An Integrated Battery-Less Wirelessly Powered RFID Tag with Clock Recovery and Data Transmitter for UWB Localization
In this paper, we present a fully integrated battery-less RFID tag that is fabricated in 180nm CMOS technology for localization and biomedical applications. The design is composed of a rectenna, a power management unit, a data receiver used for clock recovery, and a UWB transmitter. Power and clock signals are transferred to the tag through an inductive link at 250 MHz that is AKS-modulated with a square wave with a frequency of up to 2 MHz. The proposed tag can be used as a transponder to transmit back short pulses with a width of 50 ns when placed in proximity of a reader. Measured results show that the tag can also be used for communication purposes and communicate a sequence of digital data to a reader. The whole chip size including a loop antenna for power and clock recovery and a dipole antenna for the UWB transmitter is 2.4 × 2.3 mm².