An RF Energy Harvester System Using UHF Micropower CMOS Rectifier Based on a Diode Connected CMOS Transistor

Table 1

A comparison of this work with previous works.

References	This work	[7]
CMOS technology node	180 nm	90 nm	250 nm	350 nm	250 nm	300 nm	500 nm	180 nm
Typical threshold voltage	0.51 V	0.45	0.55		0.15	0.53	0.2	0.15
Operating frequency	900 MHz	915 MHz	906 MHz	953 MHz	450 MHz	950 MHz	869 MHz	900 MHz
Additional requirement	Deep n-well	Deep n-well	Precharge phase is needed		Low Vth transistor	Auxiliary battery is needed	Schottky diode	Low Vth transistor
Minimum RF input power	−9 dBm; (on-chip inductor); −18 dBm; (off-chip inductor)	−18.83 dBm	−17.9 dBm	−9 dBm	−18.6 dBm	−14 dBm	−20.1 dBm
Rectifier efficiency at minimum RF input power	14.46%; (on-chip inductor); 18.08%; (off-chip inductor)	11%	9.2%	15.4%	10.4%	1.5%	14.5%	12.6%
Maximum achievable efficiency	58.2%; (on-chip inductor); 81.75%; (off-chip inductor)							40%
Number of stages	5	24						24