Antenna sensor and antenna sensing system based on L-shaped resonator

Abstract

The invention relates to an antenna sensor and an antenna sensing system based on L-shaped resonators, the antenna sensor comprises a first assembly, a second assembly and a third assembly, the detection surface of the first assembly is in contact with the detection surface of the second assembly, the detection surface of the first assembly is an L-shaped resonator array, and the detection surface of the third assembly is an L-shaped resonator array. The detection surface of the second assembly is a short-circuit sub-patch array corresponding to the L-shaped resonator array, the supporting surface of the first assembly is connected with one end of a to-be-detected structure, and the supporting surface of the second assembly is connected to the other end of the to-be-detected structure through the third assembly. Compared with the prior art, the system has the advantages of small self-interference degree, long wireless reading distance, high measurement precision and the like.

Description

Technical Field

[0001] The present invention relates to the field of antenna sensors, and in particular to an antenna sensor and an antenna sensing system based on an L-shaped resonator. Background Art

[0002] During long-term use, civil engineering structures often degrade due to the influence of external environment and load factors, resulting in stress deformation and cracking, which poses a hidden danger to the safe and reliable operation of the structure, and even causes structural damage and failure in serious cases. Therefore, during the entire life cycle of the structure, it is necessary to monitor the physical quantities related to the structural state (displacement, strain, acceleration, etc.) in order to timely understand the service status of the structure and ensure the safe and reliable use of the structure.

[0003] At present, sensing technologies and sensors used for structural health monitoring are developing rapidly, such as different forms of sensors based on piezoelectric impedance, acoustic emission, optical fiber and other sensing technologies. These sensors usually have the advantages of high resolution and good stability, but most of them still require continuous power supply and use wired methods to transmit collected signals, which will lead to complex wiring of the monitoring system, time-consuming and labor-intensive installation, high cost and difficult maintenance. Current passive wireless sensors based on patch antennas often face self-interference in wireless reading, that is, the reflected signal strength of the structure where the sensor is deployed is much greater than the antenna backscattered signal strength, which seriously affects the wireless reading distance and measurement accuracy of the sensor.

[0004] Therefore, it is necessary to develop a sensor with low self-interference, long wireless reading distance and high measurement accuracy for structural monitoring. Summary of the invention

[0005] The purpose of the present invention is to provide an antenna sensor and an antenna sensing system based on an L-shaped resonator in order to overcome the defects of the above-mentioned prior art, such as strong self-interference, short reading distance and low accuracy.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] An antenna sensor based on an L-shaped resonator comprises a first component, a second component and a third component. The detection surface of the first component is arranged in contact with the detection surface of the second component. The detection surface of the first component is an L-shaped resonator array, and the detection surface of the second component is a short-circuit sub-patch array corresponding to the L-shaped resonator array. The supporting surface of the first component is connected to one end of a structure to be measured, and the supporting surface of the second component is connected to the other end of the structure to be measured through the third component.

[0008] Furthermore, the first component includes a first dielectric substrate, an L-shaped resonator array and a ground plane. The L-shaped resonator array is arranged on one side of the dielectric substrate, and the other side is connected to the ground plane. The ground plane is structurally connected to one side of the gap to be measured.

[0009] Furthermore, the second component includes a second dielectric substrate and a shorting sub-patch array. The shorting sub-patch array is arranged on one side of the second dielectric substrate, and the other side is connected to the third component.

[0010] Furthermore, the third component is a rigid connection member, and the third component is rigidly connected to the supporting surface of the second component.

[0011] Furthermore, the first component includes a first dielectric substrate, the second component includes a second dielectric substrate, and the first dielectric substrate and the second dielectric substrate are RT5880 dielectric substrates.

[0012] Furthermore, the L-shaped resonator array and the short-circuit patch array are both made of copper.

[0013] In a second aspect of the present invention, an antenna sensing system based on an L-shaped resonator includes any of the above antenna sensors based on an L-shaped resonator, and also includes a reader, wherein the reader transmits a polarized inquiry signal in the horizontal / vertical direction to the antenna sensor, and the antenna sensor simultaneously scatters backscattered signals in the horizontal and vertical directions to the reader, and the reader only receives backscattered signals in the vertical / horizontal direction.

