A microwave sensor for traditional Chinese medicine reagent detection

Abstract

The application discloses a microwave sensor for traditional Chinese medicine reagent detection, and relates to the technical field of sensors, which comprises a dielectric plate, the top surface of the dielectric plate is provided with a radiation layer, the bottom surface of the dielectric plate is provided with a grounding layer, the radiation layer is etched with a radiation unit, and the left and right sides of the radiation layer are provided with microstrip lines; the radiation unit comprises a radiation ring groove, the left and right sides in the radiation ring groove are provided with symmetrical gathering modules, the gathering modules are communicated with the radiation ring groove and are used for prolonging a current transmission path; the middle part of the radiation ring groove is provided with an open ring capacitor arm module, and the two ends of the open ring capacitor arm module are respectively communicated with the radiation ring groove through connecting line grooves. The electromagnetic energy can be maximally gathered in a target detection area by adopting the application, so that the electromagnetic wave radiation intensity is improved, and the detection sensitivity is improved.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and in particular to a microwave sensor for detecting traditional Chinese medicine reagents. Background Technology

[0002] Currently, traditional methods for detecting heavy metal content in traditional Chinese medicine decoctions mainly include atomic absorption spectrometry, atomic fluorescence spectrometry, and inductively coupled plasma mass spectrometry. However, although these methods offer high accuracy, they generally suffer from problems such as complex operation, long detection time, expensive equipment, and cumbersome sample pretreatment, making it difficult to meet the needs for rapid, convenient, and on-site detection. Furthermore, due to the complex composition and sample condition of traditional Chinese medicine decoctions, traditional detection methods may face issues such as insufficient detection sensitivity and numerous heavy metal interference factors in practical applications, limiting their widespread use.

[0003] In recent years, with the rapid development of sensor technology, microwave sensors have gradually become an emerging technology in the field of heavy metal detection due to their advantages such as high sensitivity and fast response. Microwave sensors analyze the heavy metal content in samples by detecting the absorption, reflection, or scattering characteristics of microwave signals. They offer advantages such as ease of operation, rapid response, and high detection sensitivity, making them particularly suitable for rapid on-site detection. However, the application of existing microwave sensors in complex systems of traditional Chinese medicine decoctions still faces many technical challenges, such as insufficient detection sensitivity. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a microwave sensor for the detection of traditional Chinese medicine reagents, which can maximize the concentration of electromagnetic energy in the target detection area to improve the intensity of electromagnetic radiation and thus improve the detection sensitivity.

[0005] By employing a dual-resonant structure coupled with a microstrip line using complementary open-cell resonant units, a dual-resonant transmission response can be excited, thereby improving the detection accuracy and sensitivity of the sensor.

[0006] To address the aforementioned technical problems, this invention provides a microwave sensor for detecting traditional Chinese medicine reagents, comprising a dielectric substrate, a radiating layer on the top surface of the dielectric substrate, a grounding layer on the bottom surface of the dielectric substrate, radiating units etched in the radiating layer, and microstrip lines on the left and right sides of the radiating layer; each radiating unit includes a radiating annular groove, and symmetrically arranged convergent modules on the left and right sides of the radiating annular groove, the convergent modules being connected to the radiating annular groove to extend the current transmission path; an open-ring capacitor arm module is provided in the middle of the radiating annular groove, and both ends of the open-ring capacitor arm module are connected to the radiating annular groove via connecting wire grooves.

[0007] As an improvement to the above solution, the gathering module includes a spiral channel, the starting end of which is connected to the radiation ring channel, and the ending end of which is located in the middle; a wire groove is provided between the starting end and the ending end, and the wire groove is spirally arranged around the ending end from the outside to the inside.

[0008] As an improvement to the above solution, the open-ring capacitor arm module includes an upper open-ring capacitor arm and a lower open-ring capacitor arm. An open-ring groove and a coupling capacitor arm are formed between the upper open-ring capacitor arm and the lower open-ring capacitor arm. The coupling capacitor arm is located in the open-ring groove, and an opening structure is formed on both sides of the open-ring groove.

