Method, system and equipment for measuring microwave dielectric constant and storage medium

Abstract

The invention discloses a microwave dielectric constant measurement method, system and device and a storage medium, and relates to the field of measurement. In the method, a to-be-tested material is placed between a transmitting antenna and a receiving antenna, an incident angle is adjusted to a preset value, and a signal source is arranged to transmit a first electromagnetic wave signal and receive a second electromagnetic wave signal; calculating an amplitude ratio of the first electromagnetic wave signal to the second electromagnetic wave signal, and calculating a phase difference between the first electromagnetic wave signal and the second electromagnetic wave signal; constructing a waveguide transmission model according to the to-be-measured material, and calculating the characteristic impedance and the propagation constant of a transmission line of the waveguide transmission model according to the size and the working frequency of a waveguide in the waveguide transmission model and the thickness of the to-be-measured material; and constructing an equation set according to the amplitude ratio, the phase difference, the characteristic impedance and the propagation constant, and solving to obtain the microwave dielectric constant. By implementing the technical scheme provided by the invention, the dielectric constant can be accurately measured.

Description

Technical Field

[0001] The present application relates to the technical field of measurement, and specifically to a method, system, device and storage medium for measuring a microwave dielectric constant. Background Art

[0002] In geological exploration, the measurement of dielectric constant is of great significance for identifying underground rock strata, detecting mineral resources and evaluating surface moisture content, and has greatly promoted technological progress in related fields.

[0003] Existing microwave dielectric constant measurement methods mainly include free space method, resonant cavity method and waveguide transmission method. However, these existing methods still have some shortcomings in practical applications. For example, the free space method is greatly affected by environmental interference, the measurement results are unstable, and it is not suitable for complex geological environments; although the resonant cavity method has high accuracy, the equipment cost is high, the operation is complicated, and it is difficult to deploy quickly on site; although the waveguide transmission method has a wide range of applications, when dealing with different materials and different thicknesses, the waveguide size and parameters need to be frequently adjusted, which increases the measurement difficulty and time cost.

[0004] Therefore, a method that can adapt to complex environments and accurately measure the dielectric constant is needed. Summary of the invention

[0005] The present application provides a microwave dielectric constant measurement method, system, device and storage medium, which improves the measurement accuracy and can adapt to more complex environments.

[0006] In a first aspect of the present application, a method for measuring a microwave dielectric constant is provided, which is applied to a microwave dielectric constant measurement platform. The method comprises: The material to be tested is placed between the transmitting antenna and the receiving antenna, the incident angle is adjusted to a predetermined value, a signal source is set to transmit a first electromagnetic wave signal, and a second electromagnetic wave signal is received, wherein the second electromagnetic wave signal is an electromagnetic wave signal after the first electromagnetic wave signal passes through the material to be tested; Calculating an amplitude ratio of the first electromagnetic wave signal to the second electromagnetic wave signal, and calculating a phase difference between the first electromagnetic wave signal and the second electromagnetic wave signal; Constructing a waveguide transmission model according to the material to be tested, and calculating the characteristic impedance and propagation constant of the transmission line of the waveguide transmission model according to the size of the waveguide in the waveguide transmission model, the operating frequency and the thickness of the material to be tested; A set of equations is constructed according to the amplitude ratio, the phase difference, the characteristic impedance and the propagation constant, and the microwave dielectric constant is obtained by solving the equations.

[0007] Optionally, calculating the amplitude ratio of the first electromagnetic wave signal to the second electromagnetic wave signal, and calculating the phase difference between the first electromagnetic wave signal and the second electromagnetic wave signal includes: Calculating a root mean square value or a peak value of the first electromagnetic wave signal to obtain a first amplitude, calculating a root mean square value or a peak value of the second electromagnetic wave signal to obtain a second amplitude, and calculating a ratio of the second amplitude to the first amplitude to obtain an amplitude ratio; The difference between the second phase of the second electromagnetic wave signal and the first phase of the first electromagnetic wave is calculated, and the difference is unwrapped according to the history of phase change to obtain a phase difference.

[0008] Optionally, constructing a set of equations according to the amplitude ratio, the phase difference, the characteristic impedance and the propagation constant and solving them to obtain the microwave dielectric constant further includes: The attenuation of the electromagnetic wave in the material to be tested is obtained according to the amplitude ratio, and the attenuation coefficient is calculated according to the attenuation; the phase delay of the electromagnetic wave in the material to be tested is obtained according to the phase difference, and the phase constant is calculated according to the phase delay.

[0009] Optionally, constructing a waveguide transmission model according to the material to be tested includes: Determine the size of the waveguide according to the shape, size and test requirements of the material to be tested, wherein the size includes length, width, height or diameter; Establishing a geometric model according to the size and the thickness of the material to be measured; The electromagnetic properties of the material to be tested are set in the geometric model, including relative dielectric constant, relative magnetic permeability and electrical conductivity; the boundary conditions of the waveguide are set, and the boundary conditions include the electrical conductivity of the metal wall and the conditions of a perfect electrical conductor or a perfect magnetic conductor, so as to ensure that the transmission of electromagnetic waves in the waveguide complies with physical laws.

[0010] Optionally, the calculating the characteristic impedance and propagation constant of the transmission line of the waveguide transmission model according to the size of the waveguide in the waveguide transmission model, the operating frequency and the thickness of the material to be measured includes: The characteristic impedance is calculated by the width and height of the waveguide, the wave number of the operating frequency and the electromagnetic properties of the material to be measured; the phase constant is calculated by the size of the waveguide and the operating frequency, the attenuation constant is determined by the size of the waveguide, the operating frequency, the electromagnetic properties of the material to be measured and the roughness of the waveguide surface, and the propagation constant is determined based on the phase constant and the attenuation constant.

[0011] Optionally, constructing a set of equations according to the amplitude ratio, the phase difference, the characteristic impedance and the propagation constant and solving them to obtain the microwave dielectric constant includes: Constructing voltage and current equations at a target location of the transmission line by using the voltage amplitude, propagation constant and characteristic impedance of the first electromagnetic wave signal and the second electromagnetic wave signal; The first relationship equation between S parameters and transmission line parameters is constructed by using load impedance, characteristic impedance, propagation constant and transmission line length; the second relationship equation between dielectric constant and propagation constant is constructed by using angular frequency and complex magnetic permeability; A set of equations is constructed by using the voltage and current equations, the first relationship equation and the second relationship equation, and the microwave dielectric constant is obtained by solving the set of equations by an iterative method.

