  In this paper, a highly-efficient single-switch-regulated resonant wireless
power receiver with hybrid modulation is proposed. To achieve both high
efficiency and good output voltage regulation, phase shift and pulse width
hybrid modulation are simultaneously applied. The soft switching operation in
this topology is achieved by the cycle-by-cycle phase shift adjustment between
the input current and the gate drive signal and also attributed to the reactive
components such as the series-compensated secondary coil and the parasitic
capacitor of the active switch . The soft switching operation also leads to
high efficiency and low EMI. By adjusting the duty ratio of the switch, tight
regulation of the output voltage can be attained. The steady-state and dynamic
models of the resonant receiver with hybrid modulation are analytically derived
in order to properly design the feedback controller. An experimental setup of a
two-coil wireless power transfer system, including the hardware prototype of
the proposed receiver, is constructed for experimental verification. The
experimental results show the effectiveness of the soft-switching operation in
the receiver with high efficiency while maintaining good regulation of the
output voltage, regardless of line and load variations.
