Piezoelectric unit and patterned circuit combined ultrasonic-ultrahigh frequency integrated sensor

Abstract

The invention relates to a piezoelectric unit and patterned circuit combined ultrasonic-ultrahigh frequency integrated sensor. The integrated sensor comprises an ultrasonic unit, an ultrahigh frequency unit and a signal acquisition circuit, wherein the ultrasonic unit and the ultrahigh frequency unit are arranged in a multi-band resonant cavity of a cavity; the signal acquisition circuit is in signal connection with the ultrasonic unit and the ultrahigh frequency unit; the ultrasonic unit and the ultrahigh frequency unit are integrated on the same substrate by adopting an orthogonal different-plane stacking structure; the ultrasonic unit comprises a piezoelectric plate arranged on the substrate and a gradient sound matching layer arranged on the side, away from the substrate, of the piezoelectric plate. And the ultrahigh frequency unit comprises a piezoelectric substrate arranged on the substrate and a patterned circuit which is etched on the surface of one side, far away from the substrate, of the piezoelectric substrate and has a defected ground structure. Compared with the prior art, the ultrasonic sensing unit and the ultrahigh frequency sensing unit are organically combined, so that the synchronism and the accuracy of signal monitoring are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power equipment condition monitoring and fault diagnosis, and particularly to an ultrasonic-UHF integrated sensor combining a piezoelectric unit and a patterned circuit. Background Art

[0002] Partial discharge is one of the important reasons leading to the insulation deterioration of power equipment and causing faults. Ultrasonic waves and electromagnetic pulses, as two key characteristic signals reflecting the latent discharge defects of power equipment, accurate monitoring of them is of great significance for ensuring the safe operation of power equipment. However, affected by the impedance mismatch of "gas / oil insulation medium - metal shell - atmosphere", the ultrasonic wave energy attenuates severely during propagation. How to effectively integrate the ultrasonic sensing function and improve the sensing sensitivity has always been a difficult problem in the industry. Traditional monitoring methods often use multiple independent sensors to detect ultrasonic and electromagnetic signals respectively, which have technical problems such as complex equipment, high cost, and poor signal synchronization.

[0003] In existing partial discharge detection sensor solutions that integrate ultrasonic and UHF, such as the GIS partial discharge external ultrasonic and UHF integrated sensor disclosed in Chinese Patent Application CN202210392510.2, which uses PVDF material, there are problems such as easy detachment of electrode welding and insufficient anti-interference ability, which affect the signal detection sensitivity and accuracy, and the installation is restricted by the size and structure of GIS equipment, with a narrow application range. For example, the integrated sensor for partial discharge detection of various power equipment disclosed in Chinese Patent Application CN202211187876.2 has an acoustic impedance mismatch between the piezoelectric ceramic and the metal shell of the equipment, resulting in large ultrasonic signal energy loss and low signal-to-noise ratio. At the same time, it may not optimize the performance according to the signal characteristics of different equipment, and it is difficult to meet the diverse detection requirements.

[0004] Problems existing in the prior art solutions: There are problems such as easy detachment of electrode welding and insufficient anti-interference ability, which affect the signal detection sensitivity and accuracy, and the installation is restricted by the size and structure of GIS equipment, with a narrow application range; there is an acoustic impedance mismatch between the piezoelectric ceramic and the metal shell of the equipment, resulting in large ultrasonic signal energy loss and low signal-to-noise ratio, and it is difficult to meet the diverse detection requirements. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned technical problems existing in the prior art that multiple independent sensors need to be used to detect ultrasonic and electromagnetic signals respectively, with problems such as complex equipment, high cost, and poor signal synchronization, and to provide an ultrasonic-UHF integrated sensor combining a piezoelectric unit and a patterned circuit.

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

[0007] An ultrasonic-UHF integrated sensor in which a piezoelectric unit is combined with a patterned circuit, the integrated sensor comprising an ultrasonic unit and an UHF unit arranged in a cavity multi-band resonant cavity, and a signal acquisition circuit connected to the ultrasonic unit and the UHF unit signals;

[0008] The ultrasonic unit and the ultra-high frequency unit are integrated on the same substrate using an orthogonal, non-planar stacking structure; the ultrasonic unit includes a piezoelectric sheet arranged on the substrate and a gradient acoustic matching layer arranged on a side of the substrate away from the piezoelectric sheet; the ultra-high frequency unit includes a piezoelectric substrate arranged on the substrate and a patterned circuit with a defective ground structure etched on the surface of the piezoelectric substrate away from the substrate.

