A combined patch antenna sensor and sensing system

Abstract

The application relates to a combined patch antenna sensor and a sensing system, the sensor comprising component one, component two and component three, component one comprising a substrate, a receiving broadband antenna, a transmitting broadband antenna, a microstrip line, a spiral resonator left radiation patch, a microstrip feed line and an RFID chip, component two comprising a mobile substrate and a spiral resonator right radiation patch below the mobile substrate, and component three comprising a connecting line and a connecting plate, the polarization directions of the receiving broadband antenna and the transmitting broadband antenna being crossed. Compared with the prior art, the polarization directions of the receiving broadband antenna and the transmitting broadband antenna in the sensor are crossed, so that the interference of environmental reflection on the backscattering signal of the antenna sensor is effectively avoided.

Description

Technical Field

[0001] This invention relates to the field of antenna sensors, and in particular to a combined patch antenna sensor and sensing system. Background Technology

[0002] During long-term use, civil engineering structures often undergo degradation due to external environmental factors and loads, resulting in stress deformation and cracking. This poses potential risks to the safe and reliable operation of the structure, and in severe cases, can even lead to structural damage and failure. Therefore, throughout the entire life cycle of a structure, it is necessary to monitor relevant physical quantities (displacement, strain, acceleration, etc.) to understand its service status in a timely manner and ensure its safe and reliable use.

[0003] Currently, sensing technologies and sensors used for structural health monitoring are developing rapidly, including various types of sensors based on piezoresistive impedance, acoustic emission, and fiber optic sensing technologies. These sensors typically offer advantages such as high resolution and good stability; however, most still require a continuous power supply and wired signal transmission, leading to complex wiring, time-consuming and labor-intensive installation, high costs, and difficulty in maintenance. Furthermore, current sensors based on patch antennas often face self-interference issues in wireless reading, where the intensity of reflected environmental signals is much greater than the intensity of the antenna's backscattered signal, severely impacting the sensor's wireless reading distance and measurement accuracy. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art by providing a combined patch antenna sensor and sensing system. By crossing the polarization directions of the receiving broadband antenna and the transmitting broadband antenna in the sensor, the interference of environmental reflection on the backscattered signal of the antenna sensor is effectively avoided, and it can work passively and wirelessly, reducing installation costs.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A combined patch antenna sensor includes three components: component one, component two, and component three. Component one includes a receiving broadband antenna and a transmitting broadband antenna connected by a microstrip line. A left-radiating patch of a spiral resonator is provided inside the microstrip line. Component one also includes a substrate and a radio frequency identification (RFID) chip. The receiving broadband antenna, the transmitting broadband antenna, the microstrip line, and the left-radiating patch of the spiral resonator are disposed on the upper surface of the substrate. The RFID chip is connected to the microstrip line through a microstrip feed line. The polarization directions of the receiving broadband antenna and the transmitting broadband antenna intersect.

[0007] Component 2 includes a right-radiating patch of a spiral resonator on the lower surface of the substrate and a movable substrate. The right-radiating patch of the spiral resonator and the left-radiating patch of the spiral resonator are tightly bonded together to form a combined spiral resonator. The combined spiral resonator is coupled to a microstrip line. The right-radiating patch of the spiral resonator and the left-radiating patch of the spiral resonator can be staggered relative to each other. The resonant ring widths of the right-radiating patch of the spiral resonator and the left-radiating patch of the spiral resonator are equal.

[0008] Component 3 includes connecting wires and connecting plates. The movable substrate is connected to the connecting plate via connecting wires on the side away from the substrate.

[0009] Furthermore, the receiving broadband antenna, transmitting broadband antenna, microstrip line, left radiating patch of spiral resonator, microstrip feed line, and right radiating patch of spiral resonator are all made of copper.

[0010] Furthermore, both the substrate and the movable substrate use RT5880 dielectric boards, and the connecting lines and connecting plates are made of rigid materials with a dielectric constant close to 1.

[0011] Furthermore, the movable substrate and the connecting line are rigidly connected, and the connecting line and the connecting plate are rigidly connected.

[0012] In another aspect of the present invention, a combined patch antenna sensing system is proposed, which employs the above-mentioned combined patch antenna sensor. The sensing system further includes a reader, which is wirelessly connected to a radio frequency identification chip. The reader is used to receive the echo signal transmitted by the transmitting broadband antenna.

[0013] Furthermore, the reader includes a wireless transceiver module, a control module, a modem module, and a digital processing module.

[0014] Furthermore, the control module is used to control the reader of the sensing system and to transmit modulated electromagnetic wave signals of different frequencies to the sensor.

