A GaN-Based Lamb-Wave Oscillator on Silicon for High-Temperature Integrated Sensors

This letter presents the first fully integrated GaN-based Lamb-wave oscillator on Si substrate for high temperature operation. The 58 MHz oscillator prototype was implemented by monolithically integrating a two-port Lamb-wave delay line with electronics using AlGaN/GaN high electron mobility transistors (HEMTs). Electrical characterization from room temperature (RT) up to 250°C was performed on the open-loop Lamb-wave delay line device and the integrated oscillator. It is shown that this oscillator is able to deliver high output power (>11 dBm) up to 250°C. Over the temperature range from RT to 230°C, the oscillation frequency exhibits a linear dependence on temperature with a small temperature coefficient of frequency (TCF) of -47.5 ppm/°C. The frequency drift is less than 1%.