X-Band CMOS Rectifier With 4% Efficiency at −35 dBm for Wireless Power Transmission

This paper proposes a radio frequency (RF) rectifier topology for low-power wireless power transmission (WPT) applications in the X band. The rectifier consists of a biased PMOS pair and is matched to the RF signal source impedance using a PCB transmission line (TL) matching network. It is demonstrated that a clever optimization of the bias voltage enables the rectifier to achieve greater sensitivity and efficiency than previous works at X band. The rectifier was designed in a 45 nm silicon-on-insulator (SOI) process and operates at a frequency of 9.64 GHz. It achieves a power conversion efficiency (PCE) of 4% and 46% at power levels of −35 dBm and −10 dBm, respectively.