Design of Regulated Voltage Supply Circuit for Passive RFID Tag

This paper presents the design of a regulated voltage supply circuit for a passive UHF RFID tag, which contains a matching network for maximum power delivery, a rectifier, and a voltage regulator. The proposed rectifier overcomes the limitations of conventional rectifiers by achieving both high power conversion efficiency and high output voltage. The circuit achieves 38% power conversion efficiency at 920 MHz, -21 dBm input power, and 1M DC output load. The -21 dBm threshold power improves efficiency and reduces total power consumption, which extends the communication range. The short operating distance of RFID technology has limited its application range in other fields. The theoretical equations and design techniques of the proposed regulated voltage supply circuit are presented and validated with simulation results in a 90 nm CMOS process.