A Dual- Polarized Metalens with Wide Field-of- View and Broad Bandwidth for 77GHz Radar Applications

This research introduces a novel approach to designing a dual-polarized metalens that exhibits wide field-of-view (FOV) with a broad bandwidth (71–87 GHz). The metalens is composed of three metallic layers, with an ultra-thin thick-ness of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.13λc</tex> , and a large numerical aperture (NA=0.707). To address the off-axis aberration, we design a wide FOV metalens with two types of unit cells and an optimized polynomial phase profile. To validate our approach, a dual-polarized metalens with a diameter of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">20λc</tex> is designed and simulated. The simulation results demonstrate that the metal ens achieves high focusing efficiencies, tight focal spot sizes (Strel Ratio <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$> 0.75$</tex> ) and low sidelobe levels ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">≤-10dB</tex> ) across a wide angular range of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[-45∘, 45∘]</tex> . The proposed dual-polarized metalens holds promising potential for applications of millimeter-wave radars.