A Wireless Passive Temperature Sensing Method for Cryogenic Applications

Abstract

As technology advances, temperature sensing is becoming a key issue in the cryogenic community. Key examples include the monitoring of aerospace equipment such as a spacecraft and the monitoring of automated production lines such as a cryogenic gas recovery plant. In such cryogenic environments, traditional temperature sensors are either inconvenient or complicated due to weak low-temperature tolerances and inaccessible working positions.To solve these problems, we propose a novel wireless passive temperature sensing method for cryogenic applications by only using low-temperature tolerant passive devices. By innovatively integrating a thermistor on a backscattering antenna, the temperature inside a cryogenic environment is transferred to a wirelessly obtainable return loss. In the measurement, the thermistor’s resistance changes with the temperature, which leads to an impedance mismatch between the antenna and the load. As a result, the sensor’s return loss is modulated by the temperature. The return loss is then wirelessly obtained by using a backscattering method, thus the temperature is derived.The purpose of this research is to propose a new sensing methodology, to monitor the temperature in a cryogenic environment wirelessly and passively.