[0012] Optionally, the method comprises: The voltage and current equations at the target location of the transmission line are constructed using the following formulas: V(z)=V 0 + e -γz +V 0 - e γz Where V(z) and I(z) are the voltage and current at the target position z, respectively. 0 + and V 0 - are the voltage amplitudes of the first electromagnetic wave signal and the second electromagnetic wave signal, γ is the propagation constant, and Z 0 is the characteristic impedance, The first relationship equation between S parameters and transmission line parameters is constructed by the following formula: Where R is the reflection coefficient of the transmission line, T is the transmission coefficient of the transmission line, and Z L is the load impedance, d is the transmission line length, and the second relationship between the dielectric constant and the propagation constant is constructed by the following formula: Where ω is the angular frequency, α is the attenuation constant, β is the phase constant, j is the imaginary unit, ∈ is the dielectric constant, ∈ 0 is the dielectric constant of vacuum, μ 0 is the vacuum permeability, μ is the complex permeability, ∈ ′ is the real part of the dielectric constant, ∈ ″ is the imaginary part of the dielectric constant.

[0013] In a second aspect of the present application, a microwave dielectric constant measurement system is provided, comprising a signal module, a calculation module, a model module and an execution module, wherein: A signal module is configured to place the material to be tested between the transmitting antenna and the receiving antenna, adjust the incident angle to a predetermined value, set the signal source to transmit a first electromagnetic wave signal, and receive a second electromagnetic wave signal, wherein the second electromagnetic wave signal is an electromagnetic wave signal after the first electromagnetic wave signal passes through the material to be tested; a calculation module, configured to calculate an amplitude ratio of the first electromagnetic wave signal and the second electromagnetic wave signal, and calculate a phase difference between the first electromagnetic wave signal and the second electromagnetic wave signal; A model module, configured to construct a waveguide transmission model according to the material to be tested, and calculate the characteristic impedance and propagation constant of the transmission line of the waveguide transmission model according to the size of the waveguide in the waveguide transmission model, the operating frequency and the thickness of the material to be tested; An execution module is configured to construct a set of equations according to the amplitude ratio, the phase difference, the characteristic impedance and the propagation constant and solve them to obtain the microwave dielectric constant.

[0014] In the third aspect of the present application, an electronic device is provided, including a processor, a memory, a user interface and a network interface, the memory is used to store instructions, the user interface and the network interface are both used to communicate with other devices, and the processor is used to execute the instructions stored in the memory so that the electronic device executes any one of the methods described above.

[0015] In a fourth aspect of the present application, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores instructions, and when the instructions are executed, any of the methods described above is executed.

[0016] In summary, one or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages: 1. By accurately measuring the amplitude ratio and phase difference between the first electromagnetic wave signal and the second electromagnetic wave signal, combined with the transmission line characteristic impedance and propagation constant of the waveguide transmission model, a high-precision set of equations can be constructed. Solving the set of equations can obtain the microwave dielectric constant of the material to be measured. This method has higher measurement accuracy than traditional methods. 2. Use transmitting antenna and receiving antenna to transmit and receive electromagnetic wave signals, without direct contact with the material to be tested. This non-contact measurement method can reduce the error caused by contact, and is suitable for materials of various shapes and sizes to be tested, improving the versatility and flexibility of measurement; 3. Applicable to various types of microwave materials, including solids, liquids and films. By adjusting the incident angle of the transmitting antenna and the operating frequency of the signal source, it can meet the measurement requirements of different materials and broaden the scope of application of the measurement method; 4. Since electromagnetic wave signals are used for measurement, the measurement process is fast and multiple samples can be measured in a short time. This improves the measurement efficiency and is suitable for rapid screening and evaluation in large-scale production and scientific research experiments; 5. By constructing a waveguide transmission model and calculating the characteristic impedance and propagation constant of the transmission line, the complex electromagnetic wave transmission process can be converted into a mathematical model for analysis. This helps to deeply understand the transmission mechanism of electromagnetic waves in the material to be tested and provide theoretical support for the optimization of material performance; 6. Since multiple measurement parameters (amplitude ratio, phase difference, characteristic impedance and propagation constant) are combined and the microwave dielectric constant is obtained by solving a set of equations, the measurement data has high reliability and repeatability, which helps to ensure the accuracy and consistency of the measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic flow chart of a method for measuring a microwave dielectric constant disclosed in an embodiment of the present application; Figure 2 It is a module schematic diagram of a microwave dielectric constant measurement system disclosed in an embodiment of the present application; Figure 3 It is a structural schematic diagram of an electronic device disclosed in an embodiment of the present application.

[0018] Explanation of the reference numerals: 201, signal module; 202, calculation module; 203, model module; 204, execution module; 301, processor; 302, communication bus; 303, user interface; 304, network interface; 305, memory. DETAILED DESCRIPTION

[0019] In order to enable technicians in this field to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments.

[0020] In the description of the embodiments of the present application, words such as "for example" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "for example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "for example" or "for example" is intended to present related concepts in a specific way.

[0021] In the description of the embodiments of the present application, the meaning of the term "multiple" refers to two or more. For example, multiple systems refer to two or more systems, and multiple screen terminals refer to two or more screen terminals. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. The terms "include", "comprise", "have" and their variations all mean "including but not limited to", unless otherwise specifically emphasized.

[0022] This embodiment discloses a microwave dielectric constant measurement method, which is applied to a microwave dielectric constant measurement platform. Figure 1 is a schematic flow chart of the microwave dielectric constant measurement method disclosed in the embodiment of the present application, such as Figure 1 As shown, the method comprises the following steps: S110, placing the material to be tested between the transmitting antenna and the receiving antenna, adjusting the incident angle to a predetermined value, setting the signal source to transmit a first electromagnetic wave signal, and receiving a second electromagnetic wave signal, wherein the second electromagnetic wave signal is an electromagnetic wave signal after the first electromagnetic wave signal passes through the material to be tested; Select appropriate transmitting antenna, receiving antenna, signal source and measuring equipment. The selection of these equipment should be based on the characteristics of the material to be tested, the measurement frequency range and the required measurement accuracy. Process the material to be tested into an appropriate shape and size so that it can be placed between the transmitting antenna and the receiving antenna. At the same time, ensure that the surface of the material to be tested is flat and defect-free to reduce measurement errors. Place the material to be tested at a predetermined position between the transmitting antenna and the receiving antenna. To ensure the accuracy of the measurement, the material to be tested should be fixed with an appropriate fixture or bracket to prevent it from moving or deforming during the measurement. Adjust the incident angle of the transmitting antenna to a predetermined value as required. The selection of the incident angle should be based on the characteristics of the material to be tested and the required measurement sensitivity. By adjusting the incident angle, the propagation path and reflection characteristics of the electromagnetic wave in the material to be tested can be changed, thereby affecting the measurement results. Set the signal source to the required frequency and power to transmit the first electromagnetic wave signal. The selection of the signal source should ensure that the generated electromagnetic wave signal has a stable frequency and power to reduce measurement errors. Start the signal source so that the transmitting antenna transmits the first electromagnetic wave signal. The electromagnetic wave signal will pass through the material to be tested and propagate inside it. The receiving antenna receives the second electromagnetic wave signal, that is, the electromagnetic wave signal after the first electromagnetic wave signal passes through the material to be tested. The receiving antenna should be placed in an appropriate position to ensure that the electromagnetic wave signal after passing through the material to be tested can be accurately received. Use the measuring equipment to measure the amplitude and phase of the first electromagnetic wave signal and the second electromagnetic wave signal. These parameters will be used for subsequent data processing and calculation. The measured amplitude and phase data are recorded for subsequent analysis and processing. At the same time, the experimental conditions (such as incident angle, signal source frequency, power, etc.) and the characteristics of the material to be tested (such as size, shape, material, etc.) should also be recorded.

