Microwave wireless high temperature sensor based on metamaterials

Abstract

The present application relates to the technical field of sensor, in particular to a kind of microwave wireless high temperature sensor based on super material, including the super material array unit of receiving array, the feed network unit of electromagnetic signal output and the introduction of the thermistor unit, in the working process, wave absorber array first captures electromagnetic signal sent by inquiry antenna, subsequently captured electromagnetic signal is output to the end of the thermistor unit loaded by the feed network unit.This time, platinum resistance with different characteristics will produce electromagnetic reflection of different intensity, and finally be fed back to inquiry antenna by wave absorber array, so as to realize temperature monitoring and measurement to the internal environment of closed cavity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sensors, and in particular to a microwave wireless high-temperature sensor based on metamaterials. BACKGROUND

[0002] Temperature measurement has always been an important part of human health research, chemical production, energy transportation and aerospace activities. Especially with the rapid development of industrial technology, chemical production, energy transportation and aerospace activities are developing towards higher temperature, more complex systems and higher value. Therefore, the development of temperature sensors with higher environmental adaptability, more simplicity and higher measurement capability to realize the operation temperature measurement, process monitoring, process control, safety warning and related scientific research of complex environment, high temperature and high pressure chemical reaction furnace, high temperature and high pressure hot flow pipeline and other systems puts forward new requirements.

[0003] The temperature measurement methods for complex environments and industrial high temperature and high pressure reaction furnaces, high temperature and high pressure hot flow pipeline systems and devices mainly include thermal infrared feature temperature measurement, thermocouple temperature measurement, optical fiber temperature measurement and microwave induction resonance temperature measurement. For thermal infrared temperature measurement, the temperature information of the system / environment to be measured is obtained by acquiring the thermal radiation characteristics, which has the ability to quickly acquire temperature distribution information of a wide test plane. However, this method is usually suitable for open test space, and temperature compensation is needed for closed systems, making it difficult to directly measure the internal temperature of the system. As the most common industrial temperature measurement method, thermocouple temperature measurement uses the temperature excitation of the test probe in the test environment to cause a potential difference, and the temperature is measured by acquiring the potential difference information. It has the characteristics of wide temperature measurement range (currently up to about 2000K) and high temperature measurement accuracy, but it needs to be connected by wire, and in the measurement of extreme high temperature environment, a complex cooling system is often needed. Optical fiber temperature measurement is a method in which the optical fiber test probe changes its structure under the action of the test environment temperature, so that the optical properties of the optical signal such as light intensity, wavelength, frequency, phase, polarization state, etc. change, and then the measured parameters are obtained through the corresponding modulator to obtain the temperature information. Its characteristics are low signal energy (non-electrical signal) during testing, safe testing, but it also has the problem of difficulty in monitoring and measuring the internal environment temperature of closed devices and systems. With the development of microwave technology, research on temperature measurement based on microwave devices has entered people's field of vision. Microwave temperature measurement is a method in which the temperature signal causes the test probe to change its structure, displacement and stretching, and then the structure change of the probe is converted into the change of the microwave transmission characteristics to realize the temperature measurement. Due to the good spatial transmission characteristics of microwaves, microwave temperature sensors can realize wireless signal connection, making the temperature sensor further simplified.

[0004] To this end, many microwave wireless temperature sensors are proposed, which are realized by near distance capacitive-inductive coupling, using interrogation antennas (such as rectangular waveguide, patch antenna) to realize the resonance characteristic mutation information caused by the structure change of the temperature measuring probe caused by temperature, and then obtain the temperature of the test environment; secondly, through the coupling and integration design of the response antenna (double antenna) and the temperature measuring probe, the important means is to realize the microwave resonance temperature measurement at a long distance. However, from the characteristics of microwave wireless transmission, whether it is near distance capacitive-inductive coupling temperature measurement or long distance antenna integrated coupling temperature measurement, their signal transmission paths ultimately need to be open to different degrees of space to be realized. Therefore, for the above current microwave temperature measurement technology, although they solve the problems of wireless connection of the sensor and high environmental adaptability, it is still difficult to realize the effective measurement of the internal environment temperature of the high temperature and high pressure closed cavity. Therefore, in order to further improve the universality of the microwave resonance temperature sensor, further research on the microwave sensor is needed. SUMMARY

[0005] The purpose of the present application is to provide a microwave wireless high temperature sensor based on metamaterial, which can realize real-time measurement, temperature monitoring and safety warning of temperature in complex environment and high temperature and high pressure industrial devices working in complex environment.

