Integrated three-order PT symmetrical high-sensitivity wireless sensor circuit device

Abstract

The invention provides an integrated third-order PT symmetric high-sensitivity wireless sensor circuit device, and researches a wireless sensing circuit device based on a third-order EP point based on a new progress of non-Hermite physics and space time (PT) symmetry, and the wireless sensing circuit device is used for improving the detection sensitivity of the mixing degree of coal gangue. According to the circuit device, a circuit model meeting the three-order EP point condition is designed, and the LC resonance principle is utilized, so that high-sensitivity response to small changes is achieved. Compared with a traditional second-order PT symmetric system, the integrated third-order PT symmetric high-sensitivity wireless sensor circuit device provided by the invention has the advantages that the third-order PT symmetric system has a higher sensitivity enhancement factor when monitoring the mixing degree of the coal gangue, and particularly, the sensitivity enhancement factor is more obvious when the mixing degree of the coal gangue with low content is monitored. According to the technical scheme, the yield and quality of coal are improved, coordinated development and safe and efficient utilization of coal resources are promoted, and the method has important significance in promoting technical progress of the coal industry.

Description

Technical Field

[0001] The present invention relates to the field of wireless sensors, and in particular to an integrated three-order PT symmetric high-sensitivity wireless sensor circuit device. Background Art

[0002] China is rich in coal resources and has a large reserve of thick coal seams. Thick coal seams are the main coal seams for China to achieve high-yield and efficient mining. Currently, three methods are mainly used for mining: layering, top coal caving, and large mining height. Among them, the top coal caving method has the highest working efficiency.

[0003] The top coal caving mining mainly consists of two parts: coal cutting by the front-end coal mining machine and coal caving by the rear-end hydraulic support. The front-end coal mining automatic control can be realized by the coal mining machine memory cutting and the hydraulic support automatic control. However, the comprehensive caving part at the rear end of the comprehensive mining top coal caving working face is located in the goaf behind the hydraulic support, and the dust near the coal caving port is large and the line of sight is unclear. It is usually mainly controlled by manual operation. The operator needs to judge whether it is coal or gangue to be caved, and determine whether the top coal is caved. It will inevitably lead to over-caving or under-caving in the caving process. Over-caving will lead to a decrease in coal quality, and under-caving will reduce the coal recovery rate. The monitoring of gangue in the caving process has become a prominent problem that restricts the safe and efficient mining of thick coal seams and the coordinated development of coal resources. Therefore, it is crucial to realize high-sensitivity detection of the mixing degree of gangue in the caving process to improve the coal recovery rate and improve the coal quality.

[0004] Wireless sensor technology (WS) can perform non-contact continuous monitoring tasks in harsh or closed environments where wired connections cannot be achieved. Since Collins first used a micro-spiral inductor (L) and a piezoceramic capacitor (C) to construct an implantable intraocular pressure sensor in 1967, passive wireless sensor technology based on the LC resonance principle has experienced rapid development in the past few decades and has been widely used in industry (such as tire pressure monitoring, radio frequency identification) and medicine (such as bone healing detection, physiological monitoring). The working principle of these passive LC sensors usually relies on the shift of the resonant frequency, that is, the change of the measured parameters (such as pressure, stress, temperature, humidity, etc.) causes the detuning of the capacitor or inductor elements. However, when the change amplitude of the measured parameter is small, the shift of the resonant frequency is also relatively small. Therefore, studying a strategy to amplify the resonant frequency shift caused by these small changes is of great significance to improve the sensitivity of the sensor. Therefore, we propose an integrated third-order PT symmetric high-sensitivity wireless sensor circuit device. Summary of the invention

[0005] The purpose of the present invention is to solve the problems in the existing background technology. In order to achieve the above invention purpose, the present invention provides the following technical solutions: an integrated three-order PT symmetrical high-sensitivity wireless sensor circuit device, including a lumped resonant unit, a distributed resonant unit and two bypass capacitors, the lumped resonant unit includes a lumped inductor L1 and a lumped capacitor C1, a lumped inductor L3 and a parallel plate capacitor C3, the distributed resonant unit includes a lumped inductor L2 and a lumped capacitor C2, and the bypass capacitor includes a lumped capacitor C0.

