Multi-mode COM model structure

Abstract

The invention discloses a multi-mode COM (Component Object Model) model structure, which comprises a main mode fitting module and a high-order stray mode fitting module, and is characterized in that the main mode fitting module is used for fitting and outputting main modes of resonators and body wave weak coupling nearby the main modes; and the high-order stray mode fitting module is used for fitting and outputting each high-order stray mode of the resonator. According to the invention, the main mode fitting module and the high-order stray mode fitting module are adopted to respectively fit the main mode of the resonator, the body wave weak coupling near the main mode and each high-order stray mode, and the impedance curve or admittance curve of the model can be very close to the impedance curve or admittance curve of the resonator. And the method can be better used for the subsequent design of the SAW filter.

Description

Technical Field

[0001] The present invention belongs to the field of SAW filter design, and particularly relates to a multimodal COM model structure. Background Art

[0002] The coupled-mode (COM) model is widely used in the design of surface acoustic wave (SAW) filters and is usually used to fit the resonators in the filters. However, the traditional single-mode COM model can only fit the main mode of the resonator and the weak coupling of the bulk wave near it, and cannot fit the higher-order spurious modes. Please refer to Figure 1 and Figure 2 , in the actual design of acoustic filters, it is difficult to evaluate the stopband suppression at 1.5 times the frequency on the right side of the passband of the resonator by using the traditional single-mode COM model. Therefore, it is necessary to improve the traditional single-mode COM model to better fit the resonator. Summary of the Invention

[0003] Aiming at the deficiencies of the above-mentioned prior art, the technical problem to be solved by the present invention is to provide a multimodal COM model structure.

[0004] To solve the above technical problem, the present invention provides the following technical solutions:

[0005] A multimodal COM model structure includes

[0006] a main mode fitting module, which is used to fit the main mode of the resonator and the weak coupling of the bulk wave near it and output; and

[0007] a higher-order spurious mode fitting module, which is used to fit each higher-order spurious mode of the resonator separately and output.

[0008] Further, the main mode fitting module adopts a single-mode COM model.

[0009] Further, the method for fitting the main mode of the resonator and the weak coupling of the bulk wave near it by using a single-mode COM model includes:

[0010] Obtain the impedance curve or admittance curve of the resonator according to the measured data of the resonator;

[0011] Adjust the sound velocity of the single-mode COM model, and fit the frequency of the main mode in the impedance curve or admittance curve of the single-mode COM model with the frequency of the main mode in the impedance curve or admittance curve of the resonator;

[0012] Adjust the relative bandwidth of the single-mode COM model, so that the amplitude between the lowest point and the highest point of the main mode in the impedance curve or admittance curve of the single-mode COM model corresponds to the amplitude between the resonance frequency and the anti-resonance frequency of the main mode in the impedance curve or admittance curve of the resonator;

[0013] Adjust the dynamic resistance of the single-mode COM model so that the admittance value or impedance value at the resonance frequency of its main mode is the same as the admittance value or impedance value at the resonance frequency of the resonator's main mode;

[0014] Adjust the static capacitance and transmission loss of the single-mode COM model, and fit the anti-resonance frequency of the main mode in its impedance curve or admittance curve to the anti-resonance frequency of the main mode in the impedance curve or admittance curve of the resonator;

[0015] Adjust the reflection coefficient of the single-mode COM model, and fit the weak coupling of the bulk wave in the main mode and its vicinity in its impedance curve or admittance curve to the weak coupling of the bulk wave in the main mode and its vicinity in the impedance curve or admittance curve of the resonator.

[0016] Furthermore, the single-mode COM model includes a first interdigital transducer and two reflection grating devices symmetrically arranged on both sides of the first interdigital transducer, and a gap region is respectively formed between each reflection grating device and the first interdigital transducer.

