A High Efficiency Bandwidth-Improved Transmitarray Antenna with Phase-Shifting Elements

This paper presents a high efficiency and bandwidth-improved transmitarray antenna. The antenna employs a phase-shifting element with three metallic layers. This element is based on the principle of polarization conversion, which enables a phase coverage of approximately 300° by adjusting the relevant parameters in the phase-shift element. This element features a low transmission loss throughout the entire working frequency band. An improved phase compensation scheme is proposed to enhance the efficiency of the array antenna. This scheme incorporates the introduction of a reference phase and a more precise evaluation function to calculate the weighted phase errors corresponding to different schemes. A transmitarray comprising 20 × 20-element is designed with the phase-shifting elements. The simulated results show that the 1-dB and 3-dB bandwidth are 16.8% and 28.8% respectively. Within the 1-dB gain bandwidth, the aperture efficiency is better than 31%, and the peak aperture efficiency and peak gain are 47% and 28.4 dBi.