A low-power RF front-end of passive UHF RFID transponders

Abstract

This paper presents in details the architecture and most of RF front-end building blocks of a fully integrated passive radio frequency identification (RFID) transponder operating at UHF 902MHz to 928MHz. A novel architecture for the transponder IC and a new low power on-off keying (OOK) demodulator are proposed in this paper. For realizing the system, a low power CMOS full-wave rectifier achieving a power conversion efficiency of 31.9% has been integrated in this transponder. Simulation results show that the global input power of front-end circuits is only about 21µw in order to drive a load of 1.8µA at the rectifier output and the power consumption of the proposed demodulator is less than 0.4µw. The transponder is fabricated in a 0.18µm mixed-mode CMOS technology and has the area of 0.70 mm2.

A digitally enhanced LDO voltage regulator for UHF RFID passive tags

“…The demodulator extracts the digital envelope from the RF link and recovers its logic voltage levels. Backscatter modulator receives digital data coming from the digital control and generates a proportional change in the reflection coefficient of the tag's antenna, [4,5,6,7].…”