[0006] As a preferred technical solution of the present invention, it includes detailed information of its various components; the lumped inductor L1, the lumped inductor L2 and the lumped inductor L3 are annular FeSiAl inductors with a current resistance of 10A, and the pins at both ends of the inductor are 1mm; the bypass capacitor C0, the lumped capacitor C1 and the lumped capacitor C2 are metallized polyester film direct-insertion lumped capacitors with a voltage resistance of 250V.

[0007] As a preferred technical solution of the present invention, it also includes a parallel plate capacitor C3, which is composed of two aluminum plates with a thickness of 1 mm, a length of 40 mm, and a width of 30 mm, and the interval between the two aluminum plates is 40 mm; except for the parallel plate capacitor, all other components are integrated on the PCB board.

[0008] As a preferred technical solution of the present invention, the parameters of the inductor and the capacitor are respectively set as follows:

[0009] L1=L2=L3=L≈0.73mH;

[0010] When C0 changes, the adjustment of C1 always satisfies the relationship C1=CC0 / (C0-C), and the adjustment of C2 always satisfies the relationship C2=CC0 / (C0-2C), where C≈4.76nF is a constant.

[0011] As a preferred technical solution of the present invention, Port 1 of the vector network analyzer VNA serves as an AC source, one end of the lumped inductor L1 away from the bypass capacitor C0 and one end of the lumped capacitor C1 away from the bypass capacitor C0 are connected in series with the AC source, and one end of the lumped inductor L3 away from the bypass capacitor C0 and one end of the parallel plate capacitor C3 away from the bypass capacitor C0 are connected in series with Port 2 of the vector network analyzer.

[0012] As a preferred technical solution of the present invention, Port 2 of the vector network analyzer is used as a load; a first end of a bypass capacitor C0 is connected between the lumped capacitor C1 and the lumped inductor L1, and a second end is connected between the lumped capacitor C2 and the lumped inductor L2; a first end of another bypass capacitor C0 is connected between the lumped capacitor C2 and the lumped inductor L2, and a second end is connected between the flat plate capacitor C3 and the lumped inductor L3; and mixed samples of coal gangue in different proportions are placed between the two plates of the parallel plate capacitor.

[0013] As a preferred technical solution of the present invention, the influence of different proportions of coal gangue mixed samples on a single resonant coil wireless sensor system is used to stabilize the system at the resonant frequency, and the reflection spectrum of the passive wireless sensor system under different coal gangue mixing ratios is measured, and the resonant frequency f is extracted respectively. n and frequency offset |f n -f0|, the perturbation intensity ε acting on the frequency, and the curve of different coal gangue contents, and it is obtained:

[0014]

[0015] Where L1 is the lumped inductor, C1 is the capacitance of the parallel plate capacitor, and C n (the subscripts correspond to the serial numbers in Table 1) represent the varying capacitance caused by different contents of gangue;

[0016] And from the above formula, we can know the following linear relationship:

[0017] ε~|f n -f0|~C n

[0018] Where ε represents the perturbation intensity, |f n -f0|Frequency offset, C n Indicates the changing capacitance caused by different contents of coal gangue.

[0019] As a preferred technical solution of the present invention, by synthesizing the lumped inductance L1, lumped inductance L2, lumped inductance L3, bypass capacitor C0, lumped capacitor C1 and lumped capacitor C2 in the third-order PT symmetric circuit, according to KVL, it can be obtained

[0020]

[0021] Where Z1=iωL1+1 / (iωC1), Z2=iωL2+1 / (iωC2), Z3=iωL3+1 / (iωC3);

[0022] Among them, L1 represents the lumped inductance L1, the lumped inductance L2 and the lumped capacitance C1, and the lumped inductance L3.

