Phased Array-Free Multi-Directional 5.8 GHz Wireless Power Transmission Using A Fresnel Lens

Steerable arrays are often developed based on complex phased arrays or lossy beamforming networks, making them unsuitable for pervasive wireless power transmission (WPT) applications. Here we propose the first sub-6 GHz quasi-optical beam-steering WPT dielectric lens-based system. The lens has an area of $16.6\lambda_{0}^{2}$ with a height of $0.83\lambda_{0}$ , achieving an aperture efficiency of 44.7% and a gain improvement of 10 to 14 dB from 5.2 to 6.5 GHz. $\mathrm{A}\pm 60^{\circ}$ beam-scanning angle is achieved with linear feed displacements, resulting in a 1 Steradian half-power beamwidth. The proposed design could enable switchable and multi-beam transmitters, with broad-beam high-gain rectennas.