[0015] Furthermore, the digital processing module obtains the resonant frequency of the combined helical resonator by finding the phase fluctuations and amplitude attenuation of the echo signal.

[0016] Furthermore, the reader is used to receive electromagnetic wave signals carrying tag numbers and location information transmitted by the transmitting broadband antenna.

[0017] Furthermore, the reader is used to send interrogation signals to the receiving broadband antenna.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] (1) The present invention crosses the polarization directions of the receiving broadband antenna and the transmitting broadband antenna in the sensor, and crosses the polarization of the environmental reflection signal and the sensor backscatter signal in the echo signal. The reader can use a receiving antenna with a specific polarization direction to receive only the sensor backscatter signal, which effectively avoids the interference of environmental reflection on the antenna sensor backscatter signal and improves the wireless reading distance and accuracy of the sensing system.

[0020] (2) This invention is a passive wireless sensing system. Passive means that this invention does not require pre-installed batteries or wires for energy input, but instead receives electromagnetic waves from the transmitting antenna for energy input. Wireless means that this invention does not require additional lines for data transmission. Specifically, when the structure deforms, the overall length of the spiral resonator in the sensor changes, thereby changing its resonant frequency. The change in resonant frequency can be passively and wirelessly obtained through a reader, which greatly reduces the labor required for sensor installation and the cost of the sensing system.

[0021] (3) The present invention collects echo signals and uses the amplitude attenuation and phase fluctuation in the echo signals as sensing parameters, which avoids the problem that the measurement of a single sensing parameter in wireless measurement is easily affected by the environment and improves the accuracy of wireless measurement. Attached Figure Description

[0022] Figure 1 This is a structural diagram of the present invention;

[0023] Figure 2 This is a schematic diagram of the structure of component one of the present invention;

[0024] Figure 3 This is a schematic diagram of component two of the present invention;

[0025] Figure 4 This is a schematic diagram of the structure of component three of the present invention;

[0026] Figure 5 This is a schematic diagram of the sensing system of the present invention;

[0027] In the figure, substrate 1, receiving broadband antenna 2, transmitting broadband antenna 3, microstrip line 4, left radiating patch of spiral resonator 5, microstrip feed line 6, RFID chip 7, moving substrate 8, right radiating patch of spiral resonator 9, connecting line 10, connecting board 11, reader 12. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0030] Example 1:

[0031] This invention proposes a combined patch antenna sensor and sensing system. The polarization crossover of the transmit and receive signals can avoid interference from environmental reflected signals and improve the wireless reading distance. At the same time, the reader can wirelessly query the multi-dimensional electromagnetic characteristic parameters of the sensor, which can improve the accuracy of wireless measurement.

[0032] This invention proposes a combined patch antenna sensor, the structure of which is as follows: Figure 1 As shown in the diagram. The sensor includes component one, component two, and component three. Component one includes a substrate 1, a receiving broadband antenna 2, a transmitting broadband antenna 3, a microstrip line 4, a left radiating patch of a spiral resonator 5, a microstrip feed line 6, and an RFID chip 7. Component two includes a movable substrate 8 and a right radiating patch of a spiral resonator 9 below the movable substrate 8. Component three includes a connecting line 10 and a connecting plate 11. The structural diagram of component one is shown below. Figure 2 As shown, the structural diagram of component two is as follows: Figure 3 As shown, the structural diagram of component three is as follows: Figure 4 As shown.

[0033] The receiving broadband antenna 2, the transmitting broadband antenna 3, the microstrip line 4, and the left radiating patch 5 of the helical resonator are tightly electroplated and bonded to the upper surface of the substrate 1. The RFID chip 7 is soldered to the upper surface of the substrate 1 and connected to the microstrip line 4 through the microstrip feed line 6.

[0034] The right-radiating patch 9 of the spiral resonator below the moving substrate 8 is tightly electroplated and bonded to the lower surface of the moving substrate 8. Component 2 is placed on component 1, so that the right-radiating patch 9 of the spiral resonator below the moving substrate and the left-radiating patch 5 of the spiral resonator on component 1 are tightly bonded, with the upper and lower parts overlapping to form a short circuit, forming a combined spiral resonator. The right-radiating patch 9 and the left-radiating patch 5 of the spiral resonator below the moving substrate can be offset from each other. Furthermore, the resonant ring widths of the right-radiating patch 9 and the left-radiating patch 5 of the spiral resonator below the moving substrate are equal. The combined spiral resonator is coupled to the microstrip line 4, which can be equivalent to a bandpass filter. When current flows through the microstrip line, it introduces amplitude attenuation and phase fluctuations to signals with the same resonant frequency as the spiral resonator.