[0023] As a preferred technical solution of the present invention, according to the symmetry of the structure: L1 = L, C1 = C3, C2 = CC 00 / (C 00 -2C), C 00 =C 01 , R1=R, using the approximate condition The simplified equation is:

[0024]

[0025] in The coupling strengths are γ = R / (2L) and κ = ω0C / (2C 00 ).

[0026] As a preferred technical solution of the present invention, the eigenfrequency can be obtained by solving the equation:

[0027] ω1=ω0,

[0028] The ideal third-order PT symmetry is obtained through the above equations, when κ and γ satisfy the critical relationship When , the three eigenfrequencies are combined at ω0, and the circuit works in the EP3 state.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows: In the scheme of the present invention: In the top coal caving mining technology, China has achieved high-yield and high-efficiency mining by utilizing its abundant coal resources. For thick coal seam mining, layering, top caving and large mining height methods are adopted, among which the top coal caving method is widely used due to its high efficiency. However, there are problems of unclear vision and large dust in the comprehensive caving link at the rear end of the top coal caving working face, which makes the operation rely on manual judgment, affecting the coal recovery rate and quality. To solve this problem, wireless sensor technology is introduced to achieve non-contact continuous monitoring.

[0030] Based on the new progress of non-Hermitian physics and parity-time (PT) symmetry, a wireless sensing system based on the third-order EP point is studied to improve the detection sensitivity of the mixture of coal gangue. The system achieves high sensitivity response to small changes by designing a circuit model that meets the third-order EP point conditions and using the LC resonance principle. The experimental results show that compared with the traditional second-order PT symmetric system, the third-order PT symmetric system has a higher sensitivity enhancement factor when monitoring the mixture ratio of coal gangue, especially when the content of coal gangue is low. In summary, the technical solution of the present invention not only improves the recovery rate and quality of coal, but also promotes the coordinated development and safe and efficient utilization of coal resources, which is of great significance to promoting technological progress in the coal industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1It is a structural schematic diagram of the wireless sensing system for coal gangue mixing degree based on synthetic third-order PT symmetry of the present invention;

[0032] Figure 2 It is a circuit schematic diagram based on synthetic third-order PT symmetry of the present invention;

[0033] Figure 3 (a) Reflection spectra of a single resonant coil wireless sensor system at different perturbation intensities ε;

[0034] Figure 3(b) Resonance frequency f n (The small disturbance ε acting at the frequency) changes with different gangue contents;

[0035] Figure 3(c) Frequency offset |f n -f0|(a small disturbance ε acting at a frequency) changes with different gangue contents. The red curve is a first-order linear curve.

[0036] FIG4( a ) is a reflection spectrum diagram of the synthetic third-order PT symmetric wireless sensing system of the present invention at different perturbation intensities ε;

[0037] FIG4(b) is a diagram of the present invention for extracting the resonant frequency |f n ′-f0′| Experimental results at different perturbation intensities ε, the red curve is ε 1 / 3 Theoretical calculation results of

[0038] Figure 4(c) shows the result of (b) on a logarithmic scale, with the red curve being y=ε 1 / 3 A straight line graph of

[0039] Figure 5 The structural diagram of the wireless sensing system for coal gangue mixing degree based on synthetic second-order PT symmetry;

[0040] Fig. 6 (a) Reflection spectra of the synthetic second-order PT symmetric wireless sensing system at different perturbation intensities ε;

[0041] Figure 6(b) Extracting the resonant frequency |f n ′-f0′| Experimental results at different perturbation intensities ε, the red curve is ε 1 / 2 Theoretical calculation results of

[0042] Figure 6(c) shows the result of (b) on a logarithmic scale, with the red curve being y=ε 1 / 2 A straight line graph of