[0023] S120, calculating an amplitude ratio of the first electromagnetic wave signal to the second electromagnetic wave signal, and calculating a phase difference between the first electromagnetic wave signal and the second electromagnetic wave signal; The amplitude ratio refers to the ratio between the amplitude of the second electromagnetic wave signal and the amplitude of the first electromagnetic wave signal. It reflects the attenuation of the amplitude of the electromagnetic wave signal after passing through the material to be tested. Use appropriate measuring equipment (such as vector network analyzer, oscilloscope, etc.) to measure the amplitude of the first electromagnetic wave signal and the second electromagnetic wave signal respectively. These devices can capture the peak value or effective value of the signal, thereby providing accurate amplitude information. Divide the amplitude of the second electromagnetic wave signal by the amplitude of the first electromagnetic wave signal to obtain the amplitude ratio. This ratio is usually a number less than one because it indicates the attenuation of the signal after passing through the material to be tested. The phase difference refers to the phase offset between the first electromagnetic wave signal and the second electromagnetic wave signal. It reflects the delay or advance of the phase of the electromagnetic wave signal after passing through the material to be tested. Also use measuring equipment (such as vector network analyzer) to measure the phase of the first electromagnetic wave signal and the second electromagnetic wave signal respectively. These devices can capture the phase information of the signal, usually expressed in degrees (°) or radians (rad). Subtract the phase of the first electromagnetic wave signal from the phase of the second electromagnetic wave signal to obtain the phase difference. This difference may be positive or negative, indicating the phase delay or advance of the signal after passing through the material under test.

[0024] Optionally, calculating the amplitude ratio of the first electromagnetic wave signal to the second electromagnetic wave signal, and calculating the phase difference between the first electromagnetic wave signal and the second electromagnetic wave signal includes: Calculating a root mean square value or a peak value of the first electromagnetic wave signal to obtain a first amplitude, calculating a root mean square value or a peak value of the second electromagnetic wave signal to obtain a second amplitude, and calculating a ratio of the second amplitude to the first amplitude to obtain an amplitude ratio; The difference between the second phase of the second electromagnetic wave signal and the first phase of the first electromagnetic wave is calculated, and the difference is unwrapped according to the history of phase change to obtain a phase difference.

[0025] Use a measuring device (such as a vector network analyzer, oscilloscope, etc.) to measure the root mean square (RMS) value or peak value of the first electromagnetic wave signal. The root mean square value reflects the average power of the signal, while the peak value reflects the maximum instantaneous value of the signal. Which value to choose depends on the specific needs of the experiment and the characteristics of the measuring device. Similarly, measure the root mean square value or peak value of the second electromagnetic wave signal. The root mean square value or peak value represents the amplitude of the signal after passing through the material to be tested. Divide the second amplitude by the first amplitude to obtain the amplitude ratio. This ratio reflects the attenuation degree of the electromagnetic wave signal after passing through the material to be tested. If the amplitude ratio is close to 1, it means that the signal attenuation is very small; if the amplitude ratio is much less than 1, it means that the signal attenuation is large. Use a measuring device to measure the phase of the first electromagnetic wave signal. Phase is a parameter that describes the position or offset of the signal waveform relative to a reference point (such as the zero phase point). Similarly, measure the phase of the second electromagnetic wave signal. This value represents the phase of the signal after passing through the material to be tested. Directly subtract the first phase from the second phase to obtain a preliminary phase difference value. However, since the phase changes periodically (usually between 0° and 360°, or between 0 and 2π radians), this preliminary difference may be affected by periodic jumps, the so-called "wrapping" phenomenon. In order to obtain the true phase difference, the preliminary difference needs to be unwrapped. The purpose of unwrapping is to eliminate the error caused by periodic jumps and thus restore the true phase change history. This usually involves checking the phase difference of adjacent data points and correcting the wrapping phenomenon by adding or subtracting an appropriate multiple (usually 360° or 2π radians) as needed.

[0026] By calculating the root mean square value or peak value of the electromagnetic wave signal, the amplitude characteristics of the signal can be more accurately reflected, and the errors caused by signal fluctuations or noise can be reduced. In the calculation of the phase difference, the periodic error caused by the phase exceeding 360° (or 2π radians) can be corrected by unwinding the history of phase changes, thereby obtaining a more accurate phase difference value. The calculation of the amplitude ratio and phase difference are based on the results of multiple measurements. The reliability and stability of the data can be further improved by taking the average value or performing other statistical processing. The unwinding process can also ensure the continuity of the phase difference and avoid measurement errors caused by sudden phase changes. Accurate amplitude ratio and phase difference are the basis for constructing a set of equations and solving the microwave dielectric constant. By improving the measurement accuracy of these two parameters, the subsequent data analysis and processing process can be optimized to obtain more accurate dielectric constant results.

[0027] S130, construct a waveguide transmission model according to the material to be tested, and calculate the characteristic impedance and propagation constant of the transmission line of the waveguide transmission model according to the size of the waveguide in the waveguide transmission model, the operating frequency and the thickness of the material to be tested; clarify the type of waveguide used (such as rectangular waveguide, circular waveguide, etc.) and its specific size (such as width, height, radius, etc.). These sizes will directly affect the electromagnetic wave mode and transmission characteristics in the waveguide. The operating frequency is the frequency of electromagnetic waves when they are transmitted in the waveguide. Different frequencies will lead to different transmission modes and loss characteristics. Therefore, when building the model, it is necessary to accurately set the operating frequency. The material to be tested is introduced into the model as part of the waveguide or filler. This requires consideration of the thickness of the material, the dielectric constant (to be tested) and possible loss characteristics. Characteristic impedance is an important parameter of the transmission line, which represents the ratio of voltage to current on the transmission line. In the waveguide transmission model, the characteristic impedance is related to the size of the waveguide, the operating frequency and the electromagnetic properties of the material. For different types of waveguides, the calculation formula of the characteristic impedance will be different. For example, in a rectangular waveguide, the characteristic impedance can be determined by the width, height and operating frequency of the waveguide. The propagation constant describes the propagation characteristics of electromagnetic waves in the transmission line, including phase change and attenuation. It contains a real part and an imaginary part, which represent the phase constant and the attenuation constant respectively. In the waveguide transmission model, the propagation constant is related to the size of the waveguide, the operating frequency, the dielectric constant of the material, and the loss characteristics. By solving the electromagnetic wave equation in the waveguide, the specific value of the propagation constant can be obtained.

