An ultra low power ASK demodulator for passive UHF RFID tag

In this paper, an Amplitude Shift Keying (ASK) demodulator circuit for passive UHF Radio Frequency Identification (RFID) tag is designed with ultra low power. Full chip area of the tag is 0.38mm
²
@0.18μm CMOS process (without test pads) and consumes only 4.28μW. As a significant module of the tag, the proposed ASK demodulator is powered by on-chip power of only 0.95V and consumes ultra small average current of 0.23μA for typical 300mV RF input voltage. Meanwhile, the demodulator can also be powered from external pad, in which way the supply voltage can be as low as 0.5V with 0.21μA current consumption.