[0017] Furthermore, the first interdigital transducer includes a first horizontal connecting grid, a second horizontal connecting grid arranged in parallel, and a plurality of first interdigital grids and a plurality of second interdigital grids uniformly arranged between the first horizontal connecting grid and the second horizontal connecting grid. The first interdigital grids and the second interdigital grids correspond one by one, and the corresponding first interdigital grids and second interdigital grids are staggered from each other to form an interdigital grid pair; the first end of the first interdigital grid is connected to the first horizontal connecting grid, and there is a gap between the second end of the first interdigital grid and the second horizontal connecting grid; there is a gap between the first end of the second interdigital grid and the first horizontal connecting grid, and the second end of the second interdigital grid is connected to the second horizontal connecting grid.

[0018] Furthermore, the reflection grating device includes a third horizontal connecting grid, a fourth horizontal connecting grid arranged in parallel, and a plurality of reflection gratings uniformly arranged between the third horizontal connecting grid and the fourth horizontal connecting grid. The first end of the reflection grating is connected to the third horizontal connecting grid, and the second end of the reflection grating is connected to the fourth horizontal connecting grid.

[0019] Furthermore, the high-order spurious mode fitting module includes a distal resonance unit and at least one proximal resonance unit, and the distal resonance unit and each proximal resonance unit are connected in parallel to the main mode fitting module; the distal resonance unit is used to fit the distal spurious mode of the resonator, and each proximal resonance unit is respectively used to fit a proximal spurious mode of the resonator.

[0020] Furthermore, the proximal resonance units all adopt the COM-E model, and the COM-E model includes a second interdigital transducer.

[0021] Further, the method for fitting the proximal spurious mode of the resonator using the COM-E model includes:

[0022] Adjust the sound velocity of the COM-E model, and fit the frequency of the main mode in the impedance curve or admittance curve of the COM-E model with the frequency of the proximal spurious mode of the resonator;

[0023] Adjust the relative bandwidth of the COM-E model so that the amplitude between the lowest point and the highest point of the main mode in the impedance curve or admittance curve of the COM-E model corresponds to the amplitude between the resonance frequency and the anti-resonance frequency of the proximal spurious mode in the impedance curve or admittance curve of the resonator;

[0024] Adjust the static capacitance and transmission loss of the COM-E model, and fit the anti-resonance frequency of the main mode in its impedance curve or admittance curve with the anti-resonance frequency of the proximal spurious mode in the impedance curve or admittance curve of the resonator;

[0025] Adjust the reflection coefficient of the COM-E model to move the position of the main mode in its impedance curve or admittance curve forward or backward to fit the position of the proximal spurious mode in the impedance curve or admittance curve of the resonator.

[0026] Further, the distal resonant unit adopts an RCL resonant branch, and the RCL resonant branch includes a resistor R, an inductor L, and a capacitor C connected in series; the calculation methods for the resistance value of the resistor R, the inductance of the inductor L, and the capacitance value of the capacitor C include:

[0027] Obtain the resonance frequency f ηr and the anti-resonance frequency f ηa ;

[0028] Calculate the capacitance value C η of the capacitor C, and the calculation formula is as follows:

[0029]

[0030] where Γ η represents the static capacitance ratio of the distal spurious mode; C0 represents the static capacitance of the single-mode COM model;

[0031] Calculate the resistance value R η of the resistor R, and the calculation formula is as follows:

[0032] R η =|Re(Z r η)-R p |

[0033] where Re(Z rη ) represents the real part value of the impedance at the resonance frequency of the distal spurious mode; Rp Represents the dynamic resistance of the single-mode COM model;

[0034] Calculate the inductance value L of the inductor L η , and the calculation formula is as follows:

[0035]

[0036] In the present invention, the main mode fitting module and the high-order spurious mode fitting module are respectively used to fit the main mode of the resonator, the weak coupling of the bulk wave near the main mode, and each high-order spurious mode. The impedance curve or admittance curve of the model can be very close to the impedance curve or admittance curve of the resonator. In addition, using the COM-E model to fit the proximal spurious mode will not introduce additional resistance and has no effect on the overall impedance value of the resonator, which can improve the accuracy of the model. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation of the present application. In the drawings:

[0038] Figure 1 It is a comparison diagram of the impedance curve of the traditional single-mode COM model and the impedance curve of the measured data of the resonator.

