High-Efficiency Microwave Rectifier With Extended Operating Bandwidth

This brief presents a microwave rectifier using a novel impedance matching technique to extend the operating bandwidth. Originated from the impedance control at two separated frequencies, the matching network is capable of manipulating the impedance over a wide frequency band by three steps. In this way, the operating bandwidth is extended. Theoretical analysis is carried out and closed-form design equations are derived. For validation, a wideband rectifier is implemented operating at 0.57-0.90 GHz at the input power of 12.8 dBm. It exhibits the fractional bandwidth of 44.9% for RF-dc conversion efficiency of higher than 70%. Moreover, the rectifier keeps more than 50% efficiency within 0.57-0.90 GHz at the input power from 3 dBm to 14.1 dBm.