AN INTERMODULATION RECYCLING RECTIFIER FOR MICROWAVE POWER TRANSMISSION AT 2.45 GHz

The microwave to direct current (MW-DC) conversion efficiency of a rectifier drops significantly in a dual-frequency microwave power transmission (MPT) system. The measured data show that the MW-DC efficiency of a rectifier drops from 67% to 53% when the microwave source is switched from a continuous wave to a dual-tone waveform at the same power level. It is mainly due to the intermodulation effects resulted from a nonlinear component, e.g., the diode, in a rectifier. A novel rectifier is designed to improve the MW-DC efficiency by recycling the intermodulation power besides the harmonic power. With the novel configuration, the maximum MW-DC conversion efficiency of 62% can be achieved for a dual-tone waveform input at 17 dBm. It implies that more than one half of the intermodulation power has been recycled to DC power.