[0028] Optionally, constructing a waveguide transmission model according to the material to be tested includes: Determine the size of the waveguide according to the shape, size and test requirements of the material to be tested, wherein the size includes length, width, height or diameter; Establishing a geometric model according to the size and the thickness of the material to be measured; The electromagnetic properties of the material to be tested are set in the geometric model, including relative dielectric constant, relative magnetic permeability and electrical conductivity; the boundary conditions of the waveguide are set, and the boundary conditions include the electrical conductivity of the metal wall and the conditions of a perfect electrical conductor or a perfect magnetic conductor, so as to ensure that the transmission of electromagnetic waves in the waveguide complies with physical laws.

[0029] According to the shape of the material to be tested (such as block, sheet, cylindrical, etc.) and the test requirements (such as frequency range, transmission mode, etc.), select the appropriate waveguide type (such as rectangular waveguide, circular waveguide, etc.) and determine its size. These dimensions usually include length, width, height (for rectangular waveguide) or diameter (for circular waveguide). The size selection of the waveguide should ensure that the electromagnetic wave can be stably transmitted in the waveguide in the required mode within the required operating frequency range. This may require optimizing the size selection by calculating parameters such as cutoff frequency and transmission characteristics. According to the determined waveguide size and the thickness of the material to be tested, use CAD software or other geometric modeling tools to establish a geometric model of the waveguide. This model should accurately reflect the actual shape and size of the waveguide. In the geometric model, the material to be tested is introduced into the waveguide as a filler or part. Ensure that the shape, size and position of the material are consistent with the actual situation in order to accurately simulate the transmission process of electromagnetic waves in the waveguide. In the geometric model, set the correct electromagnetic properties for the material to be tested, including relative dielectric constant, relative magnetic permeability and electrical conductivity. These parameters will directly affect the propagation characteristics of electromagnetic waves in the material. According to the actual electromagnetic properties of the material to be tested, select appropriate electromagnetic parameter values. If possible, standard samples can be used for calibration to ensure that the set parameter values ​​are accurate and reliable. For the metal wall of the waveguide, a suitable conductivity value should be set. This is usually a very high value to simulate the perfect conductivity of the metal wall. According to the transmission characteristics of the electromagnetic wave in the waveguide, select appropriate boundary conditions. For example, the perfect electric conductor (PEC) condition can be used to simulate the reflection and transmission characteristics of the metal wall to the electromagnetic wave; or the perfect magnetic conductor (PMC) condition can be used to simulate the behavior of electromagnetic waves in some special cases. After setting the boundary conditions, the model should be verified and adjusted using electromagnetic simulation software. By comparing the differences between the simulation results and the expected results, the setting of the boundary conditions can be further optimized.

[0030] By determining the size of the waveguide according to the shape, size and test requirements of the material to be tested, the model can be highly matched with the actual situation, thereby improving the accuracy of the simulation results. When establishing the geometric model, considering the thickness of the material to be tested helps to more realistically reflect the propagation of electromagnetic waves in the material. Setting the electromagnetic properties of the material to be tested in the geometric model, such as relative dielectric constant, relative magnetic permeability and electrical conductivity, is the key to simulating the propagation behavior of electromagnetic waves in the material. The accurate setting of these parameters can ensure that the model accurately describes the electromagnetic properties of the material. Setting the boundary conditions of the waveguide, such as the conductivity of the metal wall and the conditions of perfect electrical conductor or perfect magnetic conductor, is an important step to ensure that the transmission of electromagnetic waves in the waveguide conforms to the laws of physics. The setting of these boundary conditions can simulate the actual propagation of electromagnetic waves in the waveguide, thereby obtaining more realistic simulation results. An accurate waveguide transmission model provides the basis for the subsequent calculation of characteristic impedance and propagation constant. By building an accurate model, the subsequent data analysis and processing process can be optimized to obtain more accurate transmission line parameters. In addition, an accurate model can also provide a reference for the measurement and analysis of other related parameters, such as the loss characteristics of the material, impedance matching, etc.

[0031] Optionally, the calculating the characteristic impedance and propagation constant of the transmission line of the waveguide transmission model according to the size of the waveguide in the waveguide transmission model, the operating frequency and the thickness of the material to be measured includes: The characteristic impedance is calculated by the width and height of the waveguide, the wave number of the operating frequency and the electromagnetic properties of the material to be measured; the phase constant is calculated by the size of the waveguide and the operating frequency, the attenuation constant is determined by the size of the waveguide, the operating frequency, the electromagnetic properties of the material to be measured and the roughness of the waveguide surface, and the propagation constant is determined based on the phase constant and the attenuation constant.

[0032] Characteristic impedance is an important parameter of the transmission line, which describes the ratio of voltage to current on the transmission line. In the waveguide transmission model, the calculation of characteristic impedance usually involves the width, height, wave number of the operating frequency of the waveguide (that is, the phase change per unit length of the electromagnetic wave propagating in the waveguide, which is proportional to the frequency) and the electromagnetic properties of the material to be tested (such as relative dielectric constant and relative magnetic permeability). The propagation constant is an important parameter that describes the propagation characteristics of electromagnetic waves in the transmission line. It includes two parts: phase constant and attenuation constant. The phase constant describes the phase change caused by the electromagnetic wave per unit length in the transmission line. It is usually related to the size of the waveguide, the operating frequency, and the propagation mode of the electromagnetic wave. For a given waveguide and operating frequency, the phase constant can be obtained by solving the electromagnetic wave equation in the waveguide. The attenuation constant describes the energy loss of the electromagnetic wave when it propagates in the transmission line. It is affected by many factors, including the size of the waveguide, the operating frequency, the electromagnetic properties of the material to be tested, and the roughness of the waveguide surface. The roughness of the waveguide surface will increase the scattering and reflection of the electromagnetic wave, resulting in additional energy loss. Therefore, when calculating the attenuation constant, the combined effects of these factors need to be considered. Once the phase constant and the attenuation constant are obtained, the propagation constant can be obtained by adding them. The propagation constant is a complex number, whose real part represents the attenuation constant and the imaginary part represents the phase constant.

[0033] Characteristic impedance is an important parameter to describe the inherent impedance characteristics of transmission lines. By accurately calculating the characteristic impedance, the relationship between voltage and current of the transmission line during electromagnetic wave transmission can be more accurately described, so as to better understand the transmission characteristics of the transmission line. In microwave circuits, impedance matching is crucial. By calculating the characteristic impedance, circuit elements that match the impedance of the transmission line can be designed, thereby reducing signal reflection and loss and improving the transmission efficiency of the circuit. In microwave measurement, the accurate calculation of characteristic impedance has an important influence on the accuracy of the measurement results. By optimizing the calculation method, the calculation accuracy of characteristic impedance can be improved, thereby improving the accuracy and reliability of the entire measurement system. The propagation constant includes two components: phase constant and attenuation constant, which respectively describe the phase change and attenuation of electromagnetic waves on the transmission line. By calculating the propagation constant, the performance of the transmission line can be fully reflected, providing an important basis for subsequent circuit design and optimization. The calculation of the propagation constant can also be used to predict the transmission quality of the signal on the transmission line. By calculating the phase constant and attenuation constant, the phase change and attenuation of the signal during transmission can be estimated, thereby predicting the transmission quality of the signal and providing a reference for subsequent testing and optimization.