[0009] As a preferred technical solution, the gradient acoustic matching layer is specifically a three-layer gradient acoustic matching layer composed of silicone rubber, aluminum nitride ceramics and tungsten powder epoxy resin arranged in sequence from the side close to the piezoelectric sheet to the side far away from the piezoelectric sheet.

[0010] As a preferred technical solution, the piezoelectric sheet adopts lead magnesium niobate PMN-PT single crystal piezoelectric sheet.

[0011] As a preferred technical solution, the ultrasonic unit is integrated with a platinum thin film temperature sensor and a dynamic gain compensation circuit.

[0012] As a preferred technical solution, the patterned circuit adopts a fractal spiral gradient structure, and an asymmetric gradient spiral copper wire is formed on the surface of the piezoelectric substrate by laser etching. The center of the spiral is connected to the RF port, and the outer edge is grounded through a through-hole array.

[0013] As a preferred technical solution, the line width of the asymmetric gradient spiral copper wire gradually changes from 0.1 mm to 0.5 mm, and the pitch changes according to an exponential law.

[0014] As a preferred technical solution, the defective ground structure is specifically as follows: a distributed LC resonant branch is loaded at the end of the asymmetric tapered spiral copper wire to excite multiple resonance points to enhance the out-of-band suppression of the communication interference frequency band.

[0015] As a preferred technical solution, a metal isolation wall is provided between the ultrasonic unit and the UHF unit.

[0016] As a preferred technical solution, the signal acquisition circuit includes:

[0017] A preamplifier amplifies the output signals of the ultrasonic unit and the UHF unit, and matches the impedance of the ultrasonic unit and the UHF unit with the impedance of the detection signal receiver;

[0018] Detecting signal receivers to collect ultrasonic signal and UHF signal data;

[0019] Signal processor, separating ultrasonic signal and UHF signal.

[0020] As a preferred technical solution, the steps of the signal processor processing the ultrasonic and UHF signals include:

[0021] Preprocessing the collected ultrasonic and UHF mixed signals, and using multi-scale wavelet decomposition to decompose the preprocessed mixed signals into different frequency sub-bands, including high-frequency sub-bands and low-frequency sub-bands;

[0022] For ultrasonic and UHF signals, the energy characteristics of the corresponding sub-bands, the standard deviation of the wavelet coefficients and other characteristic quantities are extracted respectively to obtain the ultrasonic signal characteristics of the low-frequency sub-band and the UHF signal characteristics of the high-frequency sub-band;

[0023] The extracted ultrasonic signal features and UHF signal features are fused to form a comprehensive feature vector as the input of the neural network;

[0024] The ultrasonic signal characteristics of the signal to be detected are input into the trained neural network, and the neural network outputs the prediction result of the operating status of the equipment.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1) The present invention provides an ultrasonic-UHF integrated sensor combining a piezoelectric unit and a patterned circuit. Based on the piezoelectric ultrasonic sensing principle and the patterned planar UHF sensing principle, an orthogonal non-planar stacking structure is adopted to divide the piezoelectric sheet into a vertical ultrasonic sensing unit and a horizontal UHF coupling unit. The two are integrated on the same substrate in a multi-band resonant cavity, and electromagnetic crosstalk suppression is achieved through a metal isolation wall, so that the sensor can sense ultrasonic and UHF signals at the same time, breaking through the time and space asynchronous defects of independent sensor split collection, and improving the synchronization and accuracy of signal monitoring.

[0027] 2) The ultrasonic unit proposed in the present invention is based on the vibration mode of the PMN-PT single crystal and the gradient acoustic matching layer. The ultrasonic unit is loaded with a gradient dielectric layer to broaden the broadband matching range and improve the ultrasonic transmission efficiency.

