic property, thus resulting in a greater and uneven thickness of the metasurface. To address this problem, a broadband and thin circularly‐polarized achromatic receiver‐transmitter‐integrated (RTI) metasurface is proposed by introducing a snake‐shaped connecting stripline between the receiver and transceiver patches of meta‐atoms, allowing precise control to the meta‐atom's dispersion by changing the length of the snake‐shaped stripline without the need to increase the thickness or the number of layers of meta‐atoms. The performance of the metasurface is experimentally validated through a planar achromatic meta‐lens and an achromatic beam deflector, achieving good achromatic focusing and refraction in a broadband from 27 to 37 GHz, with the thickness of only 0.28λ 0 at the central frequency. Finally, as an application in a realistic scenario, a stable broadband wireless communication with fixed‐angle transmission and reception is experimentally implemented in the millimeter‐wave bands based on the achromatic deflector.