Finite element and MBVD model combined FBAR filter simulation method

Abstract

The invention discloses a finite element and MBVD model combined FBAR filter simulation method. The method comprises the following steps: S1, constructing a resonator three-dimensional finite element model; wherein the upper electrode layer and the lower electrode layer of the model are electrode layers with the same shape, and the electrode layers are pentagonal; s2, simulating the three-dimensional finite element model of the resonator to obtain an impedance-frequency characteristic curve; s3, adjusting the thickness of an upper electrode layer according to the impedance-frequency characteristic curve and a filter design target to obtain a three-dimensional finite element model of a target resonator; s4, establishing a corresponding MBVD model, and obtaining a first S parameter curve; s5, when the first S parameter curve meets a design target, establishing a three-dimensional finite element model of the filter; and if not, returning to S3. According to the method, the influence of the thickness and shape of the electrode and parasitic vibration on the resonant frequency can be accurately reflected, the parasitic vibration mode can be effectively inhibited, and the method has relatively high design efficiency, simulation precision and flexibility.

Description

Technical Field

[0001] The invention belongs to the field of filter design, and in particular relates to a FBAR filter simulation method combining a finite element and an MBVD model. Background Art

[0002] Film Bulk Acoustic Resonator (FBAR) is a radio frequency component based on the principle of acoustic wave resonance. Due to its small size and superior performance, it is widely used in radio frequency filters, oscillators and wireless communications. Compared with surface acoustic wave filters, FBAR has a higher operating frequency, smaller package size and higher Q value, especially in high-frequency communication fields (such as 5G, Wi-Fi). FBAR generates acoustic wave vibrations under the action of an electric field through piezoelectric materials (such as aluminum nitride AlN or lithium niobate LiNbO3). The sound waves propagate and reflect in the thin film of the piezoelectric material to form standing waves. The resonant frequency is closely related to the thickness of the film and the sound velocity of the material. The typical FBAR structure includes two upper and lower electrodes and a piezoelectric film sandwiched in the middle. When an external voltage is applied, the piezoelectric material undergoes mechanical deformation and excites sound waves due to the inverse piezoelectric effect. By designing the thickness of the electrodes and piezoelectric materials, the resonant frequency of the FBAR can be precisely controlled to meet the requirements of different frequency bands in radio frequency communications.

[0003] At present, the design of FBAR filters mostly relies on first establishing an equivalent circuit model and then using circuit simulation software to simulate the equivalent circuit in series and parallel. However, the equivalent circuit method may ignore some subtle effects in the three-dimensional structure, resulting in design errors. Although the finite element method is accurate, the overly large three-dimensional model will lead to a long simulation time. Using only the finite element method for design analysis will increase the design cycle of the filter. Summary of the invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides a FBAR filter simulation method combining finite element and MBVD models.

[0005] The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0006] In a first aspect, the present invention provides a FBAR filter simulation method combining a finite element and an MBVD model, the method comprising:

[0007] S1. Constructing a three-dimensional finite element model of a resonator; wherein the three-dimensional finite element model of the resonator comprises an upper electrode layer, a piezoelectric layer, a lower electrode layer, a support layer and a substrate layer arranged in sequence from top to bottom; the upper electrode layer and the lower electrode layer are electrode layers of the same shape, and the shape of the electrode layer is a pentagon;

[0008] S2. Simulating the three-dimensional finite element model of the resonator to obtain an impedance-frequency characteristic curve of the three-dimensional finite element model of the resonator;

[0009] S3, adjusting the thickness of the upper electrode layer according to the impedance-frequency characteristic curve and the filter design target, to obtain a three-dimensional finite element model of the target resonator;

[0010] S4, establishing an MBVD model of the three-dimensional finite element model of the target resonator, and obtaining a first S parameter curve according to the MBVD model;

[0011] S5. When the first S parameter curve meets the design target, a three-dimensional finite element model of the filter is established according to the three-dimensional finite element model of the target resonator; if not, return to S3 until the first S parameter curve meets the filter design target.

[0012] Optionally, before S1, the method further includes:

[0013] Constructing a plurality of initial resonator three-dimensional finite element models with electrode layers in the shape of square, circle, ellipse and pentagon;

[0014] Simulating the multiple initial resonator three-dimensional finite element models to obtain multiple impedance-frequency characteristic curves corresponding to the multiple initial resonator three-dimensional finite element models;

[0015] According to the multiple impedance-frequency characteristic curves, the shapes of the upper electrode layer and the lower electrode layer corresponding to the target impedance-frequency characteristic curve with the smallest parasitic resonance are determined to be completely identical pentagons, so that the shape of the electrode layer of the three-dimensional finite element model of the resonator is designed to be a pentagon.

