A Microwave Temperature Sensor Based on Complementary Finger Split-Ring Resonator Near-Field Resonance Induction

Based on the near-field multi-resonance sensing characteristics of microwave complementary finger split-ring resonator (CFSRR) and the thermal strain displacement response characteristics of metal, a multi-resonance response microwave temperature sensor with temperature information response and temperature information generation isolated from each other is proposed. By introducing a high-temperature resistant ceramic shell (HTRCS) and a metal thermal sensing expansion branch (MTSEB), the proposed sensor is highly immune to interference. Its theoretical temperature measurement limit is adjustable solely by the heat resistance of the temperature sensing probe itself. The analysis results show that by introducing MTSEB with stainless steel, the proposed temperature sensor is endowed with a theoretical potential temperature measurement limit of 1200°C. Meanwhile, through the preparation and measurement of the proposed temperature sensor, it is indicated that the proposed temperature sensor has an average temperature sensing resolution of 0.514MHz/°C and 0.572MHz/°C under temperature multi-resonance sensing within the test temperature range of 725°C. The experimental test results confirmed the feasibility of the proposed sensor. Considering the good embedded integrated capability, it is predictable that it will be endowed with great application potential in temperature sensing of industrial devices with complex working conditions.