[0039] Figure 2 It is a comparison diagram of the real part curve of the impedance of the traditional single-mode COM model and the real part curve of the impedance of the measured data of the resonator.

[0040] Figure 3 It is a structural block diagram of an embodiment of the multi-mode COM model structure of the present invention.

[0041] Figure 4 It is a schematic structural diagram of the single-mode COM model.

[0042] Figure 5 It is the impedance curve of the resonator in a specific example.

[0043] Figure 6 It is the real part curve of the impedance of the resonator in a specific example.

[0044] Figure 7 It is a comparison diagram of the admittance curve of the single-mode COM model and the admittance curve of the resonator before adjusting the sound velocity of the single-mode COM model.

[0045] Figure 8 It is a comparison diagram of the admittance curve of the single-mode COM model and the admittance curve of the resonator before adjusting the relative bandwidth of the single-mode COM model.

[0046] Figure 9Comparison diagram of the admittance curves of the single-mode COM model and the resonator after adjusting the dynamic resistance of the single-mode COM model.

[0047] Figure 10 Comparison diagram of the admittance curves of the single-mode COM model and the resonator after adjusting the static capacitance and transmission loss of the single-mode COM model.

[0048] Figure 11 Comparison diagram of the admittance curves of the single-mode COM model and the resonator after adjusting the reflection coefficient of the single-mode COM model.

[0049] Figure 12 Comparison diagram of the impedance curves of the multi-mode COM model and the impedance curves of the measured data of the resonator.

[0050] Figure 13 Comparison diagram of the real part of the impedance curves of the multi-mode COM model and the real part of the impedance curves of the measured data of the resonator.

[0051] The reference numerals in the specification are as follows:

[0052] First interdigital transducer - 100; First horizontal connection grid - 111; First interdigital grid - 112; Second horizontal connection grid - 121; Second interdigital grid - 122; Reflection grid devices - 210, 220; Third horizontal connection grid - 211; Fourth horizontal connection grid - 212; Reflection grid - 213; Gap region - 300. Detailed implementation manners

[0053] The following illustrates the implementation manners of the present invention through specific specific examples. The diagrams provided in the following examples only schematically illustrate the basic concept of the present invention. Without conflict, the following examples and the features in the examples can be combined with each other.

[0054] Please refer to Figure 3 , Figure 3 which is a structural block diagram of an embodiment of the multi-mode COM model structure of the present invention. The multi-mode COM model structure of this embodiment includes a main mode fitting module and a high-order spurious mode fitting module. The main mode fitting module is used to fit and output the main mode of the resonator and the weak coupling of the bulk wave near it, and the high-order spurious mode fitting module is used to respectively fit and output each high-order spurious mode of the resonator.

[0055] Please refer to Figure 4, the main mode fitting module may adopt a single-mode COM model. The single-mode COM model includes a first interdigital transducer 100 (IDT) and two reflection grating devices symmetrically arranged on both sides of the first interdigital transducer 100, namely, a reflection grating device 210 and a reflection grating device 220. A gap region 300 is respectively formed between the reflection grating device 210 and the reflection grating device 220 and the first interdigital transducer 100.

[0056] The first interdigital transducer 100 includes a first horizontal connecting grid 111 and a second horizontal connecting grid 121 arranged in parallel, and a plurality of first interdigital grids 112 and a plurality of second interdigital grids 122 uniformly arranged between the first horizontal connecting grid 111 and the second horizontal connecting grid 121. The first interdigital grids 112 and the second interdigital grids 122 correspond one by one, and the corresponding first interdigital grids 112 and second interdigital grids 122 are staggered from each other to form an interdigital grid pair; the first end of the first interdigital grid 112 is connected to the first horizontal connecting grid 111, and there is a gap between the second end of the first interdigital grid 112 and the second horizontal connecting grid 121; there is a gap between the first end of the second interdigital grid 122 and the first horizontal connecting grid 111, and the second end of the second interdigital grid 122 is connected to the second horizontal connecting grid 121.

