Integrated Piezoelectric Ceramic Size Design Method and System Based on Electromagnetic Interference Frequency

Abstract

This invention relates to the fields of electronic component design and electromagnetic compatibility (EMC) technology, specifically disclosing a method and system for designing the dimensions of integrated piezoelectric ceramics based on electromagnetic interference frequencies. The method and system of this invention measure and analyze the impedance amplitude-frequency characteristics of the piezoelectric ceramic, identify its resonant frequency, and establish an electromechanical coupling model and a frequency offset model of the piezoelectric ceramic under weak coupling conditions. Since the constructed model is associated with material parameters, geometric dimensions, and resonant frequencies, the center frequency of the target interference signal is used as the design input, allowing for the reverse calculation and determination of the optimal geometric dimensions of the integrated piezoelectric ceramic for multiple interference signals. This design method and system of this invention realizes the transformation of piezoelectric ceramic filters from "selection and adaptation" to "precise design," enabling customized design of integrated piezoelectric ceramic components for specific electromagnetic interference, achieving efficient customized design and performance improvement of filters.

Description

Technical Field

[0001] This invention relates to the field of piezoelectric ceramic element design and electromagnetic compatibility technology, specifically to a method and system for reverse design based on a target electromagnetic interference frequency to determine the optimal geometric dimensions of an integrated piezoelectric ceramic filter. Background Technology

[0002] Piezoelectric ceramic materials, with their unique resonant characteristics, exhibit extremely low impedance at specific frequencies and high impedance at the anti-resonance point, making them suitable for constructing solid-state filters with excellent frequency selectivity. Compared to traditional LC filters, piezoelectric ceramic filters offer advantages such as high quality factor, sharp frequency response, small size, low cost, and low insertion loss, and have gradually replaced traditional filter structures in numerous electronic circuits.

[0003] Based on the numerous advantages of piezoelectric ceramic filters, applying them to EMI (electromagnetic interference) suppression in power converters is expected to significantly reduce the size and weight of the filters while improving the power density and overall efficiency of the circuit system. This perfectly aligns with the dual requirements of high power density and high electromagnetic compatibility performance in consumer electronics. However, traditional design methods for using piezoelectric ceramic filters in electronic devices typically only employ monolithic piezoelectric ceramic designs. The resonant frequency of a monolithic piezoelectric ceramic is limited, which cannot meet the need to suppress more discrete interferences, especially in complex electromagnetic environments such as power sensors and communication equipment, where interference frequencies may be multiple and specific.

[0004] Therefore, designing a method that can actively and accurately design the dimensions of integrated piezoelectric ceramic core components based on multiple target interference frequencies, thereby optimizing filter performance, is of great significance to the technological development in this field. Summary of the Invention

[0005] The technical objective of this invention is to provide a method and system for designing the dimensions of integrated piezoelectric ceramics based on electromagnetic interference frequencies. This method or system can use multiple interference frequencies as direct input parameters and derive the optimal dimensions of the integrated piezoelectric ceramics by inversely using established frequency offset model parameters, thereby achieving efficient customized design and performance improvement of filters.

[0006] To achieve the aforementioned technical objectives, the present invention provides technical solutions from the following aspects.

[0007] In the following technical solution, the integrated piezoelectric ceramic comprises two piezoelectric ceramic units connected by an intermediate connecting bridge.

[0008] In a first aspect, the present invention provides a method for designing the dimensions of integrated piezoelectric ceramics based on electromagnetic interference frequency, characterized by comprising the following steps:

[0009] Step S1: Determine the parameters of the piezoelectric ceramic material, including bulk density, Poisson's ratio, and elastic compliance constant;

[0010] Step S2: The center frequencies of the two different electromagnetic interference signals acquired from the target scene... and As respectively Substituting into the theoretical resonant frequency formula (1), the two profile dimensions are obtained. and ;

[0011] (1);

[0012] In equation (1), This is the resonant frequency of the piezoelectric ceramic unit in monolithic mode. These are the outline dimensions of the piezoelectric ceramic unit. For bulk density, Poisson's ratio, The elastic compliance constant of the material;

[0013] right and Make fine adjustments separately, and compare the results before and after the adjustments. and The absolute value of the change is controlled between 0.001mm and 0.1mm; and Or after fine-tuning and The outline dimensions of the two piezoelectric ceramic units of the integrated piezoelectric ceramic are output.