[0009] As an improvement to the above scheme, the upper and lower sides of the radiation layer are respectively provided with a plurality of vias and metal cylinders arranged at intervals. The metal cylinders are inserted through the vias into the dielectric substrate and the ground layer, and the metal cylinders are respectively connected to the radiation layer and the ground layer; the radiation unit is located between the metal cylinders on the upper and lower sides.

[0010] As an improvement to the above solution, the upper open-ring capacitor arm includes an upper half-ring groove and an upper capacitor arm connected to the upper half-ring groove, the middle part of the upper half-ring groove being connected to the radial ring groove via the connecting wire groove; the lower open-ring capacitor arm includes a lower half-ring groove and a lower capacitor arm connected to the lower half-ring groove, the middle part of the lower half-ring groove being connected to the radial ring groove via the connecting wire groove; the upper half-ring groove and the lower half-ring groove are spaced apart, and the two together form the open-ring groove; the upper capacitor arm and the lower capacitor arm have a center-point symmetrical structure, and the two together form the coupling capacitor arm.

[0011] As an improvement to the above scheme, the upper capacitor arm is an inverted F-shaped capacitor arm, and the lower capacitor arm is an F-shaped capacitor arm; both the inverted F-shaped capacitor arm and the F-shaped capacitor arm include a main arm, and the main arm is provided with two branch arms arranged perpendicularly to it, and the branch arms of the inverted F-shaped capacitor arm are located below the branch arms of the F-shaped capacitor arm.

[0012] As an improvement to the above scheme, the ratio of the length F2 of the branch arm to the length F1 of the main arm is E=F2 / F1, and the value of E is in the range of 0.81<E<0.92.

[0013] As an improvement to the above scheme, the length F1 of the main arm is 0.73mm~0.77mm, the length F2 of the branch arm is 0.63mm~0.67mm, and the width FS of both the main arm and the branch arm is 0.05mm~0.09mm.

[0014] As an improvement to the above solution, the spiral groove is rectangular, circular, or elliptical in shape.

[0015] As an improvement to the above solution, the microstrip line is a trapezoidal microstrip line, one end of which is connected to the SMA connector, and the SMA connector is connected to an external network analyzer or integrated microwave module.

[0016] The beneficial effects of implementing this invention are as follows:

[0017] This invention extends the current transmission path of the radiation unit through the radiation ring groove and the focusing module. When a portion of the current flows through the structural path of the radiation ring groove and the focusing module, a magnetic field is formed and acts on the open-ring capacitor arm module. At the same time, when another portion of the current flows to the open-ring capacitor arm module, an open-ring capacitor is formed, which interacts with the equivalent inductance of the radiation ring groove and the focusing module to achieve a resonant function. This causes the circuit of the radiation unit to resonate and store electromagnetic energy, thereby concentrating the electromagnetic energy above the radiation unit and above the middle of the radiation layer. In other words, the electromagnetic energy is maximized in the target detection area, which can improve the intensity of electromagnetic wave radiation and thus improve the detection sensitivity of the microwave sensor. It is suitable for high-precision detection of heavy metal content in liquid samples. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the top structure of the microwave sensor used for detecting traditional Chinese medicine reagents according to the present invention;

[0019] Figure 2 This is a schematic diagram of the bottom structure of the microwave sensor of the present invention;

[0020] Figure 3 This is a schematic diagram of the structure of the open-ring capacitor arm module of the present invention;

[0021] Figure 4 This is a schematic diagram of the dimensions of the microwave sensor of the present invention;

[0022] Figure 5 This is a schematic diagram of the dimensions of the open-ring capacitor arm module of the present invention;

