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Review of Research Status and Development Trends of Wireless Passive LC Resonant Sensors for Harsh Environments.

Li C, Tan Q, Jia P, Zhang W, Liu J, Xue C, Xiong J - Sensors (Basel) (2015)

Bottom Line: Measurement technology for various key parameters in harsh environments (e.g., high-temperature and biomedical applications) continues to be limited.Consequently, these devices have become the focus of many current research studies.The advantages and disadvantages of various sensor types are discussed, and prospects and challenges for future development of these sensors are presented.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Instrumentation Science & Dynamic Measurement, Ministry of Education, North University of China, Tai Yuan 030051, China. flanklichen@163.com.

ABSTRACT
Measurement technology for various key parameters in harsh environments (e.g., high-temperature and biomedical applications) continues to be limited. Wireless passive LC resonant sensors offer long service life and can be suitable for harsh environments because they can transmit signals without battery power or wired connections. Consequently, these devices have become the focus of many current research studies. This paper addresses recent research, key technologies, and practical applications relative to passive LC sensors used to monitor temperature, pressure, humidity, and harmful gases in harsh environments. The advantages and disadvantages of various sensor types are discussed, and prospects and challenges for future development of these sensors are presented.

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Related in: MedlinePlus

Principles and equations for wireless sensor measurements.
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sensors-15-13097-f002: Principles and equations for wireless sensor measurements.

Mentions: The lumped circuit model of a wireless passive LC sensor is equivalent to an LC circuit, where C is the sensitivity capacitance (Figure 2). The resonant frequency of a sensor drifts according to variations in the measured parameters (e.g., temperature, pressure, and humidity). When the swept-frequency signal generated by the measurement antenna passes over the resonant frequency of the sensor, the impedance characteristics (such as phase and magnitude) as seen by the antenna can be extracted because of the coupling link between the measurement antenna and the sensor. Thus, wirelessly measuring the resonant frequency of the sensor becomes possible. Figure 2 shows the process of performing wireless sensor measurements: fs is the sensor resonant frequency, and fmin is the frequency of the lowest point of the phase angle as seen by the measurement antenna [8].(1)fmin=fS(1+k24+18Q2)where k is the coupling coefficient between the inductance coils of the antenna and the sensor, and Q is the quality factor of the sensor. If k is sufficiently low and Q is sufficiently high, the resonant frequency of the sensor in a harsh environment can be determined by monitoring the variation in fmin. Thus, the sensor is an LC resonant circuit with variable capacitance that can wirelessly communicate with an external measurement antenna.


Review of Research Status and Development Trends of Wireless Passive LC Resonant Sensors for Harsh Environments.

Li C, Tan Q, Jia P, Zhang W, Liu J, Xue C, Xiong J - Sensors (Basel) (2015)

Principles and equations for wireless sensor measurements.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4507668&req=5

sensors-15-13097-f002: Principles and equations for wireless sensor measurements.
Mentions: The lumped circuit model of a wireless passive LC sensor is equivalent to an LC circuit, where C is the sensitivity capacitance (Figure 2). The resonant frequency of a sensor drifts according to variations in the measured parameters (e.g., temperature, pressure, and humidity). When the swept-frequency signal generated by the measurement antenna passes over the resonant frequency of the sensor, the impedance characteristics (such as phase and magnitude) as seen by the antenna can be extracted because of the coupling link between the measurement antenna and the sensor. Thus, wirelessly measuring the resonant frequency of the sensor becomes possible. Figure 2 shows the process of performing wireless sensor measurements: fs is the sensor resonant frequency, and fmin is the frequency of the lowest point of the phase angle as seen by the measurement antenna [8].(1)fmin=fS(1+k24+18Q2)where k is the coupling coefficient between the inductance coils of the antenna and the sensor, and Q is the quality factor of the sensor. If k is sufficiently low and Q is sufficiently high, the resonant frequency of the sensor in a harsh environment can be determined by monitoring the variation in fmin. Thus, the sensor is an LC resonant circuit with variable capacitance that can wirelessly communicate with an external measurement antenna.

Bottom Line: Measurement technology for various key parameters in harsh environments (e.g., high-temperature and biomedical applications) continues to be limited.Consequently, these devices have become the focus of many current research studies.The advantages and disadvantages of various sensor types are discussed, and prospects and challenges for future development of these sensors are presented.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Instrumentation Science & Dynamic Measurement, Ministry of Education, North University of China, Tai Yuan 030051, China. flanklichen@163.com.

ABSTRACT
Measurement technology for various key parameters in harsh environments (e.g., high-temperature and biomedical applications) continues to be limited. Wireless passive LC resonant sensors offer long service life and can be suitable for harsh environments because they can transmit signals without battery power or wired connections. Consequently, these devices have become the focus of many current research studies. This paper addresses recent research, key technologies, and practical applications relative to passive LC sensors used to monitor temperature, pressure, humidity, and harmful gases in harsh environments. The advantages and disadvantages of various sensor types are discussed, and prospects and challenges for future development of these sensors are presented.

Show MeSH
Related in: MedlinePlus