[0016] Optionally, the three-dimensional finite element model of the resonator further includes: a perfect matching layer arranged outside the support layer and the substrate layer.

[0017] Optionally, before S2, the method further includes:

[0018] The upper electrode layer, piezoelectric layer, lower electrode layer, support layer and substrate layer in the three-dimensional finite element model of the resonator are meshed by free quadrilateral meshing and scanning; wherein the piezoelectric layer is divided into 3-5 layers, the perfectly matched layer is divided into 5-8 layers, and the upper electrode layer, the lower electrode layer, the support layer and the substrate layer are all divided into 3 layers.

[0019] Optionally, the filter three-dimensional finite element model includes four identical three-dimensional finite element models of target resonators connected in series and four identical three-dimensional finite element models of target resonators connected in parallel.

[0020] Optionally, after S5, the method further includes:

[0021] Simulating the three-dimensional finite element model of the filter to obtain a second S parameter curve of the three-dimensional finite element model of the filter;

[0022] The first S parameter curve and the second S parameter curve are compared to obtain a simulation result of the three-dimensional finite element model of the filter.

[0023] Optionally, the material of the upper electrode layer and the lower electrode layer is Mo.

[0024] Optionally, the material of the piezoelectric layer is AlN.

[0025] Optionally, the material of the support layer is SiO2.

[0026] Optionally, the material of the substrate layer is Si.

[0027] The technical solution provided by the embodiments of the present invention may have the following beneficial effects:

[0028] In the above technical solution, the simulation analysis of the FBAR filter can more accurately reflect the influence of electrode thickness, shape and parasitic vibration on the resonant frequency, avoiding the simplification error of the equivalent circuit model. The parasitic vibration mode is effectively suppressed by the pentagonal electrode layer, and the small peaks and noise in the frequency response are reduced, thereby improving the selectivity of the filter. In addition, the present invention first uses the MBVD model for rough simulation, optimizes the three-dimensional model parameters of a single resonator, and then establishes a three-dimensional finite element model of the filter after the performance meets the target, so as to obtain more accurate simulation results. This simulation method avoids the problem of long calculation time caused by directly adjusting the model parameters of the filter, significantly improves the design efficiency, and maintains the high precision and optimization flexibility of the simulation.

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a flow chart of a FBAR filter simulation method combining finite element and MBVD model provided by an embodiment of the present invention;

[0031] Figure 2 is a schematic structural diagram of a three-dimensional finite element model of a resonator provided by an embodiment of the present invention;

[0032] Figure 3 is a schematic diagram of a perfect matching layer provided by an embodiment of the present invention;

[0033] Figure 4is a schematic diagram of an impedance-frequency characteristic curve of a three-dimensional finite element model of a resonator provided by an embodiment of the present invention;

[0034] Figure 5 is a schematic diagram of a three-dimensional finite element model of a resonator after meshing provided by an embodiment of the present invention;

[0035] Figure 6 is a schematic diagram of an MBVD model of a three-dimensional finite element model of a resonator provided in an embodiment of the present invention;

[0036] Figure 7 is a schematic diagram of a simulated impedance-frequency characteristic curve provided by an embodiment of the present invention;

[0037] Figure 8 is a schematic structural diagram of a three-dimensional finite element model of a filter provided by an embodiment of the present invention;

[0038] Fig. 9 is a schematic diagram of a filter topology structure provided by an embodiment of the present invention;

[0039] Fig.10 It is a comparative schematic diagram of an S parameter curve provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to facilitate the understanding of the scheme of the present invention, the relevant state of the prior art and the inventive concept of the present invention are first briefly described.

[0041] Most existing FBAR filter designs rely on equivalent circuit models of resonators, such as the Modified Butterworth-Van Dyke (MBVD) model and the Mason model. However, the equivalent circuit model is a simplification of the three-dimensional physical structure and cannot accurately reflect the impact of electrode thickness, shape, and parasitic vibration modes on the actual frequency response. This simplification leads to the neglect of some important details in the design, and its performance cannot be truly simulated, let alone optimized for parasitic resonance. In traditional designs, due to unreasonable electrode geometry design, parasitic vibration modes (such as Lamb waves) are easily generated. These vibration modes will cause small peaks or noise in the frequency response, thereby affecting the selectivity and signal quality of the filter.

[0042] Therefore, the present invention proposes a FBAR filter simulation method combining finite element and MBVD model to solve the technical problem.

