Highly efficient multistandard RFIDs enabling passive wireless sensing

This paper presents a highly efficient analog multistandard frontend for passive sensor-enabled RFID transponders. The CMOS only frontend is implemented in a 0.13 ¿m CMOS technology. The measured overall RF-to-DC power conversion efficiency of the analog frontend for a DC output power of 10 ¿W is about 7% and the maximum efficiency is about 15% at UHF. An implemented sensor interface consumes 1.4 ¿A at 1V supply. This interface contains an ultra low-power successive approximation ADC that uses the capacitive charge redistribution technique for its integrated DAC.