[0023] Figure 6 The S of the microwave sensor under different dielectric constants in Embodiment 1 of the present invention 21 A curve showing the frequency deviation at the resonant point;

[0024] Figure 7 This refers to the S-type microwave sensor under different thicknesses of the object being measured in Embodiment 1 of the present invention. 21 A curve showing the frequency deviation at the resonant point;

[0025] Figure 8 The S of the microwave sensor under different dielectric constants in Embodiment 2 of the present invention 21 A curve showing the frequency deviation at the resonant point;

[0026] Figure 9 This is the S of the microwave sensor under different dielectric constants in Comparative Example 1 of the present invention. 21 A curve showing the frequency deviation at the resonant point;

[0027] Figure 10 The S of microwave sensors under different dielectric constants in Comparative Example 2 of this invention 21 A curve showing the frequency deviation at the resonant point. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the invention, and should not be construed as limiting the invention. Furthermore, it should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0029] In this document, references to "embodiment" or "implementation" mean that a particular feature, component, or characteristic described in connection with an embodiment or implementation may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0030] like Figures 1 to 2 As shown in the figure, a specific embodiment of the present invention provides a microwave sensor for detecting traditional Chinese medicine reagents, including a dielectric substrate 1, a copper-clad radiation layer 11 on the top surface of the dielectric substrate 1, a copper-clad ground layer 12 on the bottom surface of the dielectric substrate 1, microstrip lines 13 on the left and right sides of the radiation layer 11, one end of the microstrip line 13 being connected to the SMA connector, and the SMA connector being connected to an external network analyzer or integrated microwave module.

[0031] Radiation units 2 are etched in the radiation layer 11, that is, the radiation units 2 with notches are etched into the radiation layer 11. The radiation units 2 include radiation ring grooves 3. Symmetrical gathering modules 4 are provided on the left and right sides of the radiation ring grooves 3. The gathering modules 4 on both sides are connected to the radiation ring grooves 3 to extend the current transmission path of the radiation units 2, so as to generate more electromagnetic energy above the radiation units 2 and concentrate the electromagnetic energy above the radiation units 2. An open ring capacitor arm module 5 is provided in the middle of the radiation ring groove 3. The two ends of the open ring capacitor arm module 5 are connected to the radiation ring groove 3 through connecting wire grooves 14 respectively.

[0032] When current is fed into the radiation layer 11 through the microstrip line 13, a portion of the current flows through the radiation ring groove 3 to the current transmission path of the focusing module 4 and forms a magnetic field that acts on the open-ring capacitor arm module 5. The focusing module 4 extends the current transmission path, thereby generating more electromagnetic energy and concentrating it above the radiation ring groove 3. At the same time, another portion of the current flows through the connecting groove 14 to the open-ring capacitor arm module 5, forming an open-ring capacitor. This open-ring capacitor interacts with the equivalent inductance of the radiation ring groove 3 and the focusing module 4 to achieve a resonant function, so that the circuit of the radiation unit 2 resonates and stores electromagnetic energy. This concentrates the electromagnetic energy above the radiation unit 2 and above the middle part of the radiation layer 11, that is, the electromagnetic energy is maximized in the target detection area, which can improve the electromagnetic wave radiation intensity and thus improve the detection sensitivity of the microwave sensor.

[0033] When detecting heavy metals in traditional Chinese medicine decoctions and complex liquids, changes in the concentration of heavy metal ions in the liquid cause alterations in the polarization and conductivity of the medium, resulting in a measurable shift in the sensor's resonant frequency and amplitude. By establishing a calibration relationship between frequency change and heavy metal concentration, quantitative or semi-quantitative detection of ions such as lead, cadmium, mercury, and copper can be achieved. Therefore, when using the microwave sensor of this invention to detect a liquid sample placed above the radiation layer 11, a network analyzer or integrated microwave module can be used to perform frequency sweeping processing on the microwave sensor to quickly and accurately obtain the resonant changes caused by heavy metal ions in the liquid sample. Based on these resonant changes, the content of heavy metal ions in the liquid sample can be accurately determined, thus achieving high-precision detection of heavy metal content in liquid samples. This is suitable for rapid screening in pharmaceutical production sites or distribution channels.

