Matching the Power, Voltage, and Size of Biological Systems: A nW-Scale, 0.023- ${\rm mm}^{3}$ Pulsed 33-GHz Radio Transmitter Operating From a 5 kT/q-Supply Voltage

This paper explores the extent to which a solid-state transmitter can be miniaturized, while still using RF for wireless information transfer and working with power densities and operating voltages comparable to what could be harvested from a living system. A 3.1 nJ/bit pulsed millimeter-wave transmitter, 300 μm by 300 μm by 250 μm in size, designed in 32-nm SOI CMOS, operates on an electric potential of 130 mV and 3.1 nW of dc power. Far-field data transmission at 33 GHz is achieved by supply-switching an LC-oscillator with a duty cycle of 10^-6. The time interval between pulses carries information on the amount of power harvested by the radio, supporting a data rate of ~ 1 bps. The inductor of the oscillator also acts as an electrically small (λ/30) on-chip antenna, which, combined with millimeter-wave operation, enables the extremely small form factor.