Design of a passive UHF RFID transponder featuring a variation-tolerant baseband processor

This paper presents the design of a passive UHF RFID transponder in compliance with the ISO 18000-6C protocol operating at the 915MHz ISM band. The proposed tag IC is implemented with several advanced low-power techniques aiming at extending the range of communication. Since the on-chip oscillator is particularly sensitive to process, voltage and temperature (PVT) variations, the baseband processor is designed as a frequency variation-tolerant circuit in order to accommodate the fluctuation of the frequency from the local oscillator, which is anticipated to decrease the percentage of failed chips and enhance the performance of tags working in critical conditions. The tag chip is fabricated using Chartered 0.18¿m 1P6M standard CMOS process and occupies 0.54mm² area. And the minimum power to read the assembled transponder (connect the chip with a dipole antenna) is -11.4dBm.