[0006] To achieve the above purpose, the present application provides a microwave wireless high temperature sensor based on metamaterial, which comprises a temperature sensor module, a rectangular waveguide interrogation antenna module and a vector network analyzer module. The rectangular waveguide interrogation antenna module is the actual transceiver front end of the measurement signal, which radiates and receives microwave signals. The vector network analyzer module is used for analyzing, judging and acquiring important roles of temperature signals in the temperature measurement and monitoring process.

[0007] The temperature sensor module comprises a metamaterial array unit, a feed network unit and a thermistor unit. The metamaterial array unit is used to receive electromagnetic signals emitted by the interrogation antenna and radiate echo signals from the load back to the interrogation antenna. The feed network unit outputs the electromagnetic signals captured by the metamaterial array unit through metallized via holes, and realizes the feed of the thermistor unit through coaxial output structure.

[0008] The metamaterial array unit is composed of 8*8 metamaterial units.

[0009] The feed network unit can also output the electromagnetic signals reflected from the load to the metamaterial array in reverse, to feedback the measurement information.

[0010] The heat-sensitive platinum resistance unit is a coaxial structure heat-sensitive load, the heat-sensitive load is connected to the output end of the power supply network unit, and the heat-sensitive load is excited by different ambient temperatures to generate different impedance characteristics, so that the microwave signal from the power supply network generates a signal reflection of different intensities to characterize the temperature information of the test environment through the electromagnetic echo signal.

[0011] The coaxial structure is a ceramic filling structure.

[0012] The microwave wireless high-temperature sensor based on the metamaterial is based on the perfect electromagnetic wave absorption characteristics of the electromagnetic metamaterial under good impedance matching, and the electromagnetic signal receiving array unit, the electromagnetic signal output feeding network unit and the heat-sensitive platinum resistance unit are designed, in the working process, the wave absorber array first captures the electromagnetic signal emitted by the interrogation antenna, then the captured electromagnetic signal is output to the load heat-sensitive platinum resistance unit through the feeding network unit. At this time, the platinum resistance with different characteristics will produce electromagnetic reflection of different intensities, and finally be fed back to the interrogation antenna by the wave absorber array. Since the heat-sensitive platinum resistance is extremely sensitive to temperature, different degrees of echo signal represent different measurement temperatures, so the echo signal of the wave absorber array obtained through the interrogation antenna can obtain the temperature information of the test environment / device, and finally complete the wireless temperature measurement. In addition, since the test probe end (platinum resistance) is a coaxial structure, the size and volume of the structure can be customized, and the characteristics are small, so that embedded integrated design can be realized, so as to realize temperature monitoring and measurement of the internal environment of the closed cavity. It can be seen that the proposed microwave temperature sensor not only has wireless temperature measurement capability, but also has temperature measurement and monitoring capability for closed high-temperature and high-pressure devices / environment; in addition, the integrated design endows the sensor with more compact and portable characteristics. BRIEF DESCRIPTION OF DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced.

[0014] Figure 1 is a structure diagram of a temperature sensor module of a microwave wireless high-temperature sensor based on the metamaterial of the present application.

[0015] Figure 2 is a schematic diagram of a metamaterial array unit of a microwave wireless high-temperature sensor based on the metamaterial of the present application.

[0016] Figure 3 is a schematic diagram of a feeding network unit of a microwave wireless high-temperature sensor based on the metamaterial of the present application.

[0017] Figure 4is a microwave detection result diagram of a microwave wireless high temperature sensor of a microwave wireless high temperature sensor based on metamaterials under different impedance characteristic loadings of the present application.

[0018] Figure 5 is a microwave detection result diagram of a microwave wireless high temperature sensor of a microwave wireless high temperature sensor based on metamaterials under different temperature excitations of the present application.

