A Multi-Phase Resonance-Based Boosting Rectifier with Dual Outputs for Wireless Power Transmission

A new multi-phase resonance-based rectifier (MPRR) capable of delivering a desired amount of power to two loads with large difference in their voltages is presented. This is particularly useful for wireless sensors/actuators, in which the MEMS needs a high voltage to operate but the interface circuitry requires a fraction of that. This is achieved by shorting the receiver LC-tank to increase its loaded Q-factor over several cycles to accumulate wirelessly transferred energy, then first break the loop in-phase, by connecting the LC-tank to the in-phase load to transfer energy at low voltage in a half-cycle, and then transfer energy to the quadrature load through a diode in a quarter-cycle at high voltage. By optimizing the number of cycles for in-phase charging, NI, and quadrature charging, NQ, the MPRR can achieve the highest power delivered to the load under a given set of design constraints. Governing equations in the MPRR operation are derived to identify the key specifications for the design procedure. Using an exemplar set of specifications, MPRR was able to generate 21.5V and 1.84V across 100k? and 200? loads, respectively, from a class-D power amplifier operating at 15V, 6.78MHz sinusoid input in the ISM-band at coil separation of 1.3cm.