A novel high power frequency beam-steering antenna array for long-range wireless power transfer

Abstract

A novel passive frequency beam-steering linear antenna array is proposed in this paper to be utilized at the transmit side of a long-range wireless power transfer (WPT) system. To assure high power handling for a long-range transfer, the proposed antenna is designed based on stripline technology. Moreover, unlike other reported designs, the antenna array in this paper uses parallel feed while frequency beam-steering. This permits to apply a special synthesis at the radiating elements to minimize the energy wasted at the side lobes. The antenna array uses common-fed dipoles as radiating elements to eliminate the surface current at the ground planes that is considered a critical issue in high power applications. The antenna covers the frequency band from 1.1 to 1.5 GHz with a reflection coefficient better than −10 dB (VSWR < 2). Consequently, steers its main lobe from 60° to 90° respectively. Being passive, the efficiency of the WPT system is improved as no active component is needed to steer the antenna beam. The antenna is capable of radiating simultaneous, sequential or selective (shuffled) multiple beams for multiple receivers with a half-power beamwidth of 6°, a peak-to-side lobe level better than 20 dB and an average realized gain of 13 dBi. The antenna array handles a peak power reaches 1.6 MW which makes it an excellent candidate for a long-range WPT system.

Keywords

• Antenna array
• Frequency beam-steering
• High power
• Rectenna
• Side-lobe level
• Stripline