[0057] The reflection grating devices (210, 220) include a third horizontal connecting grid 211 and a fourth horizontal connecting grid 212 arranged in parallel, and a plurality of reflection gratings 213 uniformly arranged between the third horizontal connecting grid 211 and the fourth horizontal connecting grid 212. The first end of the reflection grating 213 is connected to the third horizontal connecting grid 211, and the second end of the reflection grating 213 is connected to the fourth horizontal connecting grid 212. Of course, Figure 4 It is only a schematic diagram. In an actual single-mode COM model, the number of the first interdigital grids 112 and the second interdigital grids 122 is generally more than 3, and the number of the reflection gratings 213 in the reflection grating device 210 and the reflection grating device 220 is generally also more than 3.

[0058] The single-mode COM model can fit the main mode resonance response and the weak coupling of the bulk wave slightly higher than the main mode response on the right because it has backscattering. The method for fitting the main mode of the resonator and the weak coupling of the bulk wave near it by using the single-mode COM model includes the following steps:

[0059] S101. Obtain its impedance curve or admittance curve according to the measured data of the resonator. Please refer to Figure 5 and Figure 6 , which are the impedance curve and the real part curve of the impedance of the resonator in a specific example.

[0060] S102. Please refer to Figure 7, adjust the sound velocity of the single-mode COM model, and fit the frequency of the main mode in the impedance curve or admittance curve of the single-mode COM model with the frequency of the main mode in the impedance curve or admittance curve of the resonator. The frequency of the main mode is determined according to the main mode resonance frequency ( Figure 7 the pointed downward part of the curve in Figure 7 ) and the main mode anti-resonance frequency ( Figure 7 the pointed upward part of the curve in

[0061] ). The higher the sound velocity of the single-mode COM model, the higher the frequency of its main mode. It can be clearly seen from Figure 8 that the frequency of the main mode in the admittance curve of the single-mode COM model before adjustment is significantly different from the frequency of the main mode in the admittance curve of the resonator. Therefore, it is necessary to fit by adjusting the sound velocity of the single-mode COM model. Figure 8

[0062] Figure 9

[0063] Figure 10

[0064] Figure 11

[0065] Figure 3 S103. Please refer to Figure 8 , adjust the relative bandwidth of the single-mode COM model so that the amplitude between the lowest point and the highest point of the main mode in the impedance curve or admittance curve of the single-mode COM model corresponds to the amplitude between the resonance frequency and the anti-resonance frequency of the main mode in the impedance curve or admittance curve of the resonator. It can be clearly seen from Figure 8 that the admittance values at the main mode resonance frequency and anti-resonance frequency of the single-mode COM model before adjustment are different from the admittance values at the main mode resonance frequency and anti-resonance frequency of the resonator. Therefore, it is necessary to fit by adjusting the relative bandwidth of the single-mode COM model.

[0062] S104. Please refer to Figure 9 , adjust the dynamic resistance of the single-mode COM model so that the admittance value or impedance value at the resonance frequency of its main mode is the same as the admittance value or impedance value at the resonance frequency of the main mode of the resonator.

[0063] S105. Please refer to Figure 10 , adjust the static capacitance and transmission loss of the single-mode COM model, and fit the anti-resonance frequency of the main mode in its impedance curve or admittance curve with the anti-resonance frequency of the main mode in the impedance curve or admittance curve of the resonator.

