A W-Band Pseudo-Differential CMOS Switching Rectifier for Wireless Power Transfer

This letter presents a W-band pseudo-differential CMOS switching rectifier for wireless power transfer (WPT). The transistor pair serves as switches to enable full-wave rectification, achieving enhanced power conversion efficiency (PCE) compared to conventional single-ended (SE) designs. To maintain phase-aligned ac waveforms between the gate and drain terminals, effective magnetic coupling is introduced by means of nested inductors while facilitating a compact layout floor-plan. Fabricated in a 40-nm bulk CMOS process, the proposed rectifier demonstrates the measured PCE exceeding 20% for input power between 10–18 dBm. The peak PCE reaches 35% with an optimal load of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$20~{\Omega }$</tex-math> </inline-formula> at 94 GHz. At 18-dBm input power, over 24% PCE is realized across 90–99 GHz. The core area is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$180\times 140~{\mu }$</tex-math> </inline-formula>m.