Dedicated antenna less power efficient OOK transmitter for mm-cubic IoT nodes

This paper proposes a compact VHF-band OOK transmitter that uses coils for radiation as well as oscillation, eliminating the need for an external antenna. This feature contributes to fewer number of components, smaller volume and and lower cost. We prototyped the transmitter with 2.8 mm × 2.8 mm × 4.2 mm volume. For shortening the startup time and enabling high-speed communication, we devise a scheme that provides a weak current for quick start of LC oscillation. Measurement results show that the start time of LC oscillation is reduced from 400 ns to 40 ns, and 1m communication at 3Mbps is possible. The minimum energy consumption per bit of the proposed transmitter is 205 pJ/b.