[0014] Furthermore, the reader includes a wireless transceiver module, a control module, a modulation and demodulation module and a digital processing module. The control module is connected to the wireless transceiver module to control the generation of polarized inquiry signals. The modulation and demodulation module is connected to the wireless transceiver module to demodulate the backscattered signal to obtain the resonant frequency of the antenna sensor. The digital processing module is connected to the modulation and demodulation module to calculate the crack width information based on the resonant frequency of the antenna sensor.

[0015] Furthermore, the digital processing module obtains the resonant frequency of the antenna sensor by finding the signal frequency corresponding to the highest amplitude point of the backscattered signal.

[0016] Furthermore, the control module is used to control the reader and transmit polarized inquiry signals of multiple frequencies to the antenna sensor.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1) When the structure to be measured produces a fracture separation displacement, the present invention produces a relative displacement between the two detection surfaces, so that the effective length of the L-shaped resonator changes and the resonant frequency changes, so that the fracture separation displacement of the structure to be measured is obtained through its resonant frequency, thereby realizing the measurement of cracks with high measurement accuracy.

[0019] 2) The present invention realizes the simultaneous outward backscattering of horizontally polarized and vertically polarized signals through the depolarization mechanism of the L-shaped resonator. The reader uses cross-polarization to read the backscattered signals, thereby avoiding the interference of structural reflection on the backscattered signals of the antenna sensor, reducing the influence of self-interference, and increasing the maximum inquiry distance of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural diagram of the present invention;

[0021] Figure 2 is a schematic structural diagram of a first component of the present invention;

[0022] Figure 3 is a schematic structural diagram of the second component of the present invention;

[0023] Figure 4 is a schematic structural diagram of the third component of the present invention;

[0024] Figure 5 It is a structural schematic diagram of the sensing system of the present invention;

[0025] Explanation of the markings in the figure: 1. first dielectric substrate, 2. L-shaped resonator array, 3. ground plane, 4. second dielectric substrate, 5. short-circuit patch array, 6. rigid connection component, 7. structure to be measured, 8. reader. DETAILED DESCRIPTION

[0026] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0027] Example 1

[0028] The present invention is an antenna sensor based on an L-shaped resonator, which utilizes a depolarization mechanism to simultaneously backscatter horizontally polarized and vertically polarized signals, thereby avoiding interference of structural reflection on the backscattered signals of the antenna sensor and significantly improving the maximum distance of wireless inquiry of the antenna sensor.

[0029] like Figure 1 As shown, it includes a first component, a second component and a third component. The detection surface of the first component and the detection surface of the second component are arranged in contact with each other. The detection surface of the first component is an L-shaped resonator array 2, and the detection surface of the second component is a short-circuit sub-patch array 5 corresponding to the L-shaped resonator array 2. The supporting surface of the first component is connected to one end of the structure to be measured 7, and the supporting surface of the second component is connected to the other end of the structure to be measured 7 through the third component.

[0030] like Figure 2 As shown, the first component includes a first dielectric substrate 1, an L-shaped resonator array 2 and a ground plane 3. The L-shaped resonator array 2 is arranged on one side of the dielectric substrate 1, and the other side is connected to the ground plane 3. The ground plane 3 is connected to a side structure of the gap to be measured.

[0031] like Figure 3 As shown, the second component includes a second dielectric substrate 4 and a shorting sub-patch array 5. The shorting sub-patch array 5 is arranged on one side of the second dielectric substrate 4, and the other side is connected to the third component.

[0032] like Figure 4 As shown, the third component is a rigid connection member 6, and the third component is rigidly connected to the supporting surface of the second component.

[0033] The shorting sub-patch array 5 is closely attached to the L-shaped resonator array 2, and the upper and lower parts overlap to form a short circuit, forming a combined L-shaped resonator array, and the shorting sub-patch array 5 below the second dielectric substrate 4 and the L-shaped resonator array 2 above the first dielectric substrate 1 can be shifted relative to each other. In addition, the width of the shorting sub-patch array 5 below the second dielectric substrate 4 is equal to that of the L-shaped resonator array 2 above the first dielectric substrate 1.

