Description

Many packaging and structural materials are made of conductive materials such as metal or carbon-fiber composites, which limits the use of embedded radio frequency-based telemetry systems for sensing. In this paper, we present the design of a complete passive ultrasonic energy harvesting and back-telemetry system that exploits near-field acoustic coupling to wirelessly transfer energy and data across conductive barriers. The use of near-field operation makes the telemetry robust to multipath reflections that occur at barrier discontinuities and robust to crosstalk when multiple sensors are simultaneously interrogated.