A Wide-input-range 918MHz RF Energy Harvesting IC with Adaptive Load and Input Power Tracking Technique

This paper presents a high-efficiency radio frequency (RF) power harvesting IC with an extended input range. The proposed system comprises a reconfigurable rectifier, maximum power point tracking unit, load modulation circuit, and low-dropout regulator. The reconfigurable rectifier extends the high-efficiency range of the RF input power through stage number control and load modulation according to input power and load requirements. The design is fabricated using $0.18-\mu \mathrm{m}$ CMOS technology, and the chip area is $1.15 \times 0.57\text{mm}^{2}$. The proposed system can achieve an RF-DC power conversion efficiency greater than 20% in a 16.5-dB input power range with a peak value of 45%, and sensitivity of -16 dBm for a 1-V output voltage.