A Transistor-Based High-Efficiency Rectifier Using Input Second Harmonic Component

This paper presents a novel methodology for enhancing rectification efficiency through a transistor-based rectifier design. Here the input second harmonic component at the gate node is employed to modify the output drain current waveforms, thus having a positive effect on the rectification efficiency. A parameter is introduced to evaluate the input second harmonic component, while theoretical analysis is conducted using the class-F operation mode. Further, the relationships between rectification efficiency, drain current, and the input second harmonic component, power ratio, and conductance angle are theoretically derived in detail. Through the appropriate selection of the input second harmonic component, the rectification efficiency can be significantly enhanced. To validate the proposed strategy, a class-F rectifier based on a GaN transistor operating at 2.45 GHz is designed, fabricated, and tested. Measurement results demonstrate a peak rectification efficiency of 90.7% with a dc load of $87 \Omega $ and an input power of 40 dBm. The rectifier implemented here exhibits state-of-the-art performance for rectification efficiency compared to other transistor-based rectifiers.