[0034] In some embodiments, the rigid connection member 6 and the upper surface of the dielectric substrate 4 are rigidly connected, and the two keep moving synchronously. The L-shaped resonator array 2 and the short-circuit patch array 5 are made of copper, and the dielectric substrate 1 and the dielectric substrate 4 are both made of RT5880 dielectric substrates. This dielectric substrate has low loss and can prevent scattered signals from being absorbed by the dielectric substrate. The rigid connection member 6 is made of a rigid material with a dielectric constant close to 1 to reduce the impact on the electromagnetic field of the antenna formed by the first component and the second component.

[0035] When the antenna sensor receives a horizontally (vertically) polarized interrogation signal, the L-shaped resonator array absorbs the signal at its resonant frequency and produces electromagnetic resonance, and then backscatters horizontally polarized and vertically polarized signals outward at the same time. The gap width can be obtained by receiving and solving the backscattered signal.

[0036] The second dielectric substrate 4 is connected to the structural surface 7 by a rigid connection member 6 on the side of the crack away from the first dielectric substrate 1. The first component and the rigid connection member 6 are attached to the structural surface. When the crack on the structural surface expands, relative displacement occurs between the first component and the second component and the third component, so that the short-circuit patch array 5 below the second dielectric substrate 4 and the L-shaped resonator array 2 above the first dielectric substrate 1 are mutually displaced, thereby causing the overall length of the combined L-shaped resonator array to change, thereby changing its resonant frequency. In other words, the resonant frequency of the combined L-shaped resonator array is related to the overlap length between the first component and the second component. When the overlap length increases, the resonant frequency increases; when the overlap length decreases, the resonant frequency decreases.

[0037] Example 2

[0038] On the basis of Example 1, the present invention further proposes an antenna sensing system based on an L-shaped resonator, including the sensor and reader 8 proposed in Example 1. The reader 8 includes a wireless transceiver module, a control module, a modulation and demodulation module and a digital processing module. The control module is connected to the wireless transceiver module to control the generation of the polarized inquiry signal. The modulation and demodulation module is connected to the wireless transceiver module to demodulate the backscattered signal to obtain the resonant frequency of the antenna sensor. The digital processing module is connected to the modulation and demodulation module to calculate the crack width information based on the resonant frequency of the antenna sensor. The wireless transceiver module and the modulation and demodulation module are both commonly known technologies in the field, and the existing modulation and demodulation modules and digital processing modules can be used. The structural diagram of the antenna sensing system is shown in FIG. Figure 5 shown.

[0039] The control module is used to control the reader 8 of the monitoring sensor system and transmit modulated electromagnetic wave signals of different frequencies to the sensor. When the signal received by the sensor matches the resonant frequency of the combined L-shaped resonator array, the combined L-shaped resonator array absorbs the energy of the corresponding electromagnetic wave and resonates electromagnetically, and then backscatters horizontally polarized and vertically polarized signals outward at the same time. The modulation and demodulation module of the reader can extract the resonant frequency of the sensor from the received signal, further calculate the crack width, and realize wireless monitoring of the expansion of structural cracks.

[0040] When the antenna sensor receives a horizontally (vertically) polarized interrogation signal, i.e., a modulated electromagnetic wave signal, the L-shaped resonator array absorbs the signal at its resonant frequency and generates electromagnetic resonance, and then backscatters horizontally polarized and vertically polarized signals outward at the same time, while the reader 8 receiving antenna is set to receive only vertically (horizontally) polarized signals, i.e., the reader 8 can only receive the vertically (horizontally) polarized backscattered signal of the sensor, which can avoid the signal reflected by the structure 7 to interfere with the scattered signal of the sensor, and the frequency corresponding to the peak of the signal intensity is the resonant frequency of the L-shaped resonator array. Therefore, the polarization direction of the received signal of the reader 8 needs to be orthogonal to the polarization direction of its transmitted signal to ensure the signal quality of the signal transmission process.

[0041] In the present invention, the resonant characteristics of the combined L-shaped resonator are applied. The short-circuit patch array and the L-shaped resonator array in the sensor together constitute a resonant system. When relative movement occurs between the components, the overall length of the combined L-shaped resonator changes, thereby causing a change in its resonant frequency. And due to the asymmetry of the planar structure, the combined L-shaped resonator can simultaneously generate horizontally polarized and vertically polarized signals.