[0043] Figure 7 Wireless sensing monitoring system for gangue mixing degree based on synthetic third-order PT symmetry and synthetic second-order PT symmetry Sensitivity enhancement factor of the system at different gangue contents |f n ′-f0′| / ε graph. DETAILED DESCRIPTION

[0044] To make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be described clearly and completely in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

[0045] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely represents some embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. It should be noted that the embodiments of the present invention and the features and technical solutions in the embodiments can be combined with each other without conflict. It should be noted that similar numbers and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0046] Embodiment 1: An integrated three-order PT symmetrical high-sensitivity wireless sensor circuit device includes a lumped resonant unit, a distributed resonant unit and two bypass capacitors, wherein the lumped resonant unit includes a lumped inductor L1 and a lumped capacitor C1, a lumped inductor L3 and a parallel plate capacitor C3, the distributed resonant unit includes a lumped inductor L2 and a lumped capacitor C2, and the bypass capacitor includes a lumped capacitor C0. Detailed information of each component is also included; the lumped inductor L1, the lumped inductor L2 and the lumped inductor L3 are annular FeSiAl inductors with a current resistance of 10A, and the pins at both ends of the inductor are 1mm; the bypass capacitor C0, the lumped capacitor C1 and the lumped capacitor C2 are metallized polyester film plug-in lumped capacitors with a voltage resistance of 250V.

[0047] The parallel plate capacitor C3 is composed of two aluminum plates with a thickness of 1 mm, a length of 40 mm, and a width of 30 mm, and the interval between the two aluminum plates is 40 mm; other components except the parallel plate capacitor are integrated on the PCB board.

[0048] The parameters of the inductor and capacitor are set as follows:

[0049] L1=L2=L3=L≈0.73mH;

[0050] When C0 changes, the adjustment of C1 always satisfies the relationship C1=CC0 / (C0-C), and the adjustment of C2 always satisfies the relationship C2=CC0 / (C0-2C), where C≈4.76nF is a constant.

[0051] Port 1 of the vector network analyzer VNA is used as an AC source, one end of the lumped inductor L1 away from the bypass capacitor C0 and one end of the lumped capacitor C1 away from the bypass capacitor C0 are connected in series with the AC source, and one end of the lumped inductor L3 away from the bypass capacitor C0 and one end of the parallel plate capacitor C3 away from the bypass capacitor C0 are connected in series with Port 2 of the vector network analyzer.

[0052] Port 2 of the vector network analyzer is used as a load; a first end of a bypass capacitor C0 is connected between the lumped capacitor C1 and the lumped inductor L1, and a second end is connected between the lumped capacitor C2 and the lumped inductor L2; a first end of another bypass capacitor C0 is connected between the lumped capacitor C2 and the lumped inductor L2, and a second end is connected between the flat plate capacitor C3 and the lumped inductor L3; coal gangue mixed samples of different proportions are placed between the two plates of the parallel plate capacitor.

[0053] Through the influence of different proportions of coal gangue mixed samples on a single resonant coil wireless sensor system, the system is stabilized at the resonant frequency, the reflection spectrum of the passive wireless sensor system under different coal gangue mixing ratios is measured, and the resonant frequency f is extracted respectively. n and frequency offset |f n -f0|, the perturbation intensity ε acting on the frequency, and the curve of different coal gangue contents, and it is obtained:

[0054]

[0055] Where L1 is the lumped inductor, C1 is the capacitance of the parallel plate capacitor, and C n (the subscripts correspond to the serial numbers in Table 1) represent the varying capacitance caused by different contents of gangue;

[0056] And from the above formula, we can know the following linear relationship:

[0057] ε~|f n -f0|~C n

[0058] Where ε represents the perturbation intensity, |f n -f0|Frequency offset, C n Indicates the changing capacitance caused by different contents of coal gangue.

