Millimeter-Wave High-Efficiency Double-Layer Transmitarray Antenna Using Miniaturized Dual-Polarized Elements

A high-efficiency wideband double-layer transmitarray antenna (TA) using miniaturized array elements is proposed in the study for millimeter-wave (mm-Wave) applications. The transmitarray consists of 484 dual-polarized elements. Each element is composed of only two layers of identical modified Jerusalem crosses printed on a dielectric substrate. Additional stubs are used for size reduction, leading to a compact size with a periodicity of only
$0.44 \lambda _{0}$
. It contributes to a high aperture efficiency for the proposed TA. TA is designed, fabricated, and measured. It achieves a peak gain of 28.67 dBi at 31 GHz and a high aperture efficiency of 44%–61.3% within the 1 dB gain bandwidth, which is 10.3% (29.5–32.7 GHz) in the measurement. The proposed dual-polarized double-layer TA demonstrates simplified design complexity, reduced thickness and mass, and lower cost compared with the conventional TAs. It also exhibits high radiation gain and high aperture efficiency.