An Efficient Wireless Power Transmitter Based on Companded OFDM Signals

In this work, a waveform design using a combination of OFDM and companding technique is proposed to improve the wireless power transfer (WPT) efficiency without sacrificing the wireless information transfer performance. Employing a Simultaneous Wireless Information and Power Transfer (SWIPT) scheme called Power Splitting (PS) protocol, the transfer of power and data is achieved simultaneously between a Power Beacon (PB) and a receiver node. Furthermore, in order to capture all important nonlinear behaviors of a real energy harvester rectifier circuit, a curve fitting-based nonlinear rectifier model is used. Results show that the use of this companding technique allows the power amplifier (PA) to generate and transmit signals for WPT in a more efficient way, improving also the conversion efficiency of the energy harvester.