[0034] S140, constructing a set of equations according to the amplitude ratio, the phase difference, the characteristic impedance and the propagation constant, and solving them to obtain a microwave dielectric constant.

[0035] According to the transmission line theory, the propagation equations of electromagnetic waves on the transmission line can be established based on the characteristic impedance and propagation constant. These equations will contain the microwave dielectric constant to be solved. The amplitude ratio and phase difference obtained by experiment or simulation are substituted into the transmission line equation as known conditions. These conditions will help us determine the unknown parameters in the system of equations, including the microwave dielectric constant. By integrating the above information, a system of equations containing multiple equations can be constructed. These equations will involve multiple parameters such as amplitude ratio, phase difference, characteristic impedance and propagation constant, and jointly constrain the value of the microwave dielectric constant. The system of equations is usually nonlinear, so numerical methods are needed to solve it. Commonly used numerical methods include iteration methods, optimization algorithms, etc. In the solution process, it may be necessary to approximate the true solution through parameter estimation. This can be achieved by using known physical laws and experimental data. After solving, the results need to be verified. This can be achieved by substituting the solved microwave dielectric constant into the original system of equations for verification. If the results do not meet expectations, they need to be corrected and the system of equations need to be solved again.

[0036] Optionally, constructing a set of equations according to the amplitude ratio, the phase difference, the characteristic impedance and the propagation constant and solving them to obtain the microwave dielectric constant further includes: The attenuation of the electromagnetic wave in the material to be tested is obtained according to the amplitude ratio, and the attenuation coefficient is calculated according to the attenuation; the phase delay of the electromagnetic wave in the material to be tested is obtained according to the phase difference, and the phase constant is calculated according to the phase delay.

[0037] The attenuation of the electromagnetic wave in the material to be tested can be calculated using the amplitude ratio of the electromagnetic wave before and after passing through the material to be tested. This attenuation is converted into an attenuation coefficient, which reflects the attenuation degree of the electromagnetic wave intensity per unit length. Measure or calculate the phase difference of the electromagnetic wave before and after passing through the material to be tested. Using this phase difference and the thickness of the material to be tested, the phase delay of the electromagnetic wave in the material to be tested can be calculated. Divide this phase delay by the thickness of the material to obtain the phase constant, which reflects the degree of change in the phase of the electromagnetic wave per unit length. After obtaining the attenuation coefficient and phase constant, the characteristic impedance and propagation constant can be combined to construct a set of equations. This set of equations will contain multiple unknown parameters, including the microwave dielectric constant.

[0038] By directly extracting the attenuation from the amplitude ratio and calculating the attenuation coefficient based on it, the energy loss of electromagnetic waves in the material to be tested can be described more accurately. This helps to reduce the measurement error caused by energy loss and improve the accuracy of microwave dielectric constant measurement. The phase difference reflects the phase delay of electromagnetic waves when they propagate in the material to be tested. By calculating the phase delay and deriving the phase constant, we can have a deeper understanding of the propagation characteristics of electromagnetic waves in the material, especially its phase change. This helps to make more comprehensive use of phase information and improve the comprehensiveness and accuracy of the measurement. The introduction of the attenuation coefficient and phase constant makes the construction of the equation group more complete and accurate. These two parameters together with the characteristic impedance and propagation constant constitute a complete set of equations that describe the propagation characteristics of electromagnetic waves in the material to be tested. By solving this set of equations, we can obtain a more accurate microwave dielectric constant. When constructing the equation group, by directly using the attenuation coefficient and phase constant calculated from the amplitude ratio and phase difference, additional calculation steps and complexity can be reduced. This helps to improve the solution efficiency and make the entire measurement process more efficient and convenient.

[0039] Optionally, constructing a set of equations according to the amplitude ratio, the phase difference, the characteristic impedance and the propagation constant and solving them to obtain the microwave dielectric constant includes: Constructing voltage and current equations at a target location of the transmission line by using the voltage amplitude, propagation constant and characteristic impedance of the first electromagnetic wave signal and the second electromagnetic wave signal; The first relationship equation between S parameters and transmission line parameters is constructed by using load impedance, characteristic impedance, propagation constant and transmission line length; the second relationship equation between dielectric constant and propagation constant is constructed by using angular frequency and complex magnetic permeability; A set of equations is constructed by using the voltage and current equations, the first relationship equation and the second relationship equation, and the microwave dielectric constant is obtained by solving the set of equations by an iterative method.

[0040] The voltage amplitude, propagation constant and characteristic impedance of the first electromagnetic wave signal and the second electromagnetic wave signal are used to construct the voltage and current equations at the target position of the transmission line. These equations describe the voltage and current distribution when the electromagnetic wave signal propagates on the transmission line, and are the basis for the subsequent construction of the equation group. The load impedance, characteristic impedance, propagation constant and transmission line length are used to construct the first relationship equation between S parameters (scattering parameters) and transmission line parameters. S parameters are important parameters that describe the characteristics of microwave network ports. There is a specific relationship between them and the parameters of the transmission line (such as characteristic impedance, propagation constant, etc.). By constructing this relationship equation, the measurement results of S parameters can be linked to the physical parameters of the transmission line. The angular frequency and complex permeability are used to construct the second relationship equation between the dielectric constant and the propagation constant. This equation reflects the physical connection between the dielectric constant and the propagation constant and is the key to solving the microwave dielectric constant. The above three equations are integrated into a set of equations. This set of equations contains multiple unknown parameters, including microwave dielectric constant, propagation constant, characteristic impedance, etc. By solving this set of equations, the values ​​of these unknown parameters can be obtained. Since the set of equations is usually nonlinear, an iterative method is used to solve it. The iteration method is a method that gradually approaches the true solution, gradually reducing the error by continuously updating the values ​​of unknown parameters. In the solution process, known physical laws and experimental data can be used to set the initial value and iteration step to ensure the stability and accuracy of the solution process.

[0041] The voltage and current equations at the target position of the transmission line are constructed by the voltage amplitude, propagation constant and characteristic impedance of the first electromagnetic wave signal and the second electromagnetic wave signal. These equations can accurately describe the propagation characteristics of electromagnetic waves on the transmission line, including the distribution of voltage and current. The first relationship equation between S parameters (scattering parameters) and transmission line parameters is constructed by load impedance, characteristic impedance, propagation constant and transmission line length. S parameters are important parameters in microwave network analysis, which can reflect the scattering relationship between the input and output ports of the network. The establishment of this relationship enables us to indirectly obtain parameter information of the transmission line by measuring S parameters. The second relationship equation between dielectric constant and propagation constant is constructed by angular frequency and complex magnetic permeability. This equation reveals the intrinsic connection between dielectric constant and propagation constant, and provides a theoretical basis for solving dielectric constant by measuring propagation constant. By combining the above three equations into a set of equations and solving them by iterative method, the accurate value of microwave dielectric constant can be obtained. Iterative method is an efficient numerical solution method that can improve calculation efficiency while ensuring solution accuracy.

