Dual-Band Huygens’ Metasurface Lens Antenna for Automotive Millimeter-Wave Radar

This paper proposes a dual-band orthogonally linear-polarized Huygens metasurface lens antenna operating at 60/77 GHz for automotive radar systems. A novel orthogonal unit cell configuration is introduced to minimize inter-polarization coupling while achieving near-360° phase coverage. The design leverages a low-profile architecture with only two metallic layers, implementing Huygens metasurface principles to enable dual-frequency operation. Orthogonal element arrangement effectively suppresses mutual coupling between bands. Simulations demonstrate transmission magnitudes exceeding 0.73 at 60 GHz and 0.75 at 77 GHz, with phase coverage of 350° and 340°, respectively. Prototype measurements reveal a peak gain of 25.33 dBi with 7.7% 3-dB gain bandwidth at 60 GHz, and 25.56 dBi gain with >10.4% 3-dB gain bandwidth at 77 GHz. Compared to conventional lens antennas, the proposed metasurface lens exhibits superior profile reduction and dual band functionality, enhancing overall system performance.