[0064] S106. Please refer to Figure 11 , adjust the reflection coefficient of the single-mode COM model, and fit the weak coupling of the bulk wave of the main mode and its vicinity in its impedance curve or admittance curve with the weak coupling of the bulk wave of the main mode and its vicinity in the impedance curve or admittance curve of the resonator. During this process, by adjusting the reflection coefficient, the frequency of the main mode in the impedance curve or admittance curve of the single-mode COM model will also be finely adjusted to remove the shift of the main mode frequency caused by adjusting the parameters of the single-mode COM model in steps S103 to S105.

[0065] Please continue to refer to Figure 3, the high-order spurious mode fitting module includes a distal resonator unit and at least one proximal resonator unit. The distal resonator unit and each proximal resonator unit are connected in parallel with the main mode fitting module. The distal resonator unit is used to fit the distal spurious mode of the resonator (i.e., the outermost high-order spurious mode). Each proximal resonator unit is respectively used to fit a proximal spurious mode of the resonator (i.e., a high-order spurious mode that is not the outermost one). Therefore, the number of proximal resonator units is the number of high-order spurious modes minus 1. Assume that there are η high-order spurious modes in the impedance curve or admittance curve of the resonator. Then the distal spurious mode is the ηth high-order spurious mode, and the other (η - 1) high-order spurious modes are all proximal spurious modes.

[0066] All the proximal resonator units adopt the COM-E model. The COM-E model includes a second interdigital transducer. The structure of the second interdigital transducer is the same as that of the first interdigital transducer 100, except for specific parameters. That is, the COM-E model is obtained by removing two reflection grating devices from the single-mode COM model. Each COM-E model is respectively used to fit a proximal spurious mode of the resonator. The method for fitting the proximal spurious mode of the resonator using the COM-E model includes the following steps:

[0067] S201. Adjust the sound velocity of the COM-E model to fit the frequency of the main mode in the impedance curve or admittance curve of the COM-E model with the frequency of this proximal spurious mode of the resonator.

[0068] S202. Adjust the relative bandwidth of the COM-E model so that the amplitude between the lowest point and the highest point of the main mode in the impedance curve or admittance curve of the COM-E model corresponds to the amplitude between the resonance frequency and the anti-resonance frequency of this proximal spurious mode in the impedance curve or admittance curve of the resonator.

[0069] S203. Adjust the static capacitance and transmission loss of the COM-E model to fit the anti-resonance frequency of the main mode in its impedance curve or admittance curve with the anti-resonance frequency of this proximal spurious mode in the impedance curve or admittance curve of the resonator.

[0070] S204. Adjust the reflection coefficient of the COM-E model to move the position of the main mode in its impedance curve or admittance curve forward or backward, so as to fit the position of this proximal spurious mode in the impedance curve or admittance curve of the resonator. Although the frequency of the main mode in the impedance curve or admittance curve of the COM-E model is fitted with the frequency of this proximal spurious mode of the resonator when adjusting the sound velocity, the position of the main mode in the impedance curve or admittance curve of the COM-E model will also change during the subsequent adjustment process. Therefore, the position of the main mode in the impedance curve or admittance curve of the COM-E model is adjusted again by the reflection coefficient of the COM-E model at the end.

[0071] The advantages of using the COM-E model to fit spurious modes are as follows: The fitting of spurious modes by the COM-E model is not affected by the static capacitance of the main mode, and at the same time, no additional resistance is introduced, which has no impact on the overall impedance value of the resonator; while when using the RCL resonance branch to fit spurious modes, an additional resistance value will be introduced, which has an impact on the total resistance of the resonator. If the RCL resonance branch is used to fit all spurious modes, the introduced resistance will increase the overall resistance of the resonator, resulting in a decrease in the accuracy of the model. Therefore, only one RCL resonance branch is introduced for fitting the far-end spurious modes to reduce the computational complexity of the model, and the remaining spurious modes are all fitted using the COM-E model.