[0043] Figure 1 FIG. 1 is a flow chart of a FBAR filter simulation method combining finite element and MBVD models provided in an embodiment of the present invention. Figure 1 As shown, the method comprises the following steps:

[0044] S1. Construct a three-dimensional finite element model of a resonator; wherein the three-dimensional finite element model of the resonator includes an upper electrode layer, a piezoelectric layer, a lower electrode layer, a support layer and a substrate layer arranged in sequence from top to bottom; the upper electrode layer and the lower electrode layer are electrode layers of the same shape, and the shape of the electrode layer is a pentagon.

[0045] It can be understood that when using COMSOL to construct a three-dimensional finite element model of the resonator, the thickness of each layer is determined according to the actual performance requirements. As the thickness increases, the resonant frequency will gradually decrease. The thickness of the substrate layer can be 5um, the support layer can be 0.33um, the lower electrode layer can be 0.2um, the piezoelectric layer can be 0.5um, and the thickness of the upper electrode layer can be adjusted.

[0046] In one embodiment, Figure 2 is a schematic structural diagram of a three-dimensional finite element model of a resonator provided by an embodiment of the present invention, Figure 2 The three-dimensional finite element model of the resonator shown may include, arranged from top to bottom, an upper electrode layer 1, a piezoelectric layer 2, a lower electrode layer 3, a support layer 4, an air cavity 5, and a substrate layer 6. The air cavity 5 is a hollow area between the support layer 4 and the substrate layer 6.

[0047] Optionally, before S1, the method may further include:

[0048] Constructing a plurality of initial resonator three-dimensional finite element models with electrode layers in the shape of square, circle, ellipse and pentagon;

[0049] Simulating a plurality of initial resonator three-dimensional finite element models to obtain a plurality of impedance-frequency characteristic curves corresponding to the plurality of initial resonator three-dimensional finite element models;

[0050] According to a plurality of impedance-frequency characteristic curves, it is determined that the shapes of the upper electrode layer and the lower electrode layer corresponding to the target impedance-frequency characteristic curve with the minimum parasitic resonance are completely identical pentagons, so that the shape of the electrode layer of the three-dimensional finite element model of the resonator is designed to be a pentagon.

[0051] It is understandable that electrode layers of different shapes can be designed to obtain the optimal shape that can suppress parasitic resonance; in the present invention, the shape of the electrode layer is set to square, circle, ellipse and pentagon, respectively. Furthermore, the electrode layer can also be designed to be other shapes, such as triangle, diamond, etc., and the present invention is not limited here.

[0052] Optionally, the material of the upper electrode layer and the lower electrode layer is Mo; the material of the piezoelectric layer is AlN; the material of the support layer is SiO2; and the material of the substrate layer is Si.

[0053] Optionally, Figure 3is a schematic diagram of a perfect matching layer provided by an embodiment of the present invention, such as Figure 3 As shown, the three-dimensional finite element model of the resonator also includes: a perfect matching layer arranged outside the support layer and the substrate layer; Figure 3 As shown, the perfectly matched layer is the blue area distributed around the outside of the support layer and the substrate layer.

[0054] S2. Simulate the three-dimensional finite element model of the resonator to obtain an impedance-frequency characteristic curve of the three-dimensional finite element model of the resonator.

[0055] Understandably, Figure 4 is a schematic diagram of an impedance-frequency characteristic curve of a three-dimensional finite element model of a resonator provided by an embodiment of the present invention, such as Figure 4 As shown, the figure shows the impedance-frequency characteristic curve of the three-dimensional finite element model of the resonator with a pentagonal electrode layer.

[0056] Optionally, before S2, the method may also include: using free quadrilateral meshing and scanning to mesh the upper electrode layer, piezoelectric layer, lower electrode layer, support layer and substrate layer in the three-dimensional finite element model of the resonator; wherein the number of division layers of the piezoelectric layer is 3-5 layers, the number of division layers of the perfect matching layer is 5-8 layers, and the number of division layers of the upper electrode layer, the lower electrode layer, the support layer and the substrate layer are all 3 layers.

[0057] Understandably, Figure 5 is a schematic diagram of a three-dimensional finite element model of a resonator after meshing provided by an embodiment of the present invention, such as Figure 5 As shown in the figure, the three-dimensional finite element model of the resonator is meshed. A mesh that is too fine will cause excessive resource usage and slow simulation speed; a mesh that is too coarse will cause a large deviation between the simulation results and the actual results. Therefore, different meshes should be divided differently for different parts of the three-dimensional finite element model of the resonator, and free quadrilateral meshes and sweeping methods are used for meshing.

[0058] It is worth mentioning that before simulating multiple initial resonator three-dimensional finite element models whose electrode layers are square, circular, elliptical and pentagonal, these initial resonator three-dimensional finite element models are also meshed.