[0028] 3) The UHF unit proposed in the present invention replaces the traditional radiation reception with coplanar waveguide near-field coupling. The fractal spiral gradient structure electrode is etched on the surface of the UHF unit. The spiral fractal structure extends the effective electrical length through spatial coupling, thereby improving the UHF signal reception sensitivity. The gradient line width and branch loading can suppress surface wave loss, and concentrate the electric field energy to the polarization direction of the piezoelectric film through the electromagnetic field localization effect, thereby realizing the directional coupling of ultrasonic-electromagnetic dual-mode energy. And through defect etching and electromagnetic shielding cavity, a 300MHz-3GHz wide-band response and 70dB shielding effectiveness are achieved.

[0029] 4) The present invention combines ultrasonic pulse triggering and FPGA dynamic delay compensation to achieve dual-mode signal synchronization, realizes the time-domain correlation between ultrasonic mechanical waves and ultra-high frequency electromagnetic pulses, and combines a dynamic delay locked loop to compensate for temperature drift, reducing the alignment error of dual-mode signals, and can improve the discharge recognition rate under strong interference. Description of the Drawings

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0031] Figure 1 Schematic connection diagram of an ultrasonic-ultra-high frequency integrated sensor combining a piezoelectric unit and a patterned circuit provided by an embodiment of the present invention;

[0032] Figure 2 Schematic structural diagram of an ultrasonic-ultra-high frequency integrated sensor combining a piezoelectric unit and a patterned circuit provided by an embodiment of the present invention;

[0033] Figure 3 Schematic structural diagram of the patterned circuit of an ultrasonic-ultra-high frequency integrated sensor combining a piezoelectric unit and a patterned circuit provided by an embodiment of the present invention;

[0034] The meanings of the reference numerals are as follows: 1, ultrasonic unit; 11, piezoelectric sheet, 12, silicone rubber, 13, aluminum nitride ceramic, 14, tungsten powder epoxy resin, 2, ultra-high frequency unit; 21, patterned circuit; 3, preamplifier; 4, detection signal receiver; 5, signal processor; 6, metal isolation plate; 7, substrate. Detailed Embodiments

[0035] The present invention will be described in detail below with reference to the drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and gives detailed implementation manners and specific operation processes, but the protection scope of the present invention is not limited to the following embodiments.

[0036] Embodiment 1

[0037] The present invention provides an ultrasonic-UHF integrated sensor combining a piezoelectric unit and a patterned circuit. Based on the piezoelectric ultrasonic sensing principle and the patterned planar UHF sensing principle, the ultrasonic sensing unit and the UHF sensing unit are combined to achieve an integrated function. Through this integrated design, the sensor can sense ultrasonic and UHF signals at the same time, improving the synchronization and accuracy of signal monitoring, and solving the technical problems of the traditional monitoring method using multiple independent sensors to detect ultrasonic and electromagnetic signals respectively, such as complex equipment, high cost and poor signal synchronization.

[0038] like Figure 1 As shown, an ultrasonic-UHF integrated sensor combining a piezoelectric unit and a patterned circuit provided in an embodiment of the present invention includes: an ultrasonic unit 1, an UHF unit 2, a preamplifier 3, a detection signal receiver 4, and a signal processor 5.

[0039] The ultrasonic-UHF integrated sensor in this application breaks through the limitations of traditional single-mode sensing and adopts an orthogonal stacking structure: it is divided into a vertical ultrasonic sensing unit and a horizontal UHF coupling unit, and the two are integrated on the same substrate 7 in the multi-band resonant cavity. Figure 2 As shown, the ultrasonic unit 1 is loaded with a gradient dielectric layer to broaden the broadband matching range, stacked along the z-axis direction, and responds to vertical ultrasonic vibrations; the UHF unit 2 is located on the surface of the substrate 7 (xy plane), responds to horizontal electromagnetic signals, and a fractal spiral gradient structure electrode is etched on the surface to improve sensitivity. A metal isolation wall 6 is set between the ultrasonic unit 1 and the UHF unit 2 to separate the two and suppress electromagnetic crosstalk. The time domain correlation of the ultrasonic mechanical wave and the UHF electromagnetic pulse is realized through the dual-mode synchronous trigger circuit, combined with the dynamic delay lock loop to compensate for the temperature drift, the hardware-level timing calibration, the delay deviation caused by the temperature drift, and the dual-mode signal alignment error are reduced, and finally the discharge recognition rate is improved under strong interference.