[0042] The antenna sensor of the present invention adopts a wireless feeding method. The antenna sensor can receive the inquiry signal from the reader, and the combined L-shaped resonator array absorbs the energy of the corresponding electromagnetic wave and generates electromagnetic resonance, and then backscatters horizontally polarized and vertically polarized signals outward at the same time. The cross-polarization reading technology is used at the reading end to avoid the interference of the structure reflection signal on the backscattered signal of the antenna sensor, thereby improving the wireless reading distance of the sensing system.

[0043] The present invention transmits information through electromagnetic waves, without the need for cables, making the sensor system simpler, more flexible in layout, and less likely to fail in natural disasters. By providing energy through electromagnetic waves, there is no need for power cords or batteries to provide energy for the sensor system, which greatly reduces the labor required to install the antenna sensor and the cost of the sensor system. The present invention is based on a stress-free combined patch antenna, which can avoid the influence of shear lag and strain transfer efficiency during structural deformation monitoring, making the measurement results more accurate.

[0044] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. An antenna sensor based on an L-shaped resonator, characterized in that: The invention comprises a first component, a second component and a third component, wherein a detection surface of the first component and a detection surface of the second component are arranged in contact with each other, the detection surface of the first component is an L-shaped resonator array (2), the detection surface of the second component is a short-circuit sub-patch array (5) corresponding to the L-shaped resonator array (2), the support surface of the first component is connected to one end of a structure to be measured (7), and the support surface of the second component is connected to the other end of the structure to be measured (7) through the third component.

2. The antenna sensor based on an L-shaped resonator according to claim 1, characterized in that: The first component comprises a first dielectric substrate (1), an L-shaped resonator array (2) and a ground plane (3); the L-shaped resonator array (2) is arranged on one side of the dielectric substrate (1), and the other side is connected to the ground plane (3); the ground plane (3) is structurally connected to one side of the gap to be measured.

3. The antenna sensor based on an L-shaped resonator according to claim 1, characterized in that: The second component comprises a second dielectric substrate (4) and a shorting sub-patch array (5); the shorting sub-patch array (5) is arranged on one side of the second dielectric substrate (4), and the other side is connected to the third component.

4. The antenna sensor based on an L-shaped resonator according to claim 1, characterized in that: The third component is a rigid connection member (6), and the third component is rigidly connected to the support surface of the second component.

5. The antenna sensor based on an L-shaped resonator according to claim 1, characterized in that: The first component comprises a first dielectric substrate (1), and the second component comprises a second dielectric substrate (4). The first dielectric substrate (1) and the second dielectric substrate (4) are RT5880 dielectric substrates.

6. The antenna sensor based on an L-shaped resonator according to claim 1, characterized in that: The L-shaped resonator array (2) and the short-circuit patch array (5) are both made of copper.

7. An antenna sensing system based on an L-shaped resonator, characterized in that: It comprises an antenna sensor based on an L-shaped resonator as described in any one of claims 1 to 6, and also comprises a reader (8), wherein the reader (8) transmits a polarized inquiry signal in a horizontal / vertical direction to the antenna sensor, the antenna sensor scatters backscattered signals in both horizontal and vertical directions to the reader (8), and the reader (8) only receives backscattered signals in the vertical / horizontal direction.

8. The antenna sensing system based on an L-shaped resonator according to claim 7, characterized in that: The reader (8) comprises a wireless transceiver module, a control module, a modulation and demodulation module and a digital processing module, wherein the control module is connected to the wireless transceiver module to control the generation of a polarized interrogation signal, and the modulation and demodulation module is connected to the wireless transceiver module to demodulate the backscattered signal to obtain the resonant frequency of the antenna sensor; The digital processing module is connected to the modulation and demodulation module, and obtains crack width information based on the resonance frequency of the antenna sensor.

9. The antenna sensing system based on an L-shaped resonator according to claim 8, characterized in that: The digital processing module obtains the resonance frequency of the antenna sensor by finding the signal frequency corresponding to the highest amplitude point of the backscattered signal.

10. The antenna sensing system based on an L-shaped resonator according to claim 8, characterized in that: The control module is used to control the reader (8) and transmit polarized inquiry signals of multiple frequencies to the antenna sensor.

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