High-Temperature Fully Integrated Wireless Monitoring Systems for Aerospace Applications

This paper presents a fully integrated data transmission system utilizing gallium nitride (GaN) high-electron-mobility transistors (HEMTs). The system is specifically designed for high-temperature (HT) applications, with a focus on pressure and temperature sensors for aerospace purposes where the environmental temperature can surpass 400 °C. The proposed system comprises a front-end amplifier with a gain of 20 V/V to amplify the sensed signal, followed by a novel analog-to-digital converter (ADC) that drives a modulator employing the load-shift keying technique. An oscillation frequency of 1.5 MHz is employed to ensure robust wireless transmission, even through metallic barriers. To retrieve the data, a new demodulator architecture based on a half-bridge rectifier is introduced. The fabricated system is implemented on an 11 mm ² silicon carbide (SiC) substrate and experimentally validated at a temperature of 25 °C, while certain digital core circuits demonstrate stable operation at HT conditions up to 400 °C.