[0034] Specifically, the focusing module 4 includes a spiral through-slot 41, the starting end 411 of which is connected to the radiation ring groove 3, and the ending end 412 of which is located in the middle. A wire groove 413 is provided between the starting end 411 and the ending end 412, and the wire groove 413 is spirally arranged around the ending end 412 from the outside to the inside to form a spiral circuit transmission path. Under the same volume, the spiral through-slot 41 can maximize the extension of the circuit transmission path of the radiation ring groove 3 to reduce the local current density, so that the spiral through-slot 41 can uniformly disperse electromagnetic waves and increase the electric field strength between the spiral through-slots 41, thereby increasing the electromagnetic energy above the radiation unit 2.

[0035] Preferably, the spiral groove 41 is rectangular spiral in shape, but this is not a limitation. The spiral groove 41 can also be set to a circular spiral or an elliptical spiral according to actual needs.

[0036] To improve the electromagnetic energy focusing effect above radiation unit 2, such as Figures 1 to 2 As shown, the upper and lower sides of the radiating layer 11 are respectively provided with a plurality of vias 15 and metal cylinders 16 arranged at intervals. The metal cylinders 16 are inserted into the dielectric substrate 1 and the ground layer 12 through the vias 15, so that the metal cylinders 16 are connected to the radiating layer 11 and the ground layer 12 respectively. The radiating unit 2 is located between the upper and lower metal cylinders 16 to surround the radiating unit 2. The plurality of metal cylinders 16 arranged in this surrounding manner can concentrate the electromagnetic wave energy radiated by the radiating unit 2 above the radiating unit 2 or above the middle of the radiating layer 11, so as to reduce the leakage of electromagnetic wave energy, thereby increasing the electromagnetic wave radiation intensity and thus improving the detection sensitivity of the microwave sensor.

[0037] Furthermore, such as Figure 1 , 3 As shown in Figure 5, the open-ring capacitor arm module 5 includes an upper open-ring capacitor arm 51 and a lower open-ring capacitor arm 52. An open-ring groove and a coupling capacitor arm are formed between the upper open-ring capacitor arm 51 and the lower open-ring capacitor arm 52. The coupling capacitor arm is located in the open-ring groove. Opening structures 53 are formed on both sides of the open-ring groove, which are the openings of the radiation ring groove 3, forming an open-ring capacitor. This open-ring capacitor interacts with the radiation ring groove 3 and the equivalent inductance of the focusing module 4 to achieve a resonant function, causing the circuit of the radiation unit 2 to resonate and store electromagnetic energy. This concentrates the electromagnetic energy above the radiation unit 2 and above the middle of the radiation layer 11, increasing the electromagnetic wave radiation intensity and thus improving the detection sensitivity. The coupling capacitor arm is placed in the open-ring groove to increase the coupling strength of the open-ring capacitor arm module 5, thereby enhancing energy transmission efficiency and optimizing the electromagnetic field distribution, ultimately improving the electromagnetic wave radiation effect.

[0038] The upper open-ring capacitor arm 51 includes an upper half-ring groove 511 and an upper capacitor arm 512 connected to the upper half-ring groove 511. The middle part of the upper half-ring groove 511 is connected to the radial ring groove 3 via the connecting wire groove 14. The lower open-ring capacitor arm 52 includes a lower half-ring groove 521 and a lower capacitor arm 522 connected to the lower half-ring groove 521. The middle part of the lower half-ring groove 521 is connected to the radial ring groove 3 via the connecting wire groove 14. The upper half-ring groove 511 and the lower half-ring groove 521 are spaced apart and together form the open-ring groove. The upper capacitor arm 512 and the lower capacitor arm 522 have a center-point symmetrical structure and together form the coupling capacitor arm.

