A −30 dBm sensitive ultra low power RF energy harvesting front end with an efficiency of 70.1% at −22 dBm

Abstract

A high Q matching network is being proposed for an RF energy scavenging system that is highly efficient and ultra low power sensitive. The applications of the presented technique are passive next generation wearable devices for remote health care monitoring systems and wireless sensor nodes with usual input power ranging from 1μm to 100μW from 4W EIRP source. The rectifier can rectify an equivalent input voltages as low as 10mV from antenna and is ultra low power sensitive with 1μW(−30 dBm) rectifying capability. The proposed RF energy harvesting scheme achieves better rectifier efficiency of 70.1% at −22 dBm input power (30m distance from 4W EIRP source) compared to existing schemes in literature at 953-MHz to drive load resistance 226KΩ,. The proposed high Q matching technique achieves a better drive strength as it is capable to drive higher load. The RF energy harvesting system is implemented in a standard UMC 0.18μm CMOS technology and generates 1 V regulated output voltage. The results are verified using schematic and post layout simulations.