[0014] Step S3: Obtain the fine-tuned and ;

[0015] by As After fine-tuning As l, after fine-tuning As l i Substituting into equation (2), we obtain equation one, which contains the values ​​W and K to be solved.

[0016] by As After fine-tuning As l, after fine-tuning As l i Substituting into equation (2), we obtain equation two, which contains the values ​​W and K to be solved.

[0017] (2);

[0018] in, Frequency offset coefficient:

[0019]

[0020] In formula (2):

[0021] l represents the current fine-tuned contour dimension of the piezoelectric ceramic unit;

[0022] l i The fine-tuned contour dimensions of another piezoelectric ceramic unit;

[0023] r0, r1, r2, r3, r4, a, c, o, p, q, h, m, n are the influencing factors;

[0024] T represents the thickness of the piezoelectric ceramic element, which is a set value;

[0025] W and K are the length and width of the intermediate connecting bridge, respectively, both in millimeters, and J = KW, CHA = KW - l1l2 = KW - l1 i ZE=ll i ;

[0026] By jointly solving equations one and two, we obtain W and K, which are then used as the length and width outputs of the intermediate connecting bridge.

[0027] Based on the above solutions, further improvements or preferred solutions include:

[0028] Furthermore, the method for determining the piezoelectric ceramic material parameters in step S1 includes the following sub-steps:

[0029] Step S11: Apply a frequency scanning signal to the pre-prepared square piezoelectric ceramic unit sample, measure and extract the impedance data of the sample profile vibration mode, and use the differential evolution algorithm to fit the extracted impedance data to obtain the electrical equivalent circuit RLC parameters of the sample at the resonant frequency.

[0030] Step S12: Based on the relationship between the RLC parameters of the electrical equivalent circuit and the material parameters of the sample at the resonant frequency, the actual material parameters of the piezoelectric ceramic are extracted.

[0031] Furthermore, step S12 describes the relationship between the RLC parameters and the material parameters using the following formula:

[0032] (3);

[0033] In formula (3):

[0034] ɛ0 is the vacuum permittivity;

[0035] It is the dielectric constant component under constant stress;

[0036] k p The electromechanical coupling coefficient;

[0037] l represents the outline dimension of the piezoelectric ceramic unit;

[0038] t is the thickness of the piezoelectric ceramic unit;

[0039] ρ is the bulk density;

[0040] σ E Poisson's ratio;

[0041] It is the elastic compliance constant;

[0042] Q m For mechanical quality factors;

[0043] This is the resonant frequency of the piezoelectric ceramic unit in monolithic mode.

[0044] Furthermore, the square piezoelectric ceramic unit sample uses PZT-5A piezoelectric ceramic.

[0045] Furthermore, The values ​​of each influencing factor in the expression are as follows:

[0046] r0 = 0.00126339905611663;

[0047] r1 = -1.50195667300665;

[0048] r2 = -0.0159810217951752;

[0049] r3 = -0.0230741621289602;

[0050] r4 = 0.0600098608839458;

[0051] a = 0.00627139456000456;

[0052] c = -12.1366545015332;

[0053] o = 1.03130722459673;

[0054] p = -0.0127546852583393;

[0055] q = 0.0144949768501495;

[0056] h = 0.11758126697714;

[0057] m = -0.101545827015298;

[0058] n = -0.0138157272079811.

[0059] Furthermore, in step S2, the center frequency f of the electromagnetic interference signal... EMI Determined in the following ways:

[0060] The collected time-domain interference signal is subjected to a fast Fourier transform to obtain its spectrum. The frequency corresponding to the peak with the largest amplitude in the spectrum is the center frequency.

[0061] Furthermore, the thickness T of the preset piezoelectric ceramic unit is 1 mm or less.

[0062] Furthermore, step S1 includes the extraction of material parameters, and the extraction process includes the following sub-steps:

[0063] Secondly, the present invention discloses an integrated piezoelectric ceramic dimensional design system based on electromagnetic interference frequency, used to implement the design method described in any of the preceding claims, characterized in that it includes:

[0064] The material parameter setting module allows you to select the material type and input pre-extracted material parameters.

