Design of Dual-Band Inverse Class-F Rectifier for Wireless Power Transfer and Energy Harvesting

This letter presents a novel methodology for designing high-efficiency dual-band (DB) inverse class F (class \text{F}^{-1} ) rectifier for wireless power transfer (WPT) and energy harvesting (EH). Specifically, a proposed DB class \text{F}^{-1} harmonic termination network is employed based on transmission lines (TLINs) which are theoretically analyzed. The closed-form design formulas are derived for providing exact class \text{F}^{-1} harmonic manipulation at two arbitrary frequency bands, enabling a highly efficient DB class \text{F}^{-1} operation. For validation, a Schottky diode-based rectifier is implemented at two target frequencies of 1.9 and 2.45 GHz. The experimental results show that peak power conversion efficiency (PCE) can be achieved over 76\% at 1.81 and 2.35 GHz with an input power of 13 dBm. Moreover, the rectifier exhibits a >\!\!50\% PCE within a wide dynamic range (DR) of 19.5 and 17.5 dB at 1.81 and 2.35 GHz, respectively. To the author's best knowledge, this is the first time a DB diode-based rectifier design with the deployment of a DB harmonic termination mechanism is incorporated with a DB fundamental matching network.