An Automatic Matching High-sensitivity RF Energy Harvesting System with Tuning Power Consumption of 2.4 nW

This brief presents a fully integrated automatic impedance-matching RF energy harvesting system that automatically compensates for variations at the antenna-rectifier interface. The control loop is fully integrated on-chip with a low-voltage, low-power design. The design is fabricated in 0.18-μm CMOS technology, and the active chip area is 0.064 mm2. The sensitivity optimized by impedance tuning can be improved to more than -30.5 dBm for 0.7 V output at varied initial mismatches, leading to a maximum increase in sensitivity of 5 dB. The control circuit's power consumption is only 2.4 nW, and the minimum supply voltage is 416 mV.