[0040] The two units of the integrated sensor are different in structure or principle from the existing independent sensors: In terms of structure, the dual-mode sensor unit is integrated into a 25mm×10mm space, and the electromagnetic crosstalk suppression under a 25mm spacing is achieved through the metal isolation wall 6, which is smaller than the split sensor and does not require an independent interface. In terms of principle, the ultrasonic unit is based on the vibration mode and gradient acoustic matching layer of the PMN-PT single crystal; the UHF unit replaces the traditional radiation reception through coplanar waveguide near-field coupling, and combines ultrasonic pulse triggering with FPGA dynamic delay compensation, digital algorithm-level synchronization, and adjusts the acquisition timing of ultrasonic and UHF signals, breaking through the time and space asynchronous defects of the independent sensor split acquisition.

[0041] The ultrasonic unit 1, based on the piezoelectric ultrasonic sensing principle, can convert ultrasonic vibrations into electrical signals. When an ultrasonic signal acts on the piezoelectric sheet 11, it will generate mechanical deformation. Due to the piezoelectric effect, this mechanical deformation will be converted into corresponding charge or voltage changes, thus realizing the perception and conversion of ultrasonic signals, enabling the sensor to detect signals in the ultrasonic frequency band.

[0042] As Figure 2 shown, in the ultrasonic unit 1, it includes a piezoelectric sheet 11. On one side of the piezoelectric sheet 11, there is a three-layer gradient acoustic matching layer composed of silicone rubber 12 - aluminum nitride ceramic 13 - tungsten powder epoxy resin 14 arranged in sequence, which improves the ultrasonic transmission efficiency. At the same time, a platinum thin-film temperature sensor and a dynamic gain compensation circuit are integrated in the ultrasonic unit 1. The amplitude of the analog circuit level is stable, compensating for the ultrasonic signal fluctuation caused by temperature drift, and can reduce the temperature drift coefficient to 0.08% / °C.

[0043] In this embodiment, the piezoelectric sheet 11 is preferably a lead magnesium niobate (PMN-PT) single-crystal piezoelectric sheet, which has a high electromechanical coupling coefficient. This means that it can effectively convert mechanical energy into electrical energy and electrical energy into mechanical energy. For the piezoelectric sheet in the ultrasonic-ultra-high frequency integrated sensor, a high electromechanical coupling coefficient helps to improve the conversion efficiency of ultrasonic signals, enabling the piezoelectric sheet to more sensitively perceive ultrasonic vibrations and convert them into electrical signals. At the same time, it can also better convert electrical signals into ultrasonic vibrations in the inverse piezoelectric effect, ensuring the ultrasonic detection performance of the sensor.

[0044] The ultra-high frequency unit 2 has a piezoelectric substrate (PZT-5H) arranged on the substrate 7, and a patterned circuit 21 is etched on the surface of the piezoelectric substrate. It realizes a broadband response of 300 MHz - 3 GHz and a shielding effectiveness of 70 dB through defected ground (DGS) and an electromagnetic shielding cavity. Combining a superheterodyne receiver and a surface acoustic wave filter reduces the equivalent noise power. By optimizing material characteristics, spatial electromagnetic isolation, and cross-domain synchronization algorithms, it breaks through the performance bottleneck of traditional split sensors.