[0039] The upper capacitor arm 512 is an inverted F-shaped capacitor arm, and the lower capacitor arm 522 is an F-shaped capacitor arm. Both the inverted F-shaped capacitor arm and the F-shaped capacitor arm include a main arm 6. The main arm 6 is provided with two branch arms 7 arranged perpendicularly to it. The branch arms 7 of the inverted F-shaped capacitor arm are located below the branch arms 7 of the F-shaped capacitor arm.

[0040] It should be noted that the present invention can stabilize electromagnetic radiation energy and reduce lateral energy leakage through the structure of the upper and lower semi-annular grooves (511, 521) of the open-ring capacitor arm module 5, thereby further concentrating electromagnetic energy at the radiation center and improving detection sensitivity. In addition, the upper capacitor arm 512 and the lower capacitor arm 522 of the present invention have a double F-shaped structure, which can transmit energy through the main arm 6 in the F-shaped capacitor arm, and multiple branch arms 7 are used to distribute the transmitted energy. In this way, the coupling strength of electromagnetic waves at the radiation center can be improved.

[0041] Furthermore, the ratio of the length F2 of the branch arm 7 to the length F1 of the main arm 6 is E = F2 / F1, and the value of E is in the range of 0.81 < E < 0.92.

[0042] For example, the ratio E of the length F2 of the branch arm 7 to the length F1 of the main arm 6 is 0.820, 0.830, 0.840, 0.850, 0.860, 0.870, 0.880, 0.890, 0.900, 0.910, and 0.917, but is not limited to these values. Within this range, the two capacitor arms in the open-ring capacitor arm module 5 can achieve better coupling and higher coupling strength, thereby more effectively exciting the electromagnetic field to focus radiation at the center, improving the electromagnetic wave radiation effect above the radiation unit 2 and above the middle of the radiation layer 11 (i.e., the detection area), and thus improving the sensitivity of detecting the heavy metal content of the test solution sample located in the detection area. If the ratio E is lower than this range, the coupling strength between the two capacitor arms in the open-ring capacitor arm module 5 is weak, and it cannot effectively excite the electromagnetic field to focus and radiate at the center; if the ratio E is higher than this range, the length distance between the two capacitor arms in the open-ring capacitor arm module 5 is too close, which will cause electromagnetic interference, affect electromagnetic wave radiation, and reduce detection sensitivity.

[0043] In this embodiment of the invention, the length F1 of the main arm 6 is 0.73mm~0.77mm, the length F2 of the branch arm 7 is 0.63mm~0.67mm, and the width FS of both the main arm 6 and the branch arm 7 is 0.05mm~0.09mm. Within this range, the overall volume of the open ring capacitor arm module 5 is small, while also achieving stronger coupling strength between capacitor arms and better battery wave focusing radiation effect, resulting in excellent overall performance.

[0044] Preferably, such as Figure 1 As shown, the microstrip line 13 is a trapezoidal microstrip line. By optimizing impedance continuity through a gradually changing linewidth, the port reflection coefficient can be reduced, signal reflection and loss can be reduced, and high-frequency signal integrity can be improved. Moreover, impedance matching can be achieved by adjusting the linewidth gradient, reducing signal reflection and discontinuity.

[0045] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0046] Example 1

[0047] like Figures 1 to 5 As shown, the present invention provides a microwave sensor, including a dielectric substrate 1, a radiating layer 11 on the top surface of the dielectric substrate 1, a grounding layer 12 on the bottom surface of the dielectric substrate 1, radiating units 2 etched in the radiating layer 11, and microstrip lines 13 on the left and right sides of the radiating layer 11; the radiating unit 2 includes a radiating annular groove 3, and symmetrically arranged convergent modules 4 on the left and right sides of the radiating annular groove 3, the convergent modules 4 being connected to the radiating annular groove 3 to extend the current transmission path; an open-ring capacitor arm module 5 is provided in the middle of the radiating annular groove 3, and the two ends of the open-ring capacitor arm module 5 are respectively connected to the radiating annular groove 3 via connecting wire grooves 14.

