A CMOS Rectifier Employing Body Biasing Scheme for RF Energy Harvesting
Munir A. Al-Absi, Ibrahim M. Alkhalifa, Adel A. Mohammed, Abdulaziz Al-Khulaifi
Abstract
This paper presents a CMOS rectifier for RF energy harvesting. The structure of the proposed design is based on a modified cross-coupled architecture. It employs an adaptive body biasing technique to lower the transistor threshold voltage (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> ) when the PMOS is ON. This would increase the conduction current. Moreover, this technique increases V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> when the PMOS is OFF. This would minimize the current flowing in the reverse bias condition. The proposed design is simulated using 0.18 μm TSMC CMOS technology under various loading conditions and an input frequency of 953 MHz. A peak power conversion efficiency (PCE) of 78.2% is achieved at an input power of -27.5 dBm and a 100 kΩ load.