SiO2-Based High-Gain Millimeter-Wave Transmitarray Antenna

A flat millimeter-wave transmitarray with a three-layer element is investigated in this paper. The proposed element can provide 360° phase coverage with a transmission coefficient better than -3 dB at 160 GHz. Then a transmitarray based on the element is designed with a focal-to-diameter ratio of 0.69, illuminated by a pyramidal horn antenna connected with WR-05 waveguide. The transmitarray is fabricated using the microfabrication technology based on SiO2 substrates, and the measured results demonstrate the performances of the antenna, a peak gain of 24.9 dBi with an aperture efficiency of 23.2%. In general, the proposed transmitarray verifies the feasibility of the microfabrication technology and can provide an alternative solution for applications in millimeter-wave systems.