[0019] 101 - Metamaterial array unit, 102 - Feed network unit, 103 - Thermistor unit. DETAILED DESCRIPTION

[0020] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, the embodiments described below by reference to the accompanying drawings are exemplary, and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0021] Please refer to Figures 1 to 5 , Figure 1 is a structure diagram of a temperature sensor module of a microwave wireless high temperature sensor based on metamaterials of the present application, Figure 2 is a schematic diagram of a metamaterial array unit of a microwave wireless high temperature sensor based on metamaterials of the present application, Figure 3 is a schematic diagram of a feed network unit of a microwave wireless high temperature sensor based on metamaterials of the present application, Figure 4 is a microwave detection result diagram of a microwave wireless high temperature sensor of a microwave wireless high temperature sensor based on metamaterials under different impedance characteristic loadings of the present application, Figure 5 is a microwave detection result diagram of a microwave wireless high temperature sensor of a microwave wireless high temperature sensor based on metamaterials under different temperature excitations of the present application.

[0022] The application provides a microwave wireless high-temperature sensor based on metamaterials, comprising a temperature sensor module, a rectangular waveguide interrogation antenna module and a vector network analyzer module, the rectangular waveguide interrogation antenna module is an actual transceiver front end of a measurement signal, to radiate and receive microwave signals, the vector network analyzer module is used for analyzing, judging and acquiring important roles of temperature signals in the temperature measurement and monitoring process; the temperature sensor module comprises a metamaterial array unit 101, a feed network unit 102 and a thermistor unit 103, the metamaterial array unit 101 is used for receiving electromagnetic signals emitted by the interrogation antenna, and radiating echo signals from the load back to the interrogation antenna; the feed network unit 102 outputs the electromagnetic signals captured from the metamaterial array unit 101 through a metallized via, and realizes feeding of the thermistor unit 103 through a coaxial output structure. The metamaterial array unit 101 is composed of 8*8 metamaterial units. The feed network unit 102 can also output the electromagnetic signals reflected from the load to the metamaterial array in the reverse direction to feed back measurement information. The thermistor unit 103 is a coaxial structure thermistor load, the thermistor load is connected to the output end of the feed network unit 102, the thermistor load is excited by different ambient temperatures, thereby generating different impedance characteristics, so that the microwave signals from the feed network produce different intensity signal reflections, to characterize the temperature information of the test environment through electromagnetic echo signals. The coaxial structure is a ceramic filling structure.

[0023] In the embodiment, the temperature measuring sensor module adopts integrated design idea, by integrating the metamaterial array unit 101, the feed network unit 102 and the thermal sensitive platinum resistance unit 103, the temperature measuring sensor module is compact, light, wireless feed and has strong adaptability. The rectangular waveguide interrogation antenna module is used as the actual transceiver front end of the measurement signal, mainly realizes the radiation and reception of the microwave signal, and the working frequency is 6.5GHz. The vector network analyzer module is used as the actual analysis processing device, plays an important role in temperature signal analysis, judgment and acquisition in the temperature measurement and monitoring process. The metamaterial array unit 101 is composed of 8*8 metamaterial units (68mm x 68mm), which functions to receive the electromagnetic signal emitted by the interrogation antenna, and radiate the echo signal from the load back to the interrogation antenna. In actual work, the electromagnetic signal capture efficiency and radiation efficiency of the metamaterial array unit 101 are closely related to the real-time impedance characteristics of the thermal sensitive platinum resistance unit 103 at the load end. The feed network unit 102 for microwave signal output is followed by the metamaterial array unit 101, which outputs the electromagnetic signal captured from the metamaterial array unit 101 through the metallized via, and finally realizes the feed of the load thermal sensitive resistance through the coaxial output structure. In addition, the feed network unit 102 also reversely outputs the electromagnetic signal reflected from the load to the metamaterial array unit 101, realizing the measurement information feedback. At the output end of the feed network unit 102, the thermal sensitive load with coaxial structure is followed. It is excited by different environmental temperatures, thereby producing different impedance characteristics, and then making the microwave signal from the feed network unit 102 produce different intensity signal reflections, finally realizing the temperature information of the test environment through the electromagnetic echo signal. In order to make the sensor have higher temperature measurement and monitoring capability, the load coaxial structure is ceramic filling structure, and the category of the load thermal sensitive resistance is Pt100 (TCR=3850ppm / K), and the working range is 0℃-1150℃. In order to realize convenient installation and application, the flange and bolt structure are used for fixing.