[0059] By synthesizing the lumped inductance L1, lumped inductance L2, lumped inductance L3, bypass capacitor C0, lumped capacitor C1 and lumped capacitor C2 in the third-order PT symmetric circuit, according to KVL, we can get

[0060]

[0061] Where Z1=iωL1+1 / (iωC1), Z2=iωL2+1 / (iωC2), Z3=iωL3+1 / (iωC3);

[0062] Among them, L1 represents the lumped inductance L1, the lumped inductance L2 and the lumped capacitance C1, and the lumped inductance L3.

[0063] According to the symmetry of the structure: L1 = L, C1 = C3, C2 = CC 00 / (C 00 -2C), C 00 =C 01 , R1=R, using the approximate condition The simplified equation is:

[0064]

[0065] in The coupling strengths are γ = R / (2L) and κ = ω0C / (2C 00 ).

[0066] Solving the equation, we can get the eigenfrequency as:

[0067] ω1=ω0,

[0068] The ideal third-order PT symmetry is obtained through the above equations, when κ and γ satisfy the critical relationship When , the three eigenfrequencies are combined at ω0, and the circuit works in the EP3 state.

[0069] Example 2: Recent advances in the field of non-Hermitian physics and parity time symmetry (PT) have shown that in optics and photonics near the PT phase transition point (EP point), eigenvalues ​​and eigenvectors merge simultaneously, thereby achieving enhanced sensitivity. EP points are a prominent feature of non-Hermitian systems that exchange energy with the environment. They appear in gain- and loss-controlled systems and exhibit a greatly amplified response to small perturbations. They can be used to design resonant sensors with greatly improved sensitivity. In addition, at the third-order EP point of the optical resonator, square root behavior of the eigenfrequency splitting that depends on the external perturbation has been experimentally observed. Similarly, for wireless LC sensors, when the change to be measured acts on the third-order EP point, the resonant frequency offset of the system should also change with the square root of the change to be measured.

[0070] This embodiment firstly realizes the condition of satisfying the third-order EP point through the theoretical model of the third-order PT symmetric integrated system, and then studies the wireless sensor system for monitoring the coal-gangue mixing ratio based on the third-order EP point proposed in this embodiment.

[0071] Circuit model theory of third-order PT symmetric system:

[0072] The circuit diagram of the third-order PT symmetric system in this embodiment is as follows Figure 2 As shown, the circuit is composed of a lumped resonant unit (lumped inductor L1 and lumped capacitor C1, lumped inductor L3 and parallel plate capacitor C3), a distributed resonant unit (lumped inductor L2 and lumped capacitor C2) and two bypass capacitors (lumped capacitor C0).

[0073] like Figure 2 The circuit shown in the figure can be obtained according to KVL.

[0074]

[0075] Here Z1=iωL1+1 / (iωC1), Z2=iωL2+1 / (iωC2), Z3=iωL3+1 / (iωC3). Considering the symmetry of the structure: L1=L, C1=C3, C2=CC 00 / (C 00 -2C), C 00 =C 01 , R1=R, using the approximate condition Equation (1.1) can be simplified to

[0076]

[0077] in The coupling strengths are γ = R / (2L) and κ = ω0C / (2C 00 ), solving equation (1.2) yields the eigenfrequency

[0078]

[0079] Equation (1.3) indicates that the system realizes the ideal third-order PT symmetry. When κ and γ satisfy the critical relationship When , the three eigenfrequencies are combined at ω0, and the system works in the EP3 state.

[0080] Moreover, the latest progress of non-Hermitian physics in the field of optics and photonics shows that near the singularity, when an external perturbation ε is applied to n degenerate eigenmodes (i.e., EPn), the relationship between the system's eigenfrequency and the perturbation ε follows the nth-root law, i.e., Δω~ε 1 / n .Right now

[0081] Re(ω)~ε 1 / 3 . (1.4)

[0082] This formula shows that the resonant frequency shift of the third-order PT symmetric system near EP has a 1 / 3 power relationship with the external disturbance, which has a higher amplification factor than the 1 / 2 power dependence of the second-order PT symmetry.