[0042] Optionally, the method comprises: The voltage and current equations at the target location of the transmission line are constructed using the following formulas: V(z)=V 0 + e-γz +V 0 - e γz Where V(z) and I(z) are the voltage and current at the target position z, respectively. 0 + and V 0 - are the voltage amplitudes of the first electromagnetic wave signal and the second electromagnetic wave signal, γ is the propagation constant, and Z 0 is the characteristic impedance, The first relationship equation between S parameters and transmission line parameters is constructed by the following formula: Where R is the reflection coefficient of the transmission line, T is the transmission coefficient of the transmission line, and Z L is the load impedance, d is the transmission line length, and the second relationship between the dielectric constant and the propagation constant is constructed by the following formula: Where ω is the angular frequency, α is the attenuation constant, β is the phase constant, j is the imaginary unit, ∈ is the dielectric constant, ∈ 0 is the dielectric constant of vacuum, μ 0 is the vacuum permeability, μ is the complex permeability, ∈ ′ is the real part of the dielectric constant, ∈ ″ is the imaginary part of the dielectric constant.

[0043] The voltage equation indicates that the voltage at the starting point z on the transmission line is the superposition of the voltage amplitudes of the first electromagnetic wave signal and the second electromagnetic wave signal, where e -γz and e γz They represent the attenuation and phase change of the first electromagnetic wave signal and the second electromagnetic wave signal with distance z. The current equation represents the relationship between the current and voltage at the starting point z on the transmission line. 0 The S parameter is a complex parameter that describes the input-output relationship of a two-port network. For a transmission line, the S parameter is closely related to the reflection coefficient R and the transmission coefficient T of the transmission line. The reflection coefficient indicates the load impedance Z encountered by the electromagnetic wave at the end of the transmission line. L The ratio of the electromagnetic wave reflected back to the transmission line when the load impedance does not match the characteristic impedance. Reflection occurs. The magnitude and phase of the reflection coefficient depend on the ratio of the load impedance to the characteristic impedance. The transmission coefficient indicates the ratio of the electromagnetic wave transmitted from one end of the transmission line to the other end. It depends on the load impedance, the characteristic impedance, the length d of the transmission line, and the propagation constant γ. In microwave measurement, the normalized S parameter, i.e. S 11 = R and S 21=T, which represent the measured values ​​of reflection coefficient and transmission coefficient respectively. For waveguides or coaxial transmission lines filled with uniform dielectrics, there is a specific relationship between the propagation constant and the dielectric constant and complex magnetic permeability. In the microwave band, the magnetic permeability is usually close to the magnetic permeability μ in vacuum. 0 The propagation constant is a complex number, which contains two components: the attenuation constant α and the phase constant β. The attenuation constant represents the attenuation of the energy of the electromagnetic wave during the transmission process, while the phase constant represents the change of the phase of the electromagnetic wave during the transmission process. The dielectric constant is a complex parameter that describes the electrical properties of the medium. It contains the real part ∈ ′ and the imaginary part∈ ″ . The real part represents the storage capacity of the medium for the electric field, while the imaginary part represents the loss capacity of the medium for the electric field. The relationship between the propagation constant and the dielectric constant can be derived from Maxwell's equations. In the microwave frequency band, since the magnetic permeability is close to the magnetic permeability in a vacuum, the propagation constant can be expressed as a function of the dielectric constant. This relationship equation is the key to solving the dielectric constant. Combining the above equations, we can get a set of equations containing the dielectric constant to be determined. This set of equations is usually nonlinear, so numerical methods need to be used to solve it. Commonly used numerical methods include iterative methods and optimization algorithms. The iterative method continuously updates the estimated value of the dielectric constant until the set of equations is established or the predetermined number of iterations is reached. The optimization algorithm finds the optimal solution for the dielectric constant that makes the set of equations valid by minimizing the error function in the set of equations.

[0044] By accurately constructing the transmission line equation, the propagation behavior of electromagnetic waves on the transmission line can be accurately described, including the distribution of voltage and current. This helps to reduce the measurement error caused by the transmission line effect and improve the accuracy of microwave dielectric constant measurement. The S parameters used are standard parameters in microwave network analysis and are applicable to various microwave circuits and transmission line structures. Therefore, it can be widely used in different types of microwave dielectric constant measurements, enhancing the versatility of the measurement. By constructing the relationship equation between S parameters and transmission line parameters, the parameter information of the transmission line can be directly obtained by measuring the S parameters without complex physical measurements or model fitting. This simplifies the measurement process and improves the measurement efficiency. The proposal and implementation of the embodiment of the present application provide new ideas and technical means for the measurement of microwave dielectric constants. By continuously optimizing and improving the embodiments of the present application, the development and innovation of microwave measurement technology can be promoted, and strong support can be provided for research and application in related fields.

[0045] This embodiment also discloses a microwave dielectric constant measurement system. Figure 2 Schematic diagram of a module of a microwave dielectric constant measurement system disclosed in an embodiment of the present application. Figure 2 As shown, the system includes a signal module 201, a calculation module 202, a model module 203 and an execution module 204, wherein: The signal module 201 is configured to place the material to be tested between the transmitting antenna and the receiving antenna, adjust the incident angle to a predetermined value, set the signal source to transmit a first electromagnetic wave signal, and receive a second electromagnetic wave signal, where the second electromagnetic wave signal is an electromagnetic wave signal after the first electromagnetic wave signal passes through the material to be tested; A calculation module 202, configured to calculate an amplitude ratio between the first electromagnetic wave signal and the second electromagnetic wave signal, and calculate a phase difference between the first electromagnetic wave signal and the second electromagnetic wave signal; A model module 203 is configured to construct a waveguide transmission model according to the material to be tested, and calculate the characteristic impedance and propagation constant of the transmission line of the waveguide transmission model according to the size of the waveguide in the waveguide transmission model, the operating frequency and the thickness of the material to be tested; The execution module 204 is configured to construct a set of equations according to the amplitude ratio, the phase difference, the characteristic impedance and the propagation constant and solve them to obtain the microwave dielectric constant.

[0046] Optionally, the calculation module 202 is configured to: Calculating a root mean square value or a peak value of the first electromagnetic wave signal to obtain a first amplitude, calculating a root mean square value or a peak value of the second electromagnetic wave signal to obtain a second amplitude, and calculating a ratio of the second amplitude to the first amplitude to obtain an amplitude ratio; The difference between the second phase of the second electromagnetic wave signal and the first phase of the first electromagnetic wave is calculated, and the difference is unwrapped according to the history of phase change to obtain a phase difference.