[0065] Thickness setting module, used to set the thickness parameters of the piezoelectric ceramic unit;

[0066] The contour dimension calculation module is used to execute step S2 to obtain the contour dimensions of the two integrated piezoelectric ceramic units;

[0067] The intermediate connecting bridge size calculation module is used to execute step S3 to obtain the length and width of the intermediate connecting bridge.

[0068] Furthermore, the system designed in this invention also includes a center frequency extraction module for electromagnetic interference signals and a material parameter extraction module.

[0069] The center frequency extraction module is used to perform a fast Fourier transform on the acquired time-domain interference signal to obtain its spectrum, and to find the frequency corresponding to the peak with the largest amplitude in the spectrum, and output it as the center frequency of the interference signal.

[0070] The material parameter extraction module is used to execute step S1, which uses the sample impedance data obtained by frequency sweep measurement to perform parameter fitting on the obtained impedance data using the differential evolution algorithm to obtain the RLC parameters of the electrical equivalent circuit at the resonant frequency, and completes the extraction of material parameters based on the relationship between the RLC parameters and the piezoelectric ceramic material parameters.

[0071] Beneficial effects:

[0072] 1) The present invention is based on an integrated piezoelectric ceramic size design method and system based on electromagnetic interference frequency. It realizes the reverse precision design from interference frequency to component size, so that the resonant frequency of the filter with piezoelectric ceramic as the core component is highly matched with the interference frequency. It changes passive selection to active design and can customize the optimal solution of piezoelectric ceramic components for specific application scenarios, avoiding the compromise and additional tuning circuits of traditional methods.

[0073] 2) The design method and system of this invention overcome the limitations of traditional design methods and can be used to design integrated piezoelectric ceramics for suppressing the peak frequencies of multiple interference signals, thus helping to achieve efficient customized design and performance improvement of filters. Attached Figure Description

[0074] Figure 1 This is a flowchart of the design process of this invention; Figure 2 This is a schematic diagram showing the geometry and dimensional parameters of the integrated piezoelectric ceramic. Figure 3 The impedance amplitude-frequency characteristic curve of the integrated piezoelectric ceramic (a 10*10*1mm and a 4.9*4.9*1mm piezoelectric ceramic are weakly coupled through an intermediate connecting bridge with a width of 2.5mm and a length of 4mm) obtained in the actual test embodiment is used to verify the accuracy of the model. Detailed Implementation

[0075] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are not intended to limit the scope of protection of the present invention.

[0076] Option 1:

[0077] like Figure 1 As shown, this scheme is based on the integrated piezoelectric ceramic size design method according to electromagnetic interference frequency, and its implementation process is as follows:

[0078] Step S1: Determine the parameters of the piezoelectric ceramic material, including bulk density, Poisson's ratio, and elastic compliance constant.

[0079] The material parameters, such as bulk density, Poisson's ratio, and elastic compliance constant, can be obtained from information provided by the manufacturer or accurately measured using the following methods.

[0080] The specific measurement method is as follows:

[0081] Step S11: Apply a frequency scanning signal to the pre-prepared square piezoelectric ceramic unit sample, measure and extract the impedance data of the sample profile vibration mode, and use the differential evolution algorithm to fit the extracted impedance data to obtain the electrical equivalent circuit RLC parameters of the sample at the resonant frequency.

[0082] The equivalent impedance of the profile vibration mode (also known as the radial vibration mode) of the piezoelectric ceramic unit sample satisfies the following formula:

[0083]

[0084] In the above formula:

[0085] Z PZT This represents the impedance of the piezoelectric ceramic at the resonant point.

[0086] j is the imaginary unit;

[0087] ω is the angular frequency;

[0088] R m For series mechanical resistance;

[0089] C m It is a series mechanical capacitor;

[0090] L m For series mechanical inductance;

[0091] C0 is a parallel capacitor.

[0092] Step S12: Based on the relationship between the RLC parameters of the electrical equivalent circuit and the material parameters of each sample at the resonant frequency, the actual material parameters of the piezoelectric ceramic unit are extracted.