[0045] The patterned circuit 21 is preferably a patterned circuit with a coplanar waveguide (CPW) structure, as Figure 3As shown, the patterned circuit of the coplanar waveguide structure adopts a fractal spiral gradient structure. An asymmetric gradient spiral copper wire (with the line width gradually changing from 0.1 mm to 0.5 mm and the pitch changing according to an exponential law) is formed on the surface of the piezoelectric substrate (PZT-5H) of the ultra-high frequency unit through laser etching. The center of the spiral is connected to the RF port, and the outer edge is grounded through a via array to achieve broadband impedance matching in the range of 0.3 - 3.5 GHz (standing wave ratio ≤ 1.5). At the same time, a distributed LC resonant stub (L = 2 nH, C = 0.5 pF) is loaded at the end of the spiral to excite multiple resonant points to enhance the out-of-band rejection (> 40 dB) in the 2.4 GHz / 5.8 GHz communication interference bands. The principle lies in that: the spiral fractal structure extends the effective electrical length through spatial coupling, improving the receiving sensitivity of ultra-high frequency signals, while the gradually changing line width and stub loading can suppress surface wave losses, and through the electromagnetic field localization effect, the electric field energy is concentrated in the polarization direction of the piezoelectric sheet, realizing the directional coupling of ultrasonic-electromagnetic dual-mode energy.

[0046] The coplanar waveguide patterned circuit 21 with the fractal spiral gradient structure has good electromagnetic transmission characteristics, can achieve low-loss and high-efficiency signal transmission in the ultra-high frequency band, and helps to improve the detection ability of the sensor for weak ultra-high frequency signals. Its planar structure is convenient for integration with other electronic components, such as preamplifiers and detection signal receivers, which is conducive to the miniaturization and integrated design of the sensor; by changing parameters such as the width, length, and dielectric material of the coplanar waveguide, its impedance characteristics and electromagnetic response characteristics can be flexibly adjusted, enabling it to better match the requirements of the ultra-high frequency sensing unit and work well in coordination with other parts of the entire sensor system; the coplanar waveguide structure is relatively enclosed, which can reduce the influence of external electromagnetic interference on the sensor signal to a certain extent, improving the stability and reliability of the sensor.

[0047] The preamplifier 3. The ultrasonic electrical signals output from the piezoelectric sheet 11 and the ultra-high frequency electrical signals output from the patterned circuit 21 are usually very weak and difficult to directly perform subsequent processing and analysis. There may be impedance mismatches between the ultrasonic unit 1, the ultra-high frequency unit 2, and the detection signal receiver 4, which will cause reflections and losses during signal transmission, affecting the signal transmission efficiency. The preamplifier 3 can play a role in impedance matching, matching the impedance of the input signal source (ultrasonic unit 1 and ultra-high frequency unit 2) with the impedance of the output load (detection signal receiver 4), enabling the signal to be transmitted more efficiently from the signal source to the detection signal receiver, reducing signal loss, and improving the performance of the entire sensor system.

[0048] The detection signal receiver 4 can process both ultrasonic and UHF signals simultaneously, enabling the sensor system to monitor phenomena such as partial discharge from multiple dimensions. By comprehensively analyzing the characteristics of the two signals, the operating state of the equipment can be judged more accurately, potential fault hazards can be discovered, and the comprehensiveness and accuracy of monitoring can be improved.

[0049] The signal processor 5, since the ultrasonic signal and the UHF signal are in different frequency ranges, utilizes this characteristic and extracts the two mixed signals separately through specific filtering algorithms and other means. By accurately separating the ultrasonic and UHF signals and performing data conversion on them, external devices can more precisely obtain the characteristic information of phenomena such as partial discharge in different frequency ranges, thereby improving the accuracy of judging the operating state of transformer equipment and more accurately discovering potential transformer fault hazards.

[0050] When the ultrasonic signal propagates to the piezoelectric sheet 11, the piezoelectric sheet 11 operates based on the piezoelectric ultrasonic sensing principle. The ultrasonic vibration causes the piezoelectric sheet 11 to generate mechanical deformation, and due to the piezoelectric effect, this mechanical deformation is converted into a corresponding charge or voltage change, thus converting the ultrasonic vibration into an electrical signal. At the same time, the UHF electromagnetic pulse signal is incident on the patterned circuit 21, and according to the patterned planar UHF sensing principle and the electromagnetic induction principle, an induced current and voltage are generated in the patterned circuit 21. The ultrasonic electrical signal output from the piezoelectric sheet 11 and the UHF electrical signal output from the patterned circuit 21 are usually relatively weak. The preamplifier 3 amplifies these two weak signals, raises the signals to an appropriate amplitude level, suppresses noise and interference signals through filtering and other means, and improves the signal quality and signal-to-noise ratio. The ultrasonic and UHF electrical signals processed by the preamplifier 3 are transmitted to the detection signal receiver 4. The detection signal receiver 4 accurately collects the data of these two signals and outputs them to the signal processor 5. The signal processor 5 extracts the two mixed signals separately through specific filtering algorithms and other means and transmits them to external devices such as computers and monitoring systems. After receiving the data, the external devices use professional data analysis software and algorithms to deeply analyze the ultrasonic and UHF signal data.

