Broadband flexible rectifier with harmonic suppression network for wireless power transfer

This paper introduces a broadband flexible rectifier that employs a Class-F harmonic suppression network (HSN), designed for efficient long-distance wireless power transfer in applications such as solar power stations, wireless sensor networks, and unmanned aerial vehicles. The rectifier is notably compact, with dimensions of 24 × 18 mm2. The tapered transmission line is used for impedance matching, effectively bridging components with different impedances, reducing reflections, and broadening the operational bandwidth. The Class-F HSN further enhances power recovery efficiency. The rectifier is fabricated on a flexible polyimide substrate. It utilizes liquid metal EGaIn (a eutectic gallium-indium alloy with Ga and In mass fractions of 75.5% and 24.5%, respectively) in parallel with the HSMS-2860 Schottky diode for rectification. Experimental results demonstrate that the broadband flexible rectifier operates over a frequency range of 3.3–6.0 GHz, achieving a power conversion efficiency (PCE) of over 50% with a fractional bandwidth of 58.1%. In addition, at an input power of 13 dBm, the rectifier reaches a peak PCE of 61.7% and maintains a peak PCE of up to 59.5% even when bent.