[0093] This invention describes the relationship between RLC parameters and material parameters using the following formula:

[0094] (3);

[0095] In formula (3):

[0096] ɛ0 is the vacuum permittivity;

[0097] It is the dielectric constant component under constant stress;

[0098] k p The electromechanical coupling coefficient;

[0099] l represents the outline dimension of the piezoelectric ceramic unit;

[0100] t is the thickness of the piezoelectric ceramic unit;

[0101] ρ is the bulk density;

[0102] σ E Poisson's ratio;

[0103] It is the elastic compliance constant;

[0104] Q m For mechanical quality factors;

[0105] This is the resonant frequency of the piezoelectric ceramic unit in monolithic mode.

[0106] Step S2: The center frequencies of the two different electromagnetic interference signals acquired from the target scene... and As respectively Substituting into the theoretical resonant frequency formula (1), the two profile dimensions are obtained. and ;

[0107] (1);

[0108] In equation (1), This is the resonant frequency of the piezoelectric ceramic unit in monolithic mode. These are the outline dimensions of the piezoelectric ceramic unit. For bulk density, Poisson's ratio, The elastic compliance constant of the material;

[0109] right and Fine-tuning is performed separately, for example, rounding to a certain decimal place based on manufacturing precision, and then comparing the values ​​before and after the fine-tuning. and The absolute value of the change was controlled between 0.001mm and 0.1mm; then, and Or after fine-tuning and The outline dimensions of the two piezoelectric ceramic units of the integrated piezoelectric ceramic are output.

[0110] Step S3: Obtain the fine-tuned and ;

[0111] by As After fine-tuning As l, after fine-tuning As l iSubstituting into equation (2), we obtain equation one, which contains the values ​​W and K to be solved.

[0112] by As After fine-tuning As l, after fine-tuning As l i Substituting into equation (2), we obtain equation two, which contains the values ​​W and K to be solved.

[0113] (2);

[0114] in, Frequency offset coefficient:

[0115]

[0116] In formula (2):

[0117] l represents the current fine-tuned contour dimension of the piezoelectric ceramic unit;

[0118] l i The fine-tuned contour dimensions of another piezoelectric ceramic unit;

[0119] r0, r1, r2, r3, r4, a, c, o, p, q, h, m, n are the influencing factors;

[0120] T is the thickness of the piezoelectric ceramic unit. To ignore the influence of thickness, T ≤ 1 mm.

[0121] W and K are the length and width of the intermediate connecting bridge, respectively, both in millimeters, and J = KW, CHA = KW - l1l2 = KW - l1 i ZE=ll i ;

[0122] By jointly solving equations one and two, we obtain W and K, which are then used as the length and width outputs of the intermediate connecting bridge.

[0123] In this step, the center frequency f of the electromagnetic interference signal is... EMI The acquisition can be determined in the following ways:

[0124] The collected time-domain interference signal is subjected to a fast Fourier transform to obtain its spectrum. The frequency corresponding to the peak with the largest amplitude in the spectrum is the center frequency.

[0125] Regarding the coefficient k 12 The values ​​of each influencing factor in the calculation formula are as follows: Based on the frequency model data of 1000 sets of piezoelectric ceramic samples with PZT-5A material, the influencing factors were calculated using the general DE optimization algorithm and are shown in the table below:

[0126] Table 1. Influence factors of PZT-5A resonant frequency model

[0127]

[0128] Example: Taking two specific electromagnetic interference peak frequencies of 170kHz and 345kHz as target resonant frequencies as examples, firstly, given that the resonant frequency model mainly relies on the contour vibration mode and the influence of thickness on the resonant frequency is negligible, the thickness of the piezoelectric ceramic is determined to be T=1mm to optimize the manufacturability of the device and achieve structural compactness. Then, the two target resonant frequencies are substituted into the theoretical resonant frequency formula for a single square piezoelectric ceramic, and the corresponding ideal contour lengths are calculated as follows: =10.004mm and =4.9265mm. Considering actual manufacturing precision and structural regularity, the above theoretical value is rounded down to the nearest integer. =10mm and =4.9mm; Finally, in order to accurately design the intermediate connecting bridge that connects the two resonant units and adjusts their coupling strength, the rounded and finely adjusted contour lengths were substituted into the geometric relationship based on the weak coupling resonant frequency offset model, and the key connecting bridge dimensions were obtained as K=2.5mm and W=4mm; Thus, all the dimensional parameters of the integrated piezoelectric ceramic were obtained, and the design of the main geometric dimensions of the integrated piezoelectric ceramic was completed.

