A W-Band High-Gain Bilayer Transmit-Array Antenna Employing Huygens’ Resonance

A special type of transmissive phase plate, named Huygens’ metasurfaces (HMS), is capable of efficiently manipulating transmitted electromagnetic wavefronts with extremely low back-scattering. Here, in contrast to conventional planar multilayer lens arrays, a transmit-array (TA) antenna based on Huygens’ resonance is proposed for high-gain applications at W -band. The proposed meta-cell is comprised of a pair of parallel metallic strips on opposite sides of a single dielectric substrate connected by a pair of vias, and can independently control the electric and magnetic dipole responses and induce the desired Huygens’ resonance. An equivalent circuit model is used to describe its operation principle in detail. A full 360° phase coverage and a high transmission amplitude can be obtained simultaneously using the proposed unit cell. To experimentally verify the proposed concept and design, a TA antenna is fabricated and tested. The Huygens’ TA prototype exhibits good radiation performance. The measured peak gain of the TA prototype is 34.341 dBi at 87 GHz with an aperture efficiency of 45.7%, and the measured 3 dB gain bandwidth is from 79 to 90 GHz.