A 2.3 pJ/bit frequency-stable impulse OOK transmitter powered directly by an RF energy harvesting circuit with −19.5 dBm sensitivity

The proposed 2.5-GHz-band impulse transmitter technology realizes frequency-stable impulse generation against PVT variation and superior energy-per-bit operation, and it can be powered directly from a - 19.5-dBm-sensitivity RF energy harvesting circuit without any regulators that are generally essential to power RF circuits. The transmitter occupies 0.38 mm
²
in a 65nm CMOS technology. The maximum frequency difference among measured output return-loss peak of 9 chips with 3 different process corners under 0.5 V supply is about 50 MHz without any frequency calibration. Our prototype achieves 1 Mb/s signal transmission under 2.3 μW power consumption from 0.5 V supply thanks to pulse-level duty cycling operation of maximally digital architecture.