[0129] Based on the above design, an integrated piezoelectric ceramic unit is obtained by weakly coupling a 10*10*1mm piezoelectric ceramic unit and a 4.9*4.9*1mm piezoelectric ceramic unit through an intermediate connecting bridge with a width of 2.5mm and a length of 4mm.

[0130] like Figure 3 The figure shows the measured impedance-amplitude frequency response curve of this integrated piezoelectric ceramic. Figure 3 As can be seen, the measured resonant frequency is very close to the predicted resonant frequency (electromagnetic interference spike frequency), which verifies the accuracy of the design method of this invention.

[0131] The above application examples provide a design method for integrated piezoelectric ceramics containing two different sizes of piezoelectric ceramic units. Similar design schemes can also be extended to integrated piezoelectric ceramic designs containing more units.

[0132] Option 2:

[0133] Based on the same design concept, this solution provides an integrated piezoelectric ceramic dimensional design system based on electromagnetic interference frequency, which can be used to implement the design method described in Solution 1.

[0134] This system design includes the following components:

[0135] 1) Material parameter extraction module, used to execute step S1, obtain sample impedance data through frequency sweep measurement, use differential evolution algorithm to fit parameters of the obtained impedance data to obtain RLC parameters of electrical equivalent circuit at resonant frequency, and extract material parameters based on the relationship between the RLC parameters and piezoelectric ceramic material parameters;

[0136] 2) Material parameter setting module: Select the material type and input the pre-extracted material parameters;

[0137] 3) Thickness setting module, used to set the thickness parameters of the piezoelectric ceramic unit;

[0138] 4) Contour dimension calculation module, used to execute step S2 to obtain the contour dimensions of the two integrated piezoelectric ceramic units;

[0139] 5) Intermediate connecting bridge size calculation module, used to execute step S3 to obtain the length and width of the intermediate connecting bridge;

[0140] 6) The center frequency extraction module is used to perform a fast Fourier transform on the acquired time-domain interference signal to obtain its spectrum, and find the frequency corresponding to the peak with the largest amplitude in the spectrum, and output it as the center frequency of the interference signal.

[0141] This solution works in a similar way to Solution 1, and is an invention under the same general inventive concept. Its principle and specific implementation method can be referred to the explanation of Solution 1, and will not be repeated here.

[0142] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for designing the dimensions of an integrated piezoelectric ceramic based on electromagnetic interference frequency, wherein the integrated piezoelectric ceramic comprises two piezoelectric ceramic units connected by an intermediate connecting bridge, characterized in that, Includes the following steps: Step S1: Determine the parameters of the piezoelectric ceramic material, including bulk density, Poisson's ratio, and elastic compliance constant; Step S2: The center frequencies of the two different electromagnetic interference signals acquired from the target scene... and As respectively Substituting into the theoretical resonant frequency formula (1), we obtain two profile dimensions, which we assume to be... and ; （1） In equation (1), This is the resonant frequency of the piezoelectric ceramic unit in monolithic mode. These are the outline dimensions of the piezoelectric ceramic unit. For bulk density, Poisson's ratio, The elastic compliance constant of the material; right and Make fine adjustments separately, and compare the results before and after the adjustments. and The absolute values ​​of the changes were all controlled between 0.001mm and 0.1mm; and Or after fine-tuning and The outline dimensions of the two piezoelectric ceramic units of the integrated piezoelectric ceramic are output. Step S3: Obtain the fine-tuned and ; by As After fine-tuning As l, after fine-tuning As l i Substituting into equation (2), we obtain equation one, which contains the values ​​W and K to be solved. by As After fine-tuning As l, after fine-tuning As l i Substituting into equation (2), we obtain equation two, which contains the values ​​W and K to be solved. （2） in, Frequency offset coefficient: In formula (2): l represents the current fine-tuned contour dimension of the piezoelectric ceramic unit; l i The fine-tuned contour dimensions of another piezoelectric ceramic unit; r0, r1, r2, r3, r4, a, c, o, p, q, h, m, n are the influencing factors; T represents the thickness of the piezoelectric ceramic element, which is a set value; W and K are the length and width of the intermediate connecting bridge, respectively, both in millimeters, and J = KW, CHA = KW - l1l2 = KW - l1 i ZE=ll i ; By jointly solving equations one and two, we obtain W and K, which are then used as the length and width outputs of the intermediate connecting bridge.

