A wirelessly powered injection-locked oscillator with on-chip antennas in 180nm SOI CMOS

This paper presents a battery-less mm-sized wirelessly powered injection-locked oscillator with on-chip antennas in 180nm SOI CMOS. The chip harvests electromagnetic radiation from a continuous-wave source in the X-band using an on-chip antenna. In addition, the chip is equipped with a broadband injection-locking oscillator that locks to the frequency of the input and produces a synchronized signal at the half frequency of the input. The new signal is then radiated back using an on-chip dipole antenna. This architecture resolves the conventional self-interference issue in RFID sensors by separating the received and transmitted frequencies. In addition, the locking mechanism improves the phase-noise of the on-chip oscillator to −93dBc/Hz at 100Hz offset.