A High-Efficiency Dual-Polarized Transmitarray Antenna with Flat Gain Performance

This article presents a high-efficiency dual-polarized transmitarray antenna which achieves flat gain characteristics. First, a wideband triple-layer subwavelength element is designed, achieving high transmission amplitude and a full 360° transmission phase range at 10 GHz. To enhance the passband, an isolated element and a cross-shaped middle layer are incorporated. Additionally, four vias connect the top and bottom layers to induce the current resonance, extending the phase range to 360° and improving the radiation efficiency. Based on the element, a transmitarray prototype with 185 elements is fabricated and measured, showing a gain of 27.1 dBi at the center frequency 10.2 GHz, with a radiation efficiency of 58.9%, and a 0.5 dB gain bandwidth of 12.7%. Within the 1 dB gain bandwidth, a minimum radiation efficiency of 37% is achieved at 11.4 GHz.