2. The method for designing the dimensions of integrated piezoelectric ceramics based on electromagnetic interference frequency as described in claim 1, characterized in that, Step S1, which determines the parameters of the piezoelectric ceramic material, includes the following sub-steps: Step S11: Apply a frequency scanning signal to the pre-prepared square piezoelectric ceramic unit sample, measure and extract the impedance data of the sample profile vibration mode, and use the differential evolution algorithm to fit the extracted impedance data to obtain the electrical equivalent circuit RLC parameters of the sample at the resonant frequency. Step S12: Based on the relationship between the RLC parameters of the electrical equivalent circuit and the material parameters of the sample at the resonant frequency, the actual material parameters of the piezoelectric ceramic are extracted.

3. The method for designing the dimensions of integrated piezoelectric ceramics based on electromagnetic interference frequency as described in claim 2, characterized in that, Step S12 describes the relationship between RLC parameters and material parameters using the following formula: （3） In formula (3): ɛ0 is the vacuum permittivity; It is the dielectric constant component under constant stress; k p The electromechanical coupling coefficient; l represents the outline dimension of the piezoelectric ceramic unit; t is the thickness of the piezoelectric ceramic unit; ρ is the bulk density; σ E Poisson's ratio; It is the elastic compliance constant; Q m For mechanical quality factors; This is the resonant frequency of the piezoelectric ceramic unit in monolithic mode.

4. The method for designing the dimensions of integrated piezoelectric ceramics based on electromagnetic interference frequency as described in claim 1, characterized in that, The integrated piezoelectric ceramic is PZT-5A piezoelectric ceramic.

5. The method for designing the dimensions of integrated piezoelectric ceramics based on electromagnetic interference frequency as described in claim 3, characterized in that, The values ​​of each influencing factor in the expression are as follows: r0= 0.00126339905611663； r1= -1.50195667300665； r2= -0.0159810217951752； r3= -0.0230741621289602； r4= 0.0600098608839458； a = 0.00627139456000456； c = -12.1366545015332； o = 1.03130722459673； p = -0.0127546852583393； q = 0.0144949768501495； h = 0.11758126697714； m = -0.101545827015298； n = -0.0138157272079811。 6. The method for designing the dimensions of integrated piezoelectric ceramics based on electromagnetic interference frequency as described in claim 1, characterized in that, In step S2, the center frequency f of the electromagnetic interference signal EMI Determined in the following ways: The collected time-domain interference signal is subjected to a fast Fourier transform to obtain its spectrum. The frequency corresponding to the peak with the largest amplitude in the spectrum is the center frequency.

7. The method for designing the dimensions of integrated piezoelectric ceramics based on electromagnetic interference frequency as described in claim 1, characterized in that, The thickness T of the piezoelectric ceramic unit is 1 mm or less.

8. An integrated piezoelectric ceramic dimensional design system based on electromagnetic interference frequency, used to implement the design method as described in any one of claims 1-7, characterized in that, include: The material parameter setting module allows you to select the material type and input pre-extracted material parameters. Thickness setting module, used to set the thickness parameters of the piezoelectric ceramic unit; The contour dimension calculation module is used to execute step S2 to obtain the contour dimensions of the two integrated piezoelectric ceramic units; The intermediate connecting bridge size calculation module is used to execute step S3 to obtain the length and width of the intermediate connecting bridge.

9. The integrated piezoelectric ceramic dimensional design system based on electromagnetic interference frequency as described in claim 8, characterized in that, It also includes a center frequency extraction module for electromagnetic interference signals; The center frequency extraction module is used to perform a fast Fourier transform on the acquired time-domain interference signal to obtain its spectrum, and to find the frequency corresponding to the peak with the largest amplitude in the spectrum, and output it as the center frequency of the interference signal.

10. The integrated piezoelectric ceramic dimensional design system based on electromagnetic interference frequency as described in claim 8, characterized in that, It also includes a material parameter extraction module; The material parameter extraction module is used to execute step S1, which uses the sample impedance data obtained by frequency sweep measurement to perform parameter fitting on the obtained impedance data using the differential evolution algorithm to obtain the RLC parameters of the electrical equivalent circuit at the resonant frequency, and completes the extraction of material parameters based on the relationship between the RLC parameters and the piezoelectric ceramic material parameters.

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