Design of a Rectifier-Free UHF Gen-2 Compatible RFID Tag using RF-Only Logic

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  • Author: Wenxu Zhao, Kirti Bhanushali, and Paul Franzon, North Carolina State University

AC-DC rectifier and storage capacitors take up 25% or more of chip area for cost-sensitive passive RFID tags. In this work, we show that these components can be eliminated by utilizing a RF-only circuit structure. Therefore, the chip would be smaller and cheaper. RF-only logic permits digital operations to be performed from an AC, rather than DC, power supply. An UHF Gen-2 compatible RFID tag is designed using the RF-only logic. Powering and communication solutions in direct ASK carrier powered scenario are developed. RF front-end circuits are designed in RF-only fashion and a standard cell library of RF-only logic is developed and tailored for this application. The RFID tag is implemented in a 0.13 µm CMOS technology. The tag dimensions are 0.6 mm × 0.3 mm and its sensitivity is 0 dBm in simulation.