High-Power Array Antenna Based on Phase-Adjustable Array Element for Wireless Power Transmission

Abstract

Based on a polarization twist reflector, a novel single-fed high-power and phase-adjustable array element is presented. Without a complicated feeding network, the element is simply excited by a balanced-fed dipole. By rotating the polarization of the driven dipole, the element can provide a continuous and linear phase in the far-field region. With the phase-adjustable property, the element can be a substitute for a digital phase shifter. In addition, field distributions of the element are analyzed through simulation, which prove its advantage of high power-handling capacity. The proposed element is also used to form an 8 × 8 array antenna. Compared to the array with conventional phase shifters, this array not only can achieve a high-accuracy beam control within a small scanning angle, but also can handle high power. The array element and array prototypes are designed, simulated, and measured. The results reveal that the element has an aperture efficiency of 97.7% and a linear phase change from 0° to 53.5° at 5.8 GHz. Additionally, the 8 × 8 array with an unequal power divider can obtain a sidelobe level of -20.2 dB, and its measured maximum gain and aperture efficiency are 27.7 dBi and 85.6%, respectively.