[0051] This application is based on the piezoelectric ultrasonic method and the patterned planar UHF sensing principle, and organically combines the ultrasonic sensing unit and the UHF sensing unit. This combination method emphasizes the collaborative work of the two sensing principles more, and through specific design, the functions of the sensors are more closely integrated, improving the synchronization and accuracy of signal monitoring.

[0052] By comprehensively analyzing the characteristics of the two signals, the operating state of the monitored object such as power equipment can be evaluated more comprehensively and accurately, potential fault hazards can be discovered in a timely manner, providing a strong basis for equipment maintenance and management, thereby realizing the effective monitoring and early warning of phenomena such as partial discharge and ensuring the safe and stable operation of the equipment.

[0053] Example 2

[0054] As another implementation manner of the present invention, on the basis of the ultrasonic-UHF integrated sensor combining the piezoelectric unit and the patterned circuit provided in Example 1, further, the specific process of the signal processor 5 for separating the ultrasonic and UHF signals is as follows.

[0055] Step 1, perform denoising processing on the ultrasonic and UHF mixed signals collected by the ultrasonic-UHF integrated sensor, and use mean filtering to remove the random noise in the signals to improve the signal quality.

[0056] Step 2, perform normalization processing to map the signal amplitude to the interval [0,1], so that signals with different amplitude ranges are comparable and facilitate subsequent analysis.

[0057] Step 3, select a suitable wavelet basis function, such as the db4 wavelet, and perform multi-scale wavelet decomposition on the preprocessed signal.

[0058] Step 4, the decomposed signal is divided into different frequency sub-bands, including high-frequency sub-bands and low-frequency sub-bands.

[0059] Step 5, according to the frequency characteristics of the ultrasonic and UHF signals, extract corresponding feature quantities such as the energy characteristics of the sub-bands and the standard deviation of the wavelet coefficients. For example, the ultrasonic signal is mainly concentrated in the low-frequency band, and the characteristics of the low-frequency sub-band are mainly analyzed; the UHF signal is in the high-frequency band, and the characteristics of the high-frequency sub-band are concerned.

[0060] Step 6, fuse the extracted ultrasonic and UHF signal features to form a comprehensive feature vector. That is, in a series connection manner, the feature vectors of the ultrasonic signal and the UHF signal are connected in sequence as the input of the neural network.

[0061] Step 7, construct a multi-layer perceptron (MLP) neural network model. The network includes an input layer, a hidden layer, and an output layer. The number of nodes in the input layer is the same as the dimension of the comprehensive feature vector, and the number of nodes in the output layer is determined according to the classification task. For example, to judge the normal operation, minor faults, severe faults, etc. of the device, different output nodes can correspond respectively.

[0062] Step 8, use a large number of sample data with known device operating states to train the neural network, and use the backpropagation algorithm to adjust the weights and thresholds of the network so that the network can accurately learn the mapping relationship between the features and the device operating states.

[0063] Step 9, input the signal to be detected after the above processing into the trained neural network, and the network outputs the prediction result of the device operating state.

[0064] Step 10: By comparing with the actual situation, evaluate indicators such as the accuracy and recall rate of the algorithm, continuously optimize the algorithm parameters, and improve the algorithm performance.

[0065] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative efforts. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field according to the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the existing technology should fall within the protection scope determined by the claims.