[0083] Passive wireless sensing system for monitoring coal-gangue mixing ratio based on third-order EP point:

[0084] The structural diagram of the wireless sensor system for monitoring the coal-gangue mixing ratio based on the third-order EP point proposed in this embodiment is as follows: Figure 1 As shown, including detailed information of each component; lumped inductor L1, lumped inductor L2 and lumped inductor L3 are annular FeSiAl inductors (model S106125) with a current resistance of 10A, where the pins at both ends of the inductor are 1mm. The bypass capacitor C0, lumped capacitor C1 and lumped capacitor C2 are metallized polyester film plug-in lumped capacitors with a voltage resistance of 250V. The parallel plate capacitor C3 is composed of two aluminum plates with a thickness of 1mm, a length of 40mm and a width of 30mm, and the interval between the two aluminum plates is 40mm. All components except the parallel plate capacitor are integrated on the PCB board, which can save the space occupied by the system. Considering the symmetry of the electrical parameters, the parameters of the inductor and capacitor are set as follows: L1=L2=L3=L≈0.73mH. When C0 changes, the adjustment of C1 always satisfies the relationship C1=CC0 / (C0-C), and the adjustment of C2 always satisfies the relationship C2=CC0 / (C0-2C), where C≈4.76nF is a constant.

[0085] In this embodiment, Port 1 of the vector network analyzer VNA is used as an AC source, one end of the lumped inductor L1 away from the bypass capacitor C0 and one end of the lumped capacitor C1 away from the bypass capacitor C0 are connected in series with the AC source, and one end of the lumped inductor L3 away from the bypass capacitor C0 and one end of the parallel plate capacitor C3 away from the bypass capacitor C0 are connected in series with Port 2 of the vector network analyzer (as a load); the first end of a bypass capacitor C0 is connected between the lumped capacitor C1 and the lumped inductor L1, and the second end is connected between the lumped capacitor C2 and the lumped inductor L2, and the first end of another bypass capacitor C0 is connected between the lumped capacitor C2 and the lumped inductor L2, and the second end is connected between the plate capacitor C3 and the lumped inductor L3. The two plates of the parallel plate capacitor are used to place mixed samples of coal gangue in different proportions. The content of coal gangue in mixed samples of coal gangue in different proportions is shown in Table 1:

[0086] Table 1

[0087]

[0088] In this embodiment, the influence of different proportions of coal gangue mixed samples on a single resonant coil wireless sensor system is first studied. The system is stabilized at the resonant frequency, and the reflectance spectra of the passive wireless sensor system at different coal gangue mixing ratios are measured as shown in Figure 3(a). The resonant frequencies f n and frequency offset |f n The curves of -f0| (perturbation intensity ε acting on frequency) with different coal gangue contents are shown in Figure 3(b) and Figure 3(c), and it is concluded that:

[0089]

[0090] Where L1 is the lumped inductor, C1 is the capacitance of the parallel plate capacitor, and C n (The subscripts correspond to the serial numbers in Table 1) represent the changing capacitance caused by different contents of coal gangue.

[0091] And from the above formula, we can know the next-order linear relationship:

[0092] ε~|f n -f0|~C n (1.6)

[0093] Then, the measured perturbation intensity is used to analyze the third-order PT symmetric wireless sensor system, and the measured reflection spectrum is shown in Figure 4(a). Figure 4(b) is the frequency offset |f extracted from Figure 4(a). n ′-f0′| and the theoretical ε calculated by formula (9) 1 / 3 The comparison diagram of the curves shows that the two are in good agreement. By taking logarithmic coordinates for Figure 4(b), we can obtain the result shown in Figure 4(c), from which we can obtain the curve (y = ε 1 / 3 )The conclusion of the same slope 1 / 3.