[0072] The far-end resonance unit adopts an RCL resonance branch, and the RCL resonance branch includes a resistor R, an inductor L, and a capacitor C connected in series; the calculation methods for the resistance value of the resistor R, the inductance of the inductor L, and the capacitance value of the capacitor C include the following steps:

[0073] S301. Obtain the resonance frequency f of the far-end spurious mode according to the impedance curve or admittance curve of the resonator (i.e., measured data) ηr and the anti-resonance frequency f of the far-end spurious mode ηa .

[0074] S302. Calculate the capacitance value C of the capacitor C η , and the calculation formula is as follows:

[0075]

[0076] where Γ η represents the static capacitance ratio of the far-end spurious mode; C0 represents the static capacitance of the single-mode COM model.

[0077] S303. Calculate the resistance value R of the resistor R η , and the calculation formula is as follows:

[0078] Rη = ‖Re(Z r η)-R p |

[0079] where Re(Z rη ) represents the real part value of the impedance at the resonance frequency of the far-end spurious mode; R p represents the dynamic resistance of the single-mode COM model.

[0080] S304. Calculate the inductance L of the inductor L η , and the calculation formula is as follows:

[0081]

[0082] After adjusting the parameters of the single-mode COM model, each COM-E model, and the RCL resonant branch, the resonator model can be obtained by combining the single-mode COM model, each COM-E model, and the RCL resonant branch.

[0083] Please refer to Figure 12 and Figure 13 In this embodiment, since the multi-mode COM model structure respectively fits the main mode of the resonator, the weak coupling of the bulk wave near the main mode, and each high-order spurious mode through the single-mode COM model, each COM-E model, and the RCL resonant branch, the impedance curve or admittance curve of the multi-mode COM model is already very close to the impedance curve or admittance curve of the resonator. In addition, using the COM-E model to fit the proximal spurious mode will not introduce additional resistance and has no effect on the overall impedance value of the resonator, which can improve the accuracy of the model. Therefore, the multi-mode COM model structure of this embodiment can be preferably used for the subsequent design of SAW filters.

[0084] The above embodiments only represent the preferred implementation modes of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A multimodal COM model structure, characterized by: include A main mode fitting module, which is used to fit and output the main mode of the resonator and the weak coupling of the body waves near it; as well as The high-order spurious mode fitting module is used to fit and output each high-order spurious mode of the resonator.

2. The multimodal COM model structure according to claim 1, characterized in that: The main modal fitting module adopts a single-mode COM model.

3. The multimodal COM model structure as claimed in claim 2, characterized in that: Methods for fitting the main mode of the resonator and the weak coupling of the body waves near it using the single-mode COM model include: Obtaining the impedance curve or admittance curve of the resonator according to the measured data; Adjusting the sound velocity of the single-mode COM model, fitting the frequency of the main mode in the impedance curve or the admittance curve of the single-mode COM model with the frequency of the main mode in the impedance curve or the admittance curve of the resonator; Adjusting the relative bandwidth of the single-mode COM model so that the amplitude between the lowest point and the highest point of the main mode in the impedance curve or the admittance curve of the single-mode COM model corresponds to the amplitude between the resonant frequency and the anti-resonant frequency of the main mode in the impedance curve or the admittance curve of the resonator; Adjust the dynamic resistance of the single-mode COM model so that the admittance value or impedance value at the resonant frequency of its main mode is the same as the admittance value or impedance value at the resonant frequency of the main mode of the resonator; Adjust the static capacitance and transmission loss of the single-mode COM model, and fit the anti-resonance frequency of the main mode in its impedance curve or admittance curve with the anti-resonance frequency of the main mode in the impedance curve or admittance curve of the resonator; The reflection coefficient of the single-mode COM model is adjusted, and the weak coupling of the main mode and its vicinity in its impedance curve or admittance curve is fitted with the weak coupling of the main mode and its vicinity in the impedance curve or admittance curve of the resonator.

4. The multimodal COM model structure as claimed in claim 3, characterized in that: The single-mode COM model includes a first IDT and two reflection grating devices symmetrically arranged on both sides of the first IDT, and a gap area is formed between each of the reflection grating devices and the first IDT.

