关键词: 气体传感器, 复合异质结, 微波检测, 丙酮

Abstract: To address the issue of traditional gas sensors requiring high-temperature heating for gas detection, a microwave sensor based on a spiral structure was designed, generating an independent transmission zero at the 2.8 GHz frequency band. SnO₂-Co₃O₄ composite fibers were prepared using electrospinning and high-temperature calcination processes, and a novel microwave gas sensor was fabricated using a resonator structure. This sensor employs an n-p material composite heterostructure, enabling high-precision measurement of acetone in the range of 2.0-12.0 ×10^-5, with advantages such as simple operation, low cost, and miniaturization. Experimental results showed that at room temperature, the response of SnO₂-Co₃O₄ composite fibers to 1.20 ×10^-4 acetone was reflected in the change of return loss, with a sensitivity of 3.28×10⁷ mdB and a harmonic amplitude variation of 3.28 dB. This research provides a new solution for low-concentration, high-precision gas detection in industrial and laboratory settings.

Key words: gas sensor, composite heterojunction, microwave detection, acetone