[0035] In some embodiments, the movable substrate 8 is rigidly connected to the connecting line 10, and the connecting line 10 is rigidly connected to the connecting plate 11. The receiving broadband antenna 2, the transmitting broadband antenna 3, the microstrip line 4, the left radiating patch of the spiral resonator 5, the microstrip feed line 6, and the right radiating patch of the spiral resonator 9 are all made of copper. The substrate 1 and the movable substrate 8 are both made of RT5880 dielectric substrate. The connecting line 10 and the connecting plate 11 are both made of rigid materials with a dielectric constant close to 1 to reduce the impact on the electromagnetic field of the antenna jointly formed by component one and component two.

[0036] The movable substrate 8 is connected to the connecting plate 11 via a connecting line 10 on the side away from the substrate 1. Component 1 and the connecting plate 11 are adhered to the structural surface. When the structural surface deforms, relative displacement occurs between component 1 and components 2 and 3, causing the right radiating patch 9 and the left radiating patch 5 of the spiral resonator below the movable substrate to shift relative to each other. This results in a change in the overall length of the spiral resonator, thus altering its resonant frequency. In other words, the resonant frequency of the spiral resonator is related to the overlap length between the two radiating patches; an increase in overlap length leads to an increase in resonant frequency, while a decrease in overlap length leads to a decrease in resonant frequency.

[0037] In this invention, the polarization directions of the receiving broadband antenna 2 and the transmitting broadband antenna 3 intersect. That is, the interrogation electromagnetic wave received by the sensor and the electromagnetic wave emitted by the sensor have intersecting polarizations, while the electromagnetic wave reflected from the environment has the same polarization direction as the interrogation electromagnetic wave received by the sensor. Therefore, the environmental reflection signal and the sensor backscattered signal in the echo signal have intersecting polarizations. At the reading end, a receiving antenna with a specific polarization direction can be used to receive only the sensor backscattered signal, thereby avoiding interference from the environmental reflection signal and increasing the wireless reading distance.

[0038] This invention also proposes a combined patch antenna sensing system, including the aforementioned sensor and reader 12. The reader 12 includes a wireless transceiver module, a control module, a modulation / demodulation module, and a digital processing module. The wireless transceiver module and modulation / demodulation module are both known technologies in the art, and existing modulation / demodulation modules and digital processing modules can be used. The structural diagram of the sensing system is shown below. Figure 5 As shown.

[0039] The control module controls the reader 12 of the monitoring sensor system and transmits modulated electromagnetic wave signals of different frequencies to the sensor. The sensor is connected to the RFID chip 7 via a microstrip feed line 6. When the signal power received by the sensor reaches a threshold, the RFID chip 7 is activated.

[0040] The RFID chip 7 is connected to the microstrip line 4 via the microstrip feed line 6. When the RFID chip 7 in the sensor is activated, the transmitting broadband antenna 3 in the sensor emits an electromagnetic wave signal carrying the tag number and location information. This signal is received and processed by the reader 12 to obtain the sensor's location information, etc. When the receiving broadband antenna 2 of the sensor receives an interrogation signal from the reader 12, the receiving broadband antenna 2 generates a surface current, which flows through the microstrip line 4 to the transmitting broadband antenna 3. The transmitting broadband antenna 3 then sends an echo signal back to the reader 12.

[0041] When the frequency of the signal passing through microstrip line 4 matches the resonant frequency of the helical resonator, the helical resonator resonates and generates a surface current, thereby filtering out signals of that frequency and causing amplitude attenuation and phase fluctuations. The digital processing module can obtain the resonant frequency of the helical resonator by detecting the phase fluctuations and amplitude attenuation of the echo signal. When the structural surface deforms, the overall length of the helical resonator in the combined patch antenna sensor changes, causing its resonant frequency to shift. This sensing system can determine the amount of resonant frequency shift, thereby deriving the structural surface deformation and enabling wireless monitoring of structural deformation.

[0042] This invention utilizes the resonant characteristics of a combined patch antenna. The left and right radiating patches of the helical resonator in the sensor constitute a resonant system. When relative movement occurs between the components, the overall length of the helical resonator changes, thereby causing a change in its resonant frequency.