[0048] The open-ring capacitor arm module 5 includes an upper open-ring capacitor arm 51 and a lower open-ring capacitor arm 52. An open-ring groove and a coupling capacitor arm are formed between the upper open-ring capacitor arm 51 and the lower open-ring capacitor arm 52. The coupling capacitor arm is located in the open-ring groove. An opening structure 53 is formed on both sides of the open-ring groove. The upper open-ring capacitor arm 51 includes an upper semi-ring groove 511 and an upper capacitor arm 512 connected to the upper semi-ring groove 511. The middle part of the upper semi-ring groove 511 is connected to the radial ring groove 3 via the connecting wire groove 14. The lower open-ring capacitor arm 52 includes a lower semi-ring groove 521 and a lower capacitor arm 522 connected to the lower semi-ring groove 521. The middle part of the lower semi-ring groove 521 is connected to the radial ring groove 3 via the connecting wire groove 14. The upper semi-ring groove 511 and the lower semi-ring groove 521 are spaced apart and together form the open-ring groove. The upper capacitor arm 512 and the lower capacitor arm 522 have a center-point symmetrical structure and together form the coupling capacitor arm.

[0049] The upper capacitor arm 512 is an inverted F-shaped capacitor arm, and the lower capacitor arm 522 is an F-shaped capacitor arm. Both the inverted F-shaped capacitor arm and the F-shaped capacitor arm include a main arm 6. The main arm 6 is provided with two branch arms 7 arranged perpendicularly to it. The branch arms 7 of the inverted F-shaped capacitor arm are located below the branch arms 7 of the F-shaped capacitor arm.

[0050] In this embodiment, the length of the dielectric substrate 1 is L_sub, which is 20 mm; the width of the wave sensor is W_sub, which is 16 mm; the length of the radiation ring groove 3 is L, which is 10 mm; the width of the radiation ring groove 3 is W, which is 8.2 mm; the groove width W1 of the radiation ring groove 3 is 0.14 mm; the length of the focusing module 4 is QL, which is 4.35 mm; the width of the focusing module 4 is QW, which is 3.3 mm; the groove width QW1 of the spiral through groove 41 of the focusing module 4 is 0.27 mm; the outer ring radius R of the upper half-ring groove 511 and the lower half-ring groove 521 is 0.63 mm; the length F1 of the main arm 6 is 0.75 mm; the length F2 of the branch arm 7 is 0.65 mm; and the width FS of the main arm 6 and the branch arm 7 is 0.088 mm. The ratio E of the length F2 of the branch arm 7 to the length F1 of the main arm 6 is approximately 0.87. Furthermore, the operating frequency of the microwave sensor is 4 GHz.

[0051] It should be noted that a rectangular dielectric plate 1, used to simulate the variable dielectric constant of the test reagent, is placed on the radiating layer 11, with the rectangular dielectric plate 1 facing the radiating element 2. By using rectangular dielectric layers with different dielectric constants, the microwave sensor of this embodiment is tested to obtain results such as... Figure 6 The S values ​​of microwave sensors with different dielectric constants are shown. 21 (Transmission parameters) Resonant point frequency deviation curve. As shown in the graph, as the dielectric constant of the test reagent changes from 1 to 5, S... 21 The resonant point exhibits a significant frequency shift and gradually moves towards lower frequencies. This is because when the test reagent is placed in the measurement area, the microwave sensor is affected by factors such as the dielectric constant and permeability of the test reagent, resulting in field effect disturbances and causing changes in the resonant point frequency.

