Narrowband and Wideband Dual-Mode Wireless Power Transfer System With a Single Transmitter

This study introduces a dual-mode wireless power transfer system for multistandard wireless charging products. The system allows two receivers to operate concurrently at narrowband and wideband frequencies using the proposed sinusoidal pulse width modulation (SPWM). Conventional SPWM does not provide independent control of switching and sideband harmonics, which are required for dual-mode excitation. We propose a new hybrid carrier and reference phase shift method to provide independent control of the reference, switching, and sideband harmonics. A prototype has been developed to validate power transfer at both narrowband (951 and 1190 kHz) and wideband (100 and 1190 kHz) frequency operations.