A Temperature Compensated 61-W Class-E Soft-Switching GaN-Based Active Diode Rectifier for Wireless Power Transfer Applications

The proposed 6.78-MHz Class-E receiver features a soft-switching and temperature-compensated GaN-based active diode (GAD) rectifier design. Using the temperature dependence of the relationship between the driving voltage and the on-resistance of the switch, the gate-source control voltage of GaN can be adjusted to mitigate efficiency variations based on temperature effects. Moreover, a phase shift comparator activation controller is based on the direct relationship between the phase delay on the gate drive signals and the output power. The temperature dependency voltage offset of the comparator is alleviated with auto-zeroing. GAD rectifier ensures energy transfer up to 61 W and 6.8 A, high efficiency of 92%, and low harmonic distortion of 2.1%.