UHF RFID with OCA tag for Short Range Communication

A UHF RF identification system, consisting of a fully integrated tag and a special reader, has been developed for short range and harsh size requirement applications. The system is fabricated in the standard 0.18μm CMOS process. The whole tag chip with antenna, analog front-end, baseband and memory, takes up an area of 0.36 mm2, which is smaller than other reported tags with on-chip antenna (OCA) using standard CMOS process. Self-defined protocol is proposed to reduce the power consumption, and minimize the size of the tag.

The specialized SOC reader system, consisting of RF transceiver, digital baseband, MCU and host interface, supports both self-defined and ISO 18000-6C protocol. Its power consumption is about 500mW, which is much lower than other reported readers considering the transmission power. Measurement results show that the system’s reading range is 2mm with 20dBm reader output power. Also, it has been verified that the data stored in the OCA tag embedded in a pearl can be successfully read out. With inductive antenna printed on paper substrate around the OCA tag, the reading range can be extended from several centimeters to meters depended on the shape and size of the inductive antenna.