55nm Ultra-Low-Power Local Oscillator for EPCglobal Gen2v2 Standardized Passive UHF RFID Tags
This paper deals with the development of an ultra-low-power local oscillator for use in passive UHF RFID tags. The oscillator is intended to provide the clock signal for digital processing and serves as the basis for generating the backscatter link frequency (BLF). The BLF must be adjustable depending on the reader query and be within specified tolerances to comply with the EPCglobal Gen2v2 standard. Besides the main requirement of the oscillator, an extremely low power consumption is essential. To meet this challenge, the design uses a current-starved, three-stage ring oscillator. Since the circuit is to be integrated in 55nm technology from Globalfoundries, this topology offers the advantage of not requiring passive components that would be difficult to integrate. To provide the bias voltages for the current-starving, a reference circuit is utilized. The results of the simulations show a low power consumption of about 381nW at an oscillation frequency of 5.82 MHz.