Predicted and measured temperature compensated surface acoustic wave devices for high-temperature applications

Abstract

Industrial monitoring and process control, power plants, aerospace industry, military equipment manufacturing, oil and gas industries are examples of businesses in need for high-temperature and harsh-environment electronic components and systems. In particular, resonators and filters that operate beyond the 125°C military range upper limit, normally dictated by silicon-based semiconductor devices, are required in applications which demand frequency control, clocking and sensors. In this Letter, temperature compensated surface acoustic wave orientations appropriate for the fabrication of resonators and filters >125°C have been identified through numerical calculations and experimentally confirmed on a commercially available langasite wafer, a piezoelectric crystal which operates at high temperatures. Resonator filters have been designed, fabricated and tested along two orientations, confirming the zero temperature sensitivities at 150 and 300°C. These devices are of great interest for modern harsh environment frequency control, timing and sensor applications.