5. The multimodal COM model structure according to claim 4, characterized in that: The first interdigital transducer includes a first horizontal connecting grid and a second horizontal connecting grid arranged in parallel, and a plurality of first interdigital grids and a plurality of second interdigital grids uniformly arranged between the first horizontal connecting grid and the second horizontal connecting grid, the first interdigital grids and the second interdigital grids correspond to each other one by one, and the first interdigital grids and the second interdigital grids at corresponding positions are staggered to form an interdigital grid pair; the first end of the first interdigital grid is connected to the first horizontal connecting grid, and a gap is left between the second end of the first interdigital grid and the second horizontal connecting grid; the first end of the second interdigital grid is left with a gap between the first end of the second interdigital grid and the first horizontal connecting grid, and the second end of the second interdigital grid is connected to the second horizontal connecting grid.

6. The multimodal COM model structure according to claim 5, characterized in that: The reflective gate device includes a third horizontal connection gate and a fourth horizontal connection gate arranged in parallel, and a plurality of reflective gates uniformly arranged between the third horizontal connection gate and the fourth horizontal connection gate, wherein a first end of the reflective gate is connected to the third horizontal connection gate, and a second end of the reflective gate is connected to the fourth horizontal connection gate.

7. The multimodal COM model structure according to any one of claims 3 to 6, characterized in that: The high-order spurious mode fitting module includes a remote resonance unit and at least one proximal resonance unit, and the remote resonance unit and each proximal resonance unit are connected in parallel with the main mode fitting module; the remote resonance unit is used to fit the remote spurious mode of the resonator, and each proximal resonance unit is used to fit a proximal spurious mode of the resonator.

8. The multimodal COM model structure according to claim 7, characterized in that: The proximal resonant units all adopt a COM-E model, and the COM-E model includes a second interdigital transducer.

9. The multimodal COM model structure according to claim 8, characterized in that: The method of fitting the proximal spurious mode of the resonator using the COM-E model includes: The acoustic velocity of the COM-E model is adjusted, and the frequency of the main mode in the impedance curve or the admittance curve of the COM-E model is fitted with the frequency of the proximal stray mode of the resonator; The relative bandwidth of the COM-E model is adjusted so that the amplitude between the lowest point and the highest point of the main mode in the impedance curve or the admittance curve of the COM-E model corresponds to the amplitude between the resonant frequency and the anti-resonant frequency of the proximal spurious mode in the impedance curve or the admittance curve of the resonator; Adjust the static capacitance and transmission loss of the COM-E model, and fit the anti-resonance frequency of the main mode in its impedance curve or admittance curve with the anti-resonance frequency of the near-end spurious mode in the impedance curve or admittance curve of the resonator; The reflection coefficient of the COM-E model is adjusted so that the position of the main mode in its impedance curve or admittance curve moves forward or backward, and fits with the position of the proximal stray mode in the impedance curve or admittance curve of the resonator.

10. The multimodal COM model structure according to claim 7, characterized in that: The remote resonant unit adopts an RCL resonant branch, and the RCL resonant branch includes a resistor R, an inductor L and a capacitor C connected in series; the calculation method of the resistance value of the resistor R, the inductance of the inductor L and the capacitance value of the capacitor C includes: The resonant frequency f of the far-end spurious mode is obtained based on the measured data of the resonator. ηr and the anti-resonance frequency f ηa ; Calculate the capacitance C of capacitor C η , the calculation formula is as follows: Among them, Γ η Represents the static capacitance ratio of the far-end spurious mode; C0 represents the static capacitance of the single-mode COM model; Calculate the resistance value R of resistor R η , the calculation formula is as follows: R η =|Re(Z rη )-R p | Among them, Re(Z rη ) represents the real part of the impedance at the resonant frequency of the remote spurious mode; R p Represents the dynamic resistance of the single-mode COM model; Calculate the inductance L of the inductor L η , the calculation formula is as follows:

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