[0094] In addition, this embodiment also uses the same method to analyze the second-order PT symmetric wireless sensor system, and its structural diagram is shown in FIG. Figure 5As shown, the lumped inductor L1 and the lumped inductor L2 are annular FeSiAl inductors (model S106125) with a current resistance of 10A, where the pins at both ends of the inductor are 1mm. The parallel plate capacitor C1 is composed of two aluminum plates with a thickness of 1mm, a length of 40mm, and a width of 30mm, and the interval between the two aluminum plates is 40mm. The bypass capacitor C0 and the lumped capacitor C2 are metallized polyester film plug-in lumped capacitors with a high voltage resistance of more than 630V. All components except the parallel plate capacitor are integrated on the PCB board, which can save the space occupied by the system. Considering the symmetry of the electrical parameters, the parameters of the inductor and capacitor are set as follows: L1 = L2 = L≈0.87mH. When C0 changes, the adjustment of C2 always satisfies the relationship C2 = CC0 / (C0-C), where C≈4.76nF is a constant.

[0095] It can be seen from Figure 6(a) to Figure 6(c) that the resonant frequency offset |f n ′-f0′| and the perturbation intensity ε have a 1 / 2 order relationship.

[0096] Example 3: This example also analyzes the sensitivity enhancement factor |f of the second-order PT symmetric wireless sensor system and the third-order PT symmetric wireless sensor system. n ′-f0′| / ε, the result is as follows Figure 7 As shown, since the perturbation intensity comes from the change of gangue content, and the two are in a first-order linear relationship, the horizontal axis is taken as gangue content. It can be seen that the sensitivity enhancement factor decreases with the increase of gangue content, and the sensitivity enhancement factors corresponding to the two different systems are also different. When the gangue content of the measured samples is 6.25%, 25% and 31.25%, the sensitivity enhancement factor of the third-order PT symmetric system is increased by 77.8%, 51.9% and 41.5% respectively compared with the second-order PT symmetric system. Therefore, the third-order PT symmetric wireless sensing system proposed in this embodiment has more advantages in monitoring the mixing ratio of gangue.

[0097] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. Although the present invention has been described in detail with reference to the above embodiments, the present invention is not limited to the above specific implementation methods. Therefore, any modification or equivalent replacement of the present invention; and all technical solutions and improvements thereof that do not depart from the spirit and scope of the invention are included in the scope of the claims of the present invention.

Claims

1. An integrated third-order PT symmetric high-sensitivity wireless sensor circuit device, characterized in that: It includes a lumped resonant unit, a distributed resonant unit and two bypass capacitors. The lumped resonant unit includes a lumped inductor L1 and a lumped capacitor C1, a lumped inductor L3 and a parallel plate capacitor C3. The distributed resonant unit includes a lumped inductor L2 and a lumped capacitor C2. The bypass capacitor includes a lumped capacitor C0.

2. The integrated third-order PT symmetric high-sensitivity wireless sensor circuit device according to claim 1 is characterized in that: Including detailed information of its various components; the lumped inductor L1, the lumped inductor L2 and the lumped inductor L3 are annular FeSiAl inductors with a current resistance of 10A, and the pins at both ends of the inductor are 1mm; the bypass capacitor C0, the lumped capacitor C1 and the lumped capacitor C2 are metallized polyester film direct-insertion lumped capacitors with a voltage resistance of 250V.

3. The integrated third-order PT symmetric high-sensitivity wireless sensor circuit device according to claim 2 is characterized in that: It also includes a parallel plate capacitor C3, which is composed of two aluminum plates with a thickness of 1 mm, a length of 40 mm, and a width of 30 mm, and the interval between the two aluminum plates is 40 mm; except for the parallel plate capacitor, other components are integrated on the PCB board.

4. The integrated three-order PT symmetric high-sensitivity wireless sensor circuit device according to claim 3 is characterized in that: The parameters of the inductor and capacitor are set as follows: L1=L2=L3=L≈0.73mH; When C0 changes, the adjustment of C1 always satisfies the relationship C1=CC0 / (C0-C), and the adjustment of C2 always satisfies the relationship C2=CC0 / (C0-2C), where C≈4.76nF is a constant.