[0047] Optionally, the execution module 204 is configured to: The attenuation of the electromagnetic wave in the material to be tested is obtained according to the amplitude ratio, and the attenuation coefficient is calculated according to the attenuation; the phase delay of the electromagnetic wave in the material to be tested is obtained according to the phase difference, and the phase constant is calculated according to the phase delay.

[0048] Optionally, the model module 203 is configured to: Determine the size of the waveguide according to the shape, size and test requirements of the material to be tested, wherein the size includes length, width, height or diameter; Establishing a geometric model according to the size and the thickness of the material to be measured; The electromagnetic properties of the material to be tested are set in the geometric model, including relative dielectric constant, relative magnetic permeability and electrical conductivity; the boundary conditions of the waveguide are set, and the boundary conditions include the electrical conductivity of the metal wall and the conditions of a perfect electrical conductor or a perfect magnetic conductor, so as to ensure that the transmission of electromagnetic waves in the waveguide complies with physical laws.

[0049] Optionally, the model module 203 is configured to: The characteristic impedance is calculated by the width and height of the waveguide, the wave number of the operating frequency and the electromagnetic properties of the material to be measured; the phase constant is calculated by the size of the waveguide and the operating frequency, the attenuation constant is determined by the size of the waveguide, the operating frequency, the electromagnetic properties of the material to be measured and the roughness of the waveguide surface, and the propagation constant is determined based on the phase constant and the attenuation constant.

[0050] Optionally, the execution module 204 is configured to: Constructing voltage and current equations at a target location of the transmission line by using the voltage amplitude, propagation constant and characteristic impedance of the first electromagnetic wave signal and the second electromagnetic wave signal; The first relationship equation between S parameters and transmission line parameters is constructed by using load impedance, characteristic impedance, propagation constant and transmission line length; the second relationship equation between dielectric constant and propagation constant is constructed by using angular frequency and complex magnetic permeability; A set of equations is constructed by using the voltage and current equations, the first relationship equation and the second relationship equation, and the microwave dielectric constant is obtained by solving the set of equations by an iterative method.

[0051] Optionally, the system includes a formula module, wherein the formula module is configured to: The voltage and current equations at the target location of the transmission line are constructed using the following formulas: V(z)=V 0 + e -γz +V 0 - e γz Where V(z) and I(z) are the voltage and current at the target position z, respectively. 0 + and V 0 - are the voltage amplitudes of the first electromagnetic wave signal and the second electromagnetic wave signal, γ is the propagation constant, and Z 0 is the characteristic impedance, The first relationship equation between S parameters and transmission line parameters is constructed by the following formula: Where R is the reflection coefficient of the transmission line, T is the transmission coefficient of the transmission line, and Z L is the load impedance, d is the transmission line length, and the second relationship between the dielectric constant and the propagation constant is constructed by the following formula: Where ω is the angular frequency, α is the attenuation constant, β is the phase constant, j is the imaginary unit, ∈ is the dielectric constant, ∈0 is the dielectric constant of vacuum, μ 0 is the vacuum permeability, μ is the complex permeability, ∈ ′ is the real part of the dielectric constant, ∈ ″ is the imaginary part of the dielectric constant.

[0052] It should be noted that: when the device provided in the above embodiment realizes its function, only the division of the above functional modules is used as an example. In actual application, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the device and method embodiments provided in the above embodiment belong to the same concept, and the specific implementation process is detailed in the method embodiment, which will not be repeated here.

[0053] This embodiment also discloses an electronic device, referring to Figure 3 The electronic device may include: at least one processor 301 , at least one communication bus 302 , a user interface 303 , a network interface 304 , and at least one memory 305 .

[0054] The communication bus 302 is used to realize the connection and communication between these components.

[0055] The user interface 303 may include a display screen (Display) and a camera (Camera). The optional user interface 303 may also include a standard wired interface and a wireless interface.

[0056] The network interface 304 may optionally include a standard wired interface or a wireless interface (such as a WI-FI interface).

[0057] Among them, the processor 301 may include one or more processing cores. The processor 301 uses various interfaces and lines to connect various parts in the entire server, and executes various functions of the server and processes data by running or executing instructions, programs, code sets or instruction sets stored in the memory 305, and calling data stored in the memory 305. Optionally, the processor 301 can be implemented in at least one hardware form of digital signal processing (Digital Signal Processing, DSP), field programmable gate array (Field-Programmable Gate Array, FPGA), and programmable logic array (Programmable Logic Array, PLA). The processor 301 can integrate one or a combination of a central processing unit (Central Processing Unit, CPU), a graphics processing unit (Graphics Processing Unit, GPU) and a modem. Among them, the CPU mainly processes the operating system, user interface and application programs; the GPU is responsible for rendering and drawing the content to be displayed on the display screen; the modem is used to process wireless communications. It can be understood that the above-mentioned modem may not be integrated into the processor 301, and it can be implemented separately through a chip.

[0058] Among them, the memory 305 may include a random access memory (Random Access Memory, RAM) and may also include a read-only memory (Read-Only Memory). Optionally, the memory 305 includes a non-transitory computer-readable storage medium. The memory 305 can be used to store instructions, programs, codes, code sets or instruction sets. The memory 305 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as a touch function, a sound playback function, an image playback function, etc.), instructions for implementing the above-mentioned various method embodiments, etc.; the data storage area may store data involved in the above-mentioned various method embodiments, etc. The memory 305 may optionally be at least one storage device located away from the aforementioned processor 301. As Figure 3 As shown, the memory 305 as a computer storage medium may include an operating system, a network communication module, a user interface module, and an application program for the microwave dielectric constant measurement method.

[0059] exist Figure 3In the electronic device shown, the user interface 303 is mainly used to provide an input interface for the user and obtain data input by the user; and the processor 301 can be used to call the application program for measuring the microwave dielectric constant stored in the memory 305. When executed by one or more processors 301, the electronic device executes one or more methods in the above-mentioned embodiments.

[0060] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the order of the actions described, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required for the present application.

[0061] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0062] In the several embodiments provided in this application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are only schematic, such as the division of units, which is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some service interfaces, and the indirect coupling or communication connection of devices or units can be electrical or other forms.

[0063] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0064] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0065] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a memory 305 and includes several instructions for a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the various embodiments of the present application. The aforementioned memory 305 includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a magnetic disk or an optical disk.

[0066] The above is only an exemplary embodiment of the present disclosure and cannot be used to limit the scope of the present disclosure. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the disclosure of the specification, those skilled in the art will easily think of other embodiments of the present disclosure. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the technical field that are not recorded in the present disclosure. The description and examples are only regarded as exemplary, and the scope and spirit of the present disclosure are defined by the claims.