[0052] Next, to further verify the effect of the test reagent content on the performance of the microwave sensor, this embodiment tested rectangular dielectric plates 1 with the same dielectric constant and different thicknesses, obtaining the following results: Figure 7 The microwave sensor S is shown under different thicknesses of the object being measured. 21 The graph shows the frequency offset at the resonant point. As can be seen from the graph, the change in the thickness of the object under test from 0.4 mm to 1.2 mm affects the S-frequency offset of the microwave sensor. 21 The resonant point did not change significantly, remaining around 3.5 GHz, indicating that the content of the test reagent did not significantly affect the sensor sensitivity. Finally, the experimental results show that the microwave sensor is mainly affected by factors such as the dielectric constant and permeability of the test reagent. Figure 6 S with dielectric constants from 1 to 5 21 The lowest point can be determined from the curve. Based on this lowest point, the resonant point of the microwave sensor under load can be obtained. Then, the sensitivity of the local wave sensor for detecting analytes with different dielectric constants can be calculated using the sensitivity calculation formula, which is as follows:

[0053]

[0054] Among them, S ε f represents the sensitivity of the microwave sensor. ε f is the resonant frequency of the microwave sensor when it is loaded (i.e., the resonant frequency of the resonant point). unload ε is the no-load resonant frequency of the microwave sensor when it is unloaded, and ε is the value of the dielectric constant of the object under test.

[0055] The sensitivity of the microwave sensor under different dielectric constants (e.g., dielectric constants 1 to 5) can be calculated using the above sensitivity calculation formula. Then, the average of multiple sensitivity values ​​is calculated to obtain the final sensitivity data of the microwave sensor, which is 22.3%, far exceeding the sensitivity of existing microwave sensors with composite circular resonant ring structures under the same test conditions (approximately 5.31%), demonstrating significant improvement. Therefore, the high-sensitivity microwave sensor of this invention can quickly and accurately acquire the resonant change of the test reagent with the corresponding dielectric constant, thereby determining the heavy metal content based on the calibration relationship between this resonant change and the heavy metal concentration. This enables high-precision detection of heavy metal content in liquid samples, suitable for rapid screening in pharmaceutical production sites or distribution channels.

[0056] Example 2

[0057] The difference between this embodiment and embodiment 1 is that the length F1 of the main arm 6 is 0.76 mm, the length F2 of the branch arm 7 is 0.64 mm, and the width FS of both the main arm 6 and the branch arm 7 is 0.088 mm; the ratio E of the length F2 of the branch arm 7 to the length F1 of the main arm 6 is approximately 0.84.

[0058] Comparative Example 1

[0059] The difference between this embodiment and embodiment 1 is that the length F1 of the main arm 6 is 0.78 mm, the length F2 of the branch arm 7 is 0.73 mm, and the width FS of both the main arm 6 and the branch arm 7 is 0.088 mm; the ratio E of the length F2 of the branch arm 7 to the length F1 of the main arm 6 is approximately 0.94.

[0060] Comparative Example 2

[0061] The difference between this embodiment and embodiment 1 is that the length F1 of the main arm 6 is 0.8 mm, the length F2 of the branch arm 7 is 0.624 mm, and the width FS of both the main arm 6 and the branch arm 7 is 0.088 mm; the ratio E of the length F2 of the branch arm 7 to the length F1 of the main arm 6 is approximately 0.80.

[0062] The microwave sensors of Examples 1 and 2 and Comparative Examples 1 and 2 were subjected to performance tests under the same test conditions, and the results were as follows: Figure 6 and 8 The S values ​​of microwave sensors with different dielectric constants are shown in Figure 10. 21 (Transmission parameters) The resonant point frequency deviation curve is used to obtain the sensitivity data for each example based on the data from each curve and the sensitivity calculation method. The specific test results are as follows:

[0063]

[0064] Based on the above test results and the S values ​​of microwave sensors under different dielectric constants... 21 (Transmission parameters) The frequency deviation curve of the resonant point shows that, compared with Comparative Examples 1 and 2, the microwave sensor's sensitivity is lower the further it is from the ratio E range in Examples 1 and 2. Microwave sensors within the ratio E range can achieve better matching effect, and the coupling strength between the capacitor arms is stronger, thereby reducing the degree of electromagnetic energy reflection deterioration on sensor sensitivity and improving the detection sensitivity of microwave sensors.