[0024] As Figure 4As shown, the microwave test results of the sensor under different characteristic impedance load elements show that, since the output load coaxial structure is designed as a characteristic impedance of 50 ohms, when the load characteristic impedance is 100Ω, the matching characteristic is closest to the impedance matching result, at this time the electromagnetic signal return strength from the sensor received by the interrogation antenna is the minimum value of-27.98dB. With the continuous increase of the load impedance characteristic value, the impedance matching characteristic of the probe is further deteriorated, and the return strength from the sensor gradually increases, at this time the return signal strength received by the interrogation antenna is-23.928dB, -22.12dB, -21.16dB and-20.58dB in turn. As shown in the figure, Figure 5 As shown, the system temperature measurement results show that the electromagnetic return response generated by the temperature sensor under different temperature excitations has good distinguishability and recognizability. In addition, the test results show that the sensor has reliable measurement and monitoring capability within the working temperature range of the thermistor.

[0025] The microwave wireless high-temperature sensor based on metamaterials of the present application is based on the perfect electromagnetic wave absorption characteristics of electromagnetic metamaterials under good impedance matching. Through the design of the super material array unit 101 of the electromagnetic signal receiving array, the feed network unit 102 of the electromagnetic signal output, and the introduction of the thermistor platinum resistance unit 103, in the working process, the wave absorber array first captures the electromagnetic signal emitted by the interrogation antenna, and then the captured electromagnetic signal is output to the load thermistor platinum resistance unit 103 end through the feed network unit 102. At this time, the platinum resistance with different characteristics will produce electromagnetic reflection with different intensities, and finally be fed back to the interrogation antenna by the wave absorber array. Since the thermistor platinum resistance is extremely sensitive to temperature, different degrees of return signal represent different measured temperatures, so the return signal of the wave absorber array obtained by the interrogation antenna can obtain the temperature information of the test environment / device, and finally complete the wireless temperature measurement. In addition, since the test probe end (platinum resistance) is a coaxial structure, the size and volume of the structure can be customized, and the feature is small, so it can be embedded for integrated design, thereby realizing temperature monitoring and measurement of the internal environment of a sealed cavity. It can be seen that the proposed microwave temperature sensor not only has wireless temperature measurement capability, but also has temperature measurement and monitoring capability for closed high-temperature and high-pressure devices / environment. In addition, the integrated design gives the sensor more compact and portable characteristics.

[0026] The above only discloses one or more preferred embodiments of the present application, and cannot limit the scope of the rights of the present application. Those skilled in the art can understand that all or part of the above-mentioned embodiments can be implemented, and equivalent changes made according to the claims of the present application still belong to the scope covered by the present application.

Claims

1.A metamaterial-based microwave wireless high-temperature sensor, characterized in that, it comprises a temperature sensor module, a rectangular waveguide interrogation antenna module and a vector network analyzer module, the rectangular waveguide interrogation antenna module is an actual transceiver front end of a measurement signal, to radiate and receive a microwave signal, the vector network analyzer module is used for analyzing, judging and acquiring a temperature signal in a temperature measurement and monitoring process; the temperature sensor module comprises a metamaterial array unit, a feed network unit and a thermistor unit, the metamaterial array unit is used for receiving an electromagnetic signal emitted by an interrogation antenna, and radiating a return signal from a load back to the interrogation antenna; the feed network unit outputs energy of the electromagnetic signal captured from the metamaterial array unit through a metallized via, and feeds the thermistor unit through a coaxial output structure; the metamaterial array unit is composed of a 8*8 metamaterial unit; the feed network unit can also output the electromagnetic signal reflected from the load to the metamaterial array in a reverse direction, to feed back measurement information; the thermistor unit is a coaxial structure thermistor load, which is connected to an output end of the feed network unit, and the thermistor load is excited by different ambient temperatures to generate different impedance characteristics, so that the microwave signal from the feed network generates different intensity signal reflections, to characterize the temperature information of a test environment through electromagnetic return signals. 2.The metamaterial-based microwave wireless high-temperature sensor according to claim 1, characterized in that, the coaxial structure is a ceramic-filled structure.

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