Arbitrary power and positioning techniques for 2D wireless power transmission systems

An arbitrary power and positioning two-dimensional (2D) wireless power transmission system is proposed and evaluated. A transmitter outputs the power to an arbitrary position on a 2D waveguide sheet by using multiple output ports. The output power and phase of each port is tunable. Power amplifier (PA) efficiency was improved from 19% to 46% when the output power was 10 dB smaller than peak power due to the use of a PA supply-voltage control scheme. The peak PA efficiency was 60%. A receiver inputs a wide range of power levels and drives various load impedances with a parallel rectifier. This rectifier allows a number of rectifying units to be tuned dynamically. The rectifier efficiency was improved one and a half times while expanding the input power range by 6 dB and extending the load impedance range fourfold. The rectifier efficiency was 66-73% over an input power range of 18-36 dBm at load impedances of 100 and 400 Ω.