Characterization, Analysis and Optimization of a CMOS RF Energy Harvesting Rectifier System for WSN Application

Wireless Power Transfer has become an important aspect in energy harvesting to supply ultra-low power sensor networks. In remote areas, energy sources become a significant restriction for sensors. This paper presents an analysis and optimization technique for RF Energy harvesting system for Wireless Local Area Network (WLAN) source operating at 2.4GHz to power sensor node applications. The rectifier which is the main component for energy conversion features a multi-stage cross-coupled differential-drive architecture with single-sided biasing and storage capacitors on each stage to help improve the rectifier performance by adding instantaneous RF voltage at each stage. The architecture is implemented in standard 65nm CMOS Technology. The measurements were done by using input RF signal frequency of 2.4GHz for resistive load values of 30k, 100k and 1M Ohm. The proposed design system verification is used to analyze and investigate the effect and importance of layout and package parasitic impedances to the rectifier output voltage, sensitivity, and power conversion efficiency (PCE). Measurement results of
$\boldsymbol{\text{Rload}=100\mathrm{k}\Omega}$
and
$\boldsymbol{\mathbf{Cload}=10\text{pF}}$
showed an output voltage of 1 V at −10dBm input power and 23.93% PCE.