A dual-channel UHF passive CMOS RFID tag design

This paper presents a highly efficient 15-bit UHF passive radio-frequency-identification (RFID) tag chip. The tag operates at dual bands: 866.4 MHz/2.45 GHz or 925 MHz/2.45 GHz. The power-link uses low band (866.4 or 925 MHz) and the data-link uses high band (2.45 GHz). Neither a VCO nor a regulator is included in our design. A novel decoder circuit for the pulse-interval encoding (PIE) symbol is presented. The conversion efficiency of RF to dc power is around 30%. The lowest RF power that our tag can work is -21.86 dBm. Our RFID tag chip is implemented in TSMC 0.18 μm 1P6M CMOS technology. Its area is 0.958×0.931 mm
²
.