[0065] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A microwave sensor for detection of traditional Chinese medicine reagents, characterized in that, The medium plate is provided with a radiation layer on the top surface and a grounding layer on the bottom surface, and a radiation unit is etched in the radiation layer, and microstrip lines are arranged on the left and right sides of the radiation layer; The radiation unit comprises radiation ring grooves, and symmetrical converging modules are arranged on the left and right sides of the radiation ring grooves, and the converging modules are in communication with the radiation ring grooves and used for prolonging the current transmission path; Open ring capacitor arm modules are arranged in the middle part of the radiation ring grooves, and the two ends of the open ring capacitor arm modules are in communication with the radiation ring grooves through connection line grooves; The converging module comprises a spiral through groove, the starting end of the spiral through groove is in communication with the radiation ring groove, and the terminal end of the spiral through groove is located in the middle part; a line groove is arranged between the starting end and the terminal end, and the line groove is spirally arranged from outside to inside around the terminal end; The open ring capacitor arm module comprises an upper open ring capacitor arm and a lower open ring capacitor arm, and an open ring groove and a coupling capacitor arm are formed between the upper open ring capacitor arm and the lower open ring capacitor arm; the coupling capacitor arm is located in the open ring groove, and an opening structure is formed on the two sides of the open ring groove; The upper open ring capacitor arm comprises an upper half ring groove and an upper capacitor arm in communication with the upper half ring groove, and the middle part of the upper half ring groove is connected with the radiation ring groove through the connection line groove; the lower open ring capacitor arm comprises a lower half ring groove and a lower capacitor arm in communication with the lower half ring groove, and the middle part of the lower half ring groove is connected with the radiation ring groove through the connection line groove; the upper half ring groove and the lower half ring groove are arranged in a spaced manner and form the open ring groove; the upper capacitor arm and the lower capacitor arm are in a center point symmetry structure, and they form the coupling capacitor arm; The upper capacitor arm is a reverse F type capacitor arm, and the lower capacitor arm is an F type capacitor arm; the reverse F type capacitor arm and the F type capacitor arm each comprise a main stem arm, two branch stem arms are arranged vertically on the main stem arm, and the branch stem arms of the reverse F type capacitor arm are located below the branch stem arms of the F type capacitor arm.

2. The microwave sensor of claim 1, wherein, A plurality of vias and metal cylinders are arranged in a spaced manner on the upper and lower sides of the radiation layer, the metal cylinders are inserted into the medium plate and the grounding layer through the vias, and the metal cylinders are connected with the radiation layer and the grounding layer respectively; the radiation unit is located between the metal cylinders on the upper and lower sides.

3. The microwave sensor of claim 1, wherein, The ratio E of the length F2 of the branch stem arm to the length F1 of the main stem arm is E=F2 / F1, and the value range of E is 0.81<E<0.

92.

4. The microwave sensor of claim 3, wherein, The length F1 of the main stem arm is 0.73mm-0.77mm, the length F2 of the branch stem arm is 0.63mm-0.67mm, and the width FS of the main stem arm and the branch stem arm is 0.05mm-0.09mm.

5. The microwave sensor of claim 1, wherein, The shape of the spiral through groove is rectangular spiral, circular spiral or elliptical spiral.

6. The microwave sensor of claim 1, wherein, The microstrip line is a trapezoidal microstrip line, one end of the microstrip line is connected with an SMA joint, and the SMA joint is connected with an external network analyzer or an integrated microwave module.

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