A 1.9GHz RF Transmit Beacon using Environmentally Scavenged Energy

Shad Roundy, Brian P. Otis, Yuen-Hui Chee, Jan M. Rabaey, Paul Wright
IEEE Int.Symposium on Low Power Elec. and Devices

The design and implementation of a 1.9GHz radio frequency transmit beacon is presented. The beacon is completely self contained, and all necessary energy is scavenged through solar and vibrational energy sources. Custom RF integrated circuitry and energy scavenging devices are used to create a highly integrated and efficient beacon. The 1.9GHz direct modulated transmitter uses a micromachined resonator and requires no other external components, inductors, or crystals. The beacon achieves duty cycles up to 100% for typical ambient solar conditions and 2.6% for typical ambient vibrational conditions.