Claims

1. An integrated ultrasonic-UHF sensor combining a piezoelectric element and a patterned circuit, characterized in that, The integrated sensor comprises an ultrasonic unit (1) and an ultra-high frequency unit (2) arranged in a multi-band resonant cavity of a cavity, and a signal acquisition circuit connected to the ultrasonic unit (1) and the ultra-high frequency unit (2); The ultrasonic unit (1) and the ultra-high frequency unit (2) are integrated on the same substrate (7) using an orthogonal, non-planar stacking structure; the ultrasonic unit (1) comprises a piezoelectric sheet (11) arranged on the substrate (7) and a gradient acoustic matching layer arranged on a side of the substrate (7) away from the piezoelectric sheet (11); the ultra-high frequency unit (2) comprises a piezoelectric substrate arranged on the substrate (7) and a patterned circuit having a defective ground structure etched on the surface of the piezoelectric substrate on a side away from the substrate (7).

2. The ultrasonic-UHF integrated sensor combining a piezoelectric unit and a patterned circuit according to claim 1, characterized in that The gradient acoustic matching layer is specifically a three-layer gradient acoustic matching layer composed of silicone rubber (12), aluminum nitride ceramic (13) and tungsten powder epoxy resin (14) arranged in sequence from the side close to the piezoelectric sheet (11) to the side far from the piezoelectric sheet (11).

3. The integrated ultrasonic-UHF sensor combining a piezoelectric unit and a patterned circuit according to claim 1, wherein The piezoelectric sheet (11) is a lead magnesium niobate PMN-PT single crystal piezoelectric sheet.

4. The integrated ultrasonic-UHF sensor combining a piezoelectric unit and a patterned circuit according to claim 1, wherein The ultrasonic unit (1) is integrated with a platinum thin film temperature sensor and a dynamic gain compensation circuit.

5. The ultrasonic-UHF integrated sensor combining a piezoelectric unit and a patterned circuit according to claim 1, characterized in that The patterned circuit adopts a fractal spiral gradient structure, and an asymmetric gradient spiral copper wire is formed on the surface of the piezoelectric substrate by laser etching. The center of the spiral is connected to the radio frequency port, and the outer edge is grounded through a through-hole array.

6. The integrated ultrasonic-UHF sensor combining a piezoelectric unit and a patterned circuit according to claim 5, characterized in that The line width of the asymmetric gradient spiral copper wire gradually changes from 0.1 mm to 0.5 mm, and the pitch changes according to an exponential law.

7. The integrated ultrasonic-UHF sensor combining a piezoelectric unit and a patterned circuit according to claim 5, characterized in that, The defective structure is specifically as follows: a distributed LC resonance branch is loaded at the end of the asymmetric tapered spiral copper wire to excite multiple resonance points to enhance the out-of-band suppression of the communication interference frequency band.

8. The integrated ultrasonic-UHF sensor combining a piezoelectric unit and a patterned circuit according to claim 1, wherein A metal isolation wall (6) is provided between the ultrasonic unit (1) and the ultra-high frequency unit (2).

9. The ultrasonic-UHF integrated sensor combining a piezoelectric unit and a patterned circuit according to claim 1, wherein The signal acquisition circuit comprises: A preamplifier (3) amplifies the output signals of the ultrasonic unit (1) and the ultra-high frequency unit (2), and matches the impedance of the ultrasonic unit (1) and the ultra-high frequency unit (2) with the impedance of the detection signal receiver (4); A detection signal receiver (4) for collecting ultrasonic signal and UHF signal data; The signal processor (5) separates the ultrasonic signal and the ultra-high frequency signal.

10. The ultrasonic-UHF integrated sensor combining a piezoelectric unit and a patterned circuit according to claim 9, wherein The steps of the signal processor (5) processing the ultrasonic and ultra-high frequency signals include: Preprocessing the collected ultrasonic and UHF mixed signals, and using multi-scale wavelet decomposition to decompose the preprocessed mixed signals into different frequency sub-bands, including high-frequency sub-bands and low-frequency sub-bands; For ultrasonic and UHF signals, the energy characteristics of the corresponding sub-bands, the standard deviation of the wavelet coefficients and other characteristic quantities are extracted respectively to obtain the ultrasonic signal characteristics of the low-frequency sub-band and the UHF signal characteristics of the high-frequency sub-band; The extracted ultrasonic signal features and UHF signal features are fused to form a comprehensive feature vector as the input of the neural network; The ultrasonic signal characteristics of the signal to be detected are input into the trained neural network, and the neural network outputs the prediction result of the operating status of the equipment.

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