A 433-MHz Compact Inverse Class-F Rectifier for Biomedical Wireless Power Transmission
Dang‐An Nguyen, Gia Thang Bui, Hyungseok Nam, Yanghyun Kim, Chulhun Seo
Abstract
This letter presents a novel implementation of inverse class-F (class- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{F}^{-1}$ </tex-math></inline-formula> ) rectifier based on lumped elements for biomedical wireless power transfer (WPT) at 433 MHz. Specifically, in order to reshape the diode current and voltage according to the class- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{F}^{-1}$ </tex-math></inline-formula> waveform, a parallel LC resonator is deployed at the diode anode as a band-stop filter to provide infinite impedance for the second harmonic. Meanwhile, the third harmonic is terminated with zero impedance by a series LC network at the diode cathode side where its quality factor is also controlled to facilitate the fundamental matching. A prototype is fabricated and measured for verification showing that the peak power conversion efficiency (PCE) is achieved at 72.8% with an input power of 5 dBm. Also, the proposed rectifier exhibits <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text {PCE}>50\% $ </tex-math></inline-formula> within a wide dynamic range of 22.5 dB and a compact size of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$13\times 7$ </tex-math></inline-formula> mm2, which indicates an advantageous performance over the other existing designs with similar diode and frequency.