A High-Sensitivity Temperature/Strain Sensor Based on a Single-Port SAW Resonator Featuring On-Chip Compensation Capability

we reported a surface acoustic wave (SAW) temperature/strain composite sensor, which was capable of exciting three modes. Based on multiple modes, an on-chip strain/temperature compensation scheme was proposed. We conducted tests at 25–120 °C and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0-800 \ \mu\varepsilon$</tex>. For temperature sensing, the cross sensitivity caused by strain is reduced to below 1.47%, and the maximum temperature deviation is 4.7 °C. For strain sensing, we further validated effectiveness at 120°C, and the measured strain agreed well with the reference strain, with a maximum relative error of 4.9%. Additionally, the sensitivity was <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$506.5 \text{Hz}/\mu\varepsilon$</tex> at 25°C, which was 3.6 times that of the traditional SAW strain sensor.