Development of High Temperature Wireless Sensor Technology Based on Silicon Carbide Electronics

Smart Sensor Systems that can operate at high temperatures are required for a range of aerospace applications including propulsions systems. This paper discusses the development of a high temperature wireless system that includes a sensor, electronics, wireless communication, and power. In particular, a wireless pressure sensor was demonstrated at 300°C, with signal transmission over one meter distance and power derived from scavenged energy. The circuit had a nominal oscillation frequency of near 100 MHz and used a commercial SiC metal semiconductor field effect transistor (MESFET) together with metal-insulator-metal (MIM) capacitors and a thin film inductor/antenna. With the sensor and oscillator circuit at temperatures from 25 to 300°C, the oscillator frequency, detected at a distance of one meter, was found to vary repeatably as a function of pressure. This work is considered a foundation for the development of higher temperature Smart Sensor Systems for use in harsh environments.