Wireless Power Transfer Using Chirp Waveforms

In this work, we investigate a superimposed chirp waveform for wireless power transfer (WPT) applications. By taking into account the properties of chirp signals, a transmission scheme is proposed that incorporates chirp superposition and subband selection to exploit both diode’s nonlinearity and frequency diversity. Novel closed-form expressions of the average harvested energy (HE) at the receiver are derived by considering tools from order statistics. Through analytical and numerical results, we prove that superimposed chirp-based WPT improves the HE level of about 30%, and extends the operating range of energy transfer compared to conventional fixed-frequency waveforms.