[0043] The sensor of this invention employs a wireless feeding method. The sensor's receiving broadband antenna receives the interrogation signal from the reader. The broadband antenna resonates and generates a surface current, which then flows through the microstrip line to the transmitting broadband antenna. Finally, the transmitting broadband antenna resonates and backscatters the signal. The polarization directions of the receiving and transmitting broadband antennas in the sensor intersect, effectively avoiding interference from environmental reflections on the backscattered signal of the antenna sensor, thus improving the wireless reading distance and accuracy of the sensing system. This invention establishes a relationship between the structural deformation state and the sensor's resonant frequency, causing amplitude attenuation and phase fluctuations in the echo signal. By monitoring the multi-dimensional electromagnetic characteristic parameters of the echo signal, the reader improves the accuracy of its wireless interrogation.

[0044] This invention transmits information via electromagnetic waves, eliminating the need for cables and simplifying the sensing system. This allows for more flexible deployment and reduces the likelihood of failure during natural disasters. Powered by electromagnetic waves, the system eliminates the need for power cords or batteries, significantly reducing labor costs for sensor installation and overall system cost. Based on a stress-free, modular patch antenna, this invention avoids the effects of shear hysteresis and strain transfer efficiency during structural deformation monitoring, resulting in higher measurement accuracy. The RFID chip in this invention stores sensor ID and location information, which can be captured by a reader for rapid sensor localization.

[0045] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A combined patch antenna sensor, characterized by The sensor includes component one, component two and component three. Component one includes a receiving broadband antenna (2) and a transmitting broadband antenna (3) connected by a microstrip line (4). A spiral resonator left radiating patch (5) is provided inside the microstrip line (4). Component one also includes a substrate (1) and a radio frequency identification chip (7). The receiving broadband antenna (2), the transmitting broadband antenna (3), the microstrip line (4) and the spiral resonator left radiating patch (5) are disposed on the upper surface of the substrate (1). The radio frequency identification chip (7) is connected to the microstrip line (4) through a microstrip feed line (6). The polarization directions of the receiving broadband antenna (2) and the transmitting broadband antenna (3) intersect. Component 2 includes a right-radiating patch (9) of a spiral resonator on the lower surface of a substrate (1) and a movable substrate (8). Component 2 is disposed on component 1. The right-radiating patch (9) of the spiral resonator and the left-radiating patch (5) of the spiral resonator are tightly bonded together, and the upper and lower parts overlap to form a short circuit, forming a combined spiral resonator. The combined spiral resonator is coupled on a microstrip line (4). The right-radiating patch (9) of the spiral resonator and the left-radiating patch (5) of the spiral resonator can move relative to each other, thereby causing the overall length of the spiral resonator to change. The resonant ring widths of the right-radiating patch (9) of the spiral resonator and the left-radiating patch (5) of the spiral resonator are equal. Component 3 includes a connecting line (10) and a connecting plate (11). The movable substrate (8) is connected to the connecting plate (11) via the connecting line (10) on the side away from the substrate (1).

2. The combination patch antenna sensor of claim 1, wherein, The receiving broadband antenna (2), transmitting broadband antenna (3), microstrip line (4), left radiating patch of spiral resonator (5), microstrip feed line (6), and right radiating patch of spiral resonator (9) are all made of copper.

3. The combination patch antenna sensor of claim 1, wherein, The substrate (1) and the movable substrate (8) are both made of RT5880 dielectric board, and the connecting line (10) and the connecting plate (11) are both made of rigid material.

4. The combination patch antenna sensor of claim 1, wherein, The movable substrate (8) and the connecting line (10) are rigidly connected, and the connecting line (10) and the connecting plate (11) are rigidly connected.

5. A combined patch antenna sensor system, characterized by The combined patch antenna sensor according to any one of claims 1 to 4 is used. The sensing system further includes a reader (12), which is wirelessly connected to the radio frequency identification chip (7). The reader (12) is used to receive the echo signal transmitted by the transmitting broadband antenna (3).

6. The combined patch antenna sensor system of claim 5, wherein, The reader (12) includes a wireless transceiver module, a control module, a modulation and demodulation module, and a digital processing module.

7. The combined patch antenna sensor system of claim 6, wherein, The control module is used to control the reader (12) of the sensing system and to transmit modulated electromagnetic wave signals of different frequencies to the sensor.

8. The combined patch antenna sensor system of claim 6, wherein, The digital processing module obtains the resonant frequency of the combined spiral resonator by finding the phase fluctuations and amplitude attenuation of the echo signal.

9. The combined patch antenna sensor system of claim 5, wherein, The reader (12) is used to receive electromagnetic wave signals with tag number and location information transmitted by the transmitting broadband antenna (3).

10. The combined patch antenna sensor system of claim 5, wherein, The reader (12) is used to send an interrogation signal to the receiving broadband antenna (2).

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