5. The integrated three-order PT symmetric high-sensitivity wireless sensor circuit device according to claim 4 is characterized in that: Port 1 of the vector network analyzer VNA is used as an AC source, one end of the lumped inductor L1 away from the bypass capacitor C0 and one end of the lumped capacitor C1 away from the bypass capacitor C0 are connected in series with the AC source, and one end of the lumped inductor L3 away from the bypass capacitor C0 and one end of the parallel plate capacitor C3 away from the bypass capacitor C0 are connected in series with Port 2 of the vector network analyzer.

6. The integrated three-order PT symmetric high-sensitivity wireless sensor circuit device according to claim 5, characterized in that: Port 2 of the vector network analyzer is used as a load; a first end of a bypass capacitor C0 is connected between the lumped capacitor C1 and the lumped inductor L1, and a second end is connected between the lumped capacitor C2 and the lumped inductor L2; a first end of another bypass capacitor C0 is connected between the lumped capacitor C2 and the lumped inductor L2, and a second end is connected between the flat plate capacitor C3 and the lumped inductor L3; and mixed samples of coal gangue in different proportions are placed between the two plates of the parallel plate capacitor.

7. The integrated three-order PT symmetric high-sensitivity wireless sensor circuit device according to claim 6, characterized in that: Through the influence of different proportions of coal gangue mixed samples on a single resonant coil system, the system is stabilized at the resonant frequency, the reflection spectrum of the passive wireless sensor system under different coal gangue mixing ratios is measured, and the resonant frequency f is extracted respectively. n and frequency offset |f n -f0|, the perturbation intensity ε acting on the frequency, and the curve of different coal gangue contents, and it is obtained: Where L1 is the lumped inductor, C1 is the capacitance of the parallel plate capacitor, and C n (the subscripts correspond to the serial numbers in Table 1) represent the varying capacitance caused by different contents of gangue; And from the above formula, we can know the following linear relationship: ε~|f n -f0|~C n Where ε represents the perturbation intensity, |f n -f0|Frequency offset, C n Indicates the changing capacitance caused by different contents of coal gangue.

8. The integrated three-order PT symmetric high-sensitivity wireless sensor circuit device according to claim 7, characterized in that: By synthesizing the lumped inductance L1, lumped inductance L2, lumped inductance L3, bypass capacitor C0, lumped capacitor C1 and lumped capacitor C2 in the third-order PT symmetric circuit, according to KVL, we can get Where Z1=iωL1+1 / (iωC1), Z2=iωL2+1 / (iωC2), Z3=iωL3+1 / (iωC3); Among them, L1 represents the lumped inductance L1, the lumped inductance L2 and the lumped capacitance C1, and the lumped inductance L3.

9. The integrated three-order PT symmetric high-sensitivity wireless sensor circuit device according to claim 8, characterized in that: According to the symmetry of the structure: L1 = L, C1 = C3, C2 = CC 00 / (C 00 -2C), C 00 =C 01 , R1=R, using the approximate condition The simplified equation is: in The coupling strengths are γ = R / (2L) and κ = ω0C / (2C 00 ).

10. The integrated three-order PT symmetric high-sensitivity wireless sensor circuit device according to claim 9, characterized in that: Solving the equation, we can get the eigenfrequency as: The ideal third-order PT symmetry is obtained through the above equations, when κ and γ satisfy the critical relationship When , the three eigenfrequencies are combined at ω0, and the circuit works in the EP3 state; Near the singular point, when the external disturbance ε is applied to n degenerate eigenmodes (i.e., EPn), the relationship between the system eigenfrequency and the disturbance ε follows the nth root law, i.e., Δω~ε 1 / n ;Right now Re(ω)~e 13 . This equation shows that the resonant frequency shift of the third-order PT symmetric system near EP has a 1 / 3 power relationship with the external disturbance.

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