Claims

1. A method for measuring microwave dielectric constant, characterized in that: A measurement platform for microwave dielectric constant, wherein the measurement method comprises: The material to be tested is placed between the transmitting antenna and the receiving antenna, the incident angle is adjusted to a predetermined value, a signal source is set to transmit a first electromagnetic wave signal, and a second electromagnetic wave signal is received, wherein the second electromagnetic wave signal is an electromagnetic wave signal after the first electromagnetic wave signal passes through the material to be tested; Calculating an amplitude ratio of the first electromagnetic wave signal to the second electromagnetic wave signal, and calculating a phase difference between the first electromagnetic wave signal and the second electromagnetic wave signal; Constructing a waveguide transmission model according to the material to be tested, and calculating the characteristic impedance and propagation constant of the transmission line of the waveguide transmission model according to the size of the waveguide in the waveguide transmission model, the operating frequency and the thickness of the material to be tested; A set of equations is constructed according to the amplitude ratio, the phase difference, the characteristic impedance and the propagation constant, and the microwave dielectric constant is obtained by solving the equations.

2. The method for measuring the microwave dielectric constant according to claim 1, characterized in that: The calculating the amplitude ratio of the first electromagnetic wave signal to the second electromagnetic wave signal, and calculating the phase difference between the first electromagnetic wave signal and the second electromagnetic wave signal comprises: Calculating a root mean square value or a peak value of the first electromagnetic wave signal to obtain a first amplitude, calculating a root mean square value or a peak value of the second electromagnetic wave signal to obtain a second amplitude, and calculating a ratio of the second amplitude to the first amplitude to obtain an amplitude ratio; The difference between the second phase of the second electromagnetic wave signal and the first phase of the first electromagnetic wave is calculated, and the difference is unwrapped according to the history of phase change to obtain a phase difference.

3. The method for measuring the microwave dielectric constant according to claim 2, characterized in that: The constructing a set of equations according to the amplitude ratio, the phase difference, the characteristic impedance and the propagation constant and solving them to obtain the microwave dielectric constant further comprises: The attenuation of the electromagnetic wave in the material to be tested is obtained according to the amplitude ratio, and the attenuation coefficient is calculated according to the attenuation; the phase delay of the electromagnetic wave in the material to be tested is obtained according to the phase difference, and the phase constant is calculated according to the phase delay.

4. The method for measuring the microwave dielectric constant according to claim 1, characterized in that: The constructing of a waveguide transmission model according to the material to be tested comprises: Determine the size of the waveguide according to the shape, size and test requirements of the material to be tested, wherein the size includes length, width, height or diameter; Establishing a geometric model according to the size and the thickness of the material to be measured; The electromagnetic properties of the material to be tested are set in the geometric model, including relative dielectric constant, relative magnetic permeability and electrical conductivity; the boundary conditions of the waveguide are set, and the boundary conditions include the electrical conductivity of the metal wall and the conditions of a perfect electrical conductor or a perfect magnetic conductor, so as to ensure that the transmission of electromagnetic waves in the waveguide complies with physical laws.

5. The method for measuring microwave dielectric constant according to claim 4, characterized in that: The step of calculating the characteristic impedance and propagation constant of the transmission line of the waveguide transmission model according to the size of the waveguide in the waveguide transmission model, the operating frequency and the thickness of the material to be measured comprises: The characteristic impedance is calculated by the width and height of the waveguide, the wave number of the operating frequency and the electromagnetic properties of the material to be measured; the phase constant is calculated by the size of the waveguide and the operating frequency, the attenuation constant is determined by the size of the waveguide, the operating frequency, the electromagnetic properties of the material to be measured and the roughness of the waveguide surface, and the propagation constant is determined based on the phase constant and the attenuation constant.

6. The method for measuring microwave dielectric constant according to claim 1, characterized in that: The step of constructing a set of equations according to the amplitude ratio, the phase difference, the characteristic impedance and the propagation constant and solving the equations to obtain the microwave dielectric constant comprises: Constructing voltage and current equations at a target location of the transmission line by using the voltage amplitude, propagation constant and characteristic impedance of the first electromagnetic wave signal and the second electromagnetic wave signal; The first relationship equation between S parameters and transmission line parameters is constructed by using load impedance, characteristic impedance, propagation constant and transmission line length; the second relationship equation between dielectric constant and propagation constant is constructed by using angular frequency and complex magnetic permeability; A set of equations is constructed by using the voltage and current equations, the first relationship equation and the second relationship equation, and the microwave dielectric constant is obtained by solving the set of equations by an iterative method.

7. The method for measuring microwave dielectric constant according to claim 6, characterized in that: The method comprises: The voltage and current equations at the target location of the transmission line are constructed using the following formulas: V(z)=V0 + yes -γz +V0 - yes γz Where V(z) and I(z) are the voltage and current at the target position z, respectively. V0 + and V0 - are the voltage amplitudes of the first electromagnetic wave signal and the second electromagnetic wave signal, γ is the propagation constant, Z0 is the characteristic impedance, The first relationship equation between S parameters and transmission line parameters is constructed by the following formula: Where R is the reflection coefficient of the transmission line, T is the transmission coefficient of the transmission line, and Z L is the load impedance, d is the transmission line length, and the second relationship between the dielectric constant and the propagation constant is constructed by the following formula: Where ω is the angular frequency, α is the attenuation constant, β is the phase constant, j is the imaginary unit, ∈ is the dielectric constant, ∈0 is the vacuum dielectric constant, μ0 is the vacuum permeability, μ is the complex permeability, ∈ ′ is the real part of the dielectric constant, ∈ ″ is the imaginary part of the dielectric constant.

8. A microwave dielectric constant measurement system, characterized in that: It includes signal module, calculation module, model module and execution module, among which: A signal module is configured to place the material to be tested between the transmitting antenna and the receiving antenna, adjust the incident angle to a predetermined value, set the signal source to transmit a first electromagnetic wave signal, and receive a second electromagnetic wave signal, wherein the second electromagnetic wave signal is an electromagnetic wave signal after the first electromagnetic wave signal passes through the material to be tested; a calculation module, configured to calculate an amplitude ratio of the first electromagnetic wave signal and the second electromagnetic wave signal, and calculate a phase difference between the first electromagnetic wave signal and the second electromagnetic wave signal; A model module, configured to construct a waveguide transmission model according to the material to be tested, and calculate the characteristic impedance and propagation constant of the transmission line of the waveguide transmission model according to the size of the waveguide in the waveguide transmission model, the operating frequency and the thickness of the material to be tested; An execution module is configured to construct a set of equations according to the amplitude ratio, the phase difference, the characteristic impedance and the propagation constant and solve them to obtain the microwave dielectric constant.

9. An electronic device, characterized in that: It includes a processor, a memory, a user interface and a network interface, the memory is used to store instructions, the user interface and the network interface are both used to communicate with other devices, and the processor is used to execute the instructions stored in the memory so that the electronic device executes the method as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores instructions, and when the instructions are executed, the method according to any one of claims 1 to 7 is executed.

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