Microwave Sensors and Their Applications in Permittivity Measurement

• Published in: Sensors (Basel, Switzerland) Vol. 24; no. 23; p. 7696
• Main Authors: Liu, Changjun, Liao, Chongwei, Peng, Yujie, Zhang, Weixin, Wu, Bo, Yang, Peixiang
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01.12.2024; MDPI
• Subjects: Accuracy; Autonomous vehicles; Comparative analysis; Composite materials; cross-technology; Design; differential signals; Electric fields; Electric properties; Electromagnetism; Energy; Glucose; Integrated circuits; Materials science; Measurement; Medical research; metamaterials; Microfluidics; microwave sensor; permittivity measurement; Plastic pollution; Review; Sensors; Silicon wafers; Trends; algorithms; differential signals; cross-technology; microwave sensor; metamaterials; microfluidics; permittivity measurement
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s24237696

This paper reviews microwave sensors and their applications in permittivity measurement. The detection, diagnosis, classification, and monitoring without contact and invasion have been the subject of numerous studies based on permittivity characteristics tracking. This review illustrates many new types of research in recent years. Firstly, the application background is briefly introduced, and several main measurement methods are presented. An overview of measurement technology in various applications is compiled and summarized based on numerous typical examples. Exciting applications are compared and presented separately, combining resonator sensors with strong electric fields. Furthermore, differential signals represent trends for future applications with strong environmental immunity, an alternative option to expensive measuring equipment. With the alternation of metamaterials, microfluidics technologies, cross-technology, algorithms, and so on, sensors play an exceptionally prominent role in practical and low-cost applications.