A dual-band(6.78/13.56 MHz) complementary metal-oxide-semiconductor(CMOS) rectifier integrated circuit(IC) for magnetic resonance wireless power transfer(MRWPT) systems is proposed in this study. The proposed rectifier is designed as a comparator-based active diode rectifier to minimize the losses caused by the threshold voltage of the metal-oxide-semiconductor field-effect transistor (MOSFET). The rectifier consists of two comparators: a self-biasing circuit block and cross-coupled PMOSFET s. The power conversion efficiency(PCE) of the rectifier was maximized by eliminating the reverse current of the comparator by controlling the on-off time of the active diode. The rectifier chip was fabricated following Samsung's 65 nm CMOS process. The results of the simulation showed that the PCE of the rectifier at 6.78/13.56 MHz increased up to 95.5 %.