[0059] S3. According to the impedance-frequency characteristic curve and the filter design target, the thickness of the upper electrode layer is adjusted to obtain a three-dimensional finite element model of the target resonator.

[0060] It can be understood that according to the impedance-frequency characteristic curve and the design objectives of the filter to be designed, the thickness of the upper electrode of the resonator is adjusted so that the impedance-frequency characteristic curve meets the required requirements and the parallel resonant frequency of the parallel resonator is equal to the series resonant frequency of the series resonator.

[0061] S4. Establishing an MBVD model of the three-dimensional finite element model of the target resonator, and obtaining a first S parameter curve according to the MBVD model.

[0062] Understandably, Figure 6 is a schematic diagram of an MBVD model of a three-dimensional finite element model of a resonator provided in an embodiment of the present invention. The circuit includes a resistor Rs, a resistor Rm, a resistor R0, a capacitor Cm, a capacitor C0 and an inductor Lm. Figure 7 is a schematic diagram of a simulated impedance-frequency characteristic curve provided by an embodiment of the present invention, such as Figure 7 As shown, the dotted curve is the characteristic curve of the three-dimensional finite element model of the resonator simulated by the MBVD model, and the blue curve is the characteristic curve of the three-dimensional finite element model of the resonator.

[0063] S5. When the first S parameter curve meets the design target, a three-dimensional finite element model of the filter is established according to the three-dimensional finite element model of the target resonator; if not, return to S3 until the first S parameter curve meets the filter design target.

[0064] It can be understood that it is necessary to observe whether the first S parameter curve meets the design target. If so, a three-dimensional finite element model of the filter is established. If not, return to S3 to continue adjusting the thickness of the upper electrode layer until the first S parameter curve meets the filter design target.

[0065] Optionally, after S5, the method may further include:

[0066] Simulating the three-dimensional finite element model of the filter to obtain a second S parameter curve of the three-dimensional finite element model of the filter;

[0067] The first S parameter curve is compared with the second S parameter curve to obtain a simulation result of the three-dimensional finite element model of the filter.

[0068] It can be understood that, based on the thickness and shape data of the three-dimensional finite element model of the resonator obtained by the previous simulation, a three-dimensional finite element model of the filter is established. Figure 8 is a schematic diagram of the structure of a three-dimensional finite element model of a filter provided by an embodiment of the present invention, such as Figure 8 As shown, the three-dimensional finite element model of the filter is obtained by connecting multiple three-dimensional finite element models of the target resonator, wherein the three-dimensional finite element models S1, S2, S3 and S4 of the target resonator are connected in series, and the three-dimensional finite element models P1, P2, P3 and P4 of the target resonator are connected in parallel.

[0069] Optionally, it is understood that Fig. 9It is a schematic diagram of a filter topology structure provided by an embodiment of the present invention. The filter three-dimensional finite element model includes four identical three-dimensional finite element models of target resonators connected in series and four identical three-dimensional finite element models of target resonators connected in parallel. Perfect matching layers are arranged around the filter three-dimensional finite element model, and fixed constraints are added to the substrate layer at the bottom.

[0070] Understandably, reference Fig. 9 ,according to Fig. 9 The connection method shown is used to establish the MBVD model of the filter in ADS, and the first S parameter curve corresponding to the three-dimensional finite element model of the filter is obtained by simulation. Figure 8 A terminal is added to the upper electrode layer of the target resonator three-dimensional finite element model S1, and is set to 1W power to represent the input end; a terminal is added to the upper electrode layer of the target resonator three-dimensional finite element model S4 and the target resonator three-dimensional finite element model P4, and is set to 0W power to represent the output end; the upper electrode layer of the target resonator three-dimensional finite element model P1 and the target resonator three-dimensional finite element model P3, and the lower electrode layer of the target resonator three-dimensional finite element model P2 and the target resonator three-dimensional finite element model P4 are set to grounding, and the lower electrode layer of the target resonator three-dimensional finite element model S1, the target resonator three-dimensional finite element model S2, and the target resonator three-dimensional finite element model P1, the upper electrode layer of the target resonator three-dimensional finite element model S2, the target resonator three-dimensional finite element model S3, and the target resonator three-dimensional finite element model P2, and the lower electrode layer of the target resonator three-dimensional finite element model S3, the target resonator three-dimensional finite element model S4, and the target resonator three-dimensional finite element model P3 are respectively set to three groups of floating potentials to represent mutual connection, and meshing is performed.

[0071] In addition, Fig.10 is a comparative schematic diagram of an S parameter curve provided by an embodiment of the present invention, such as Fig.10 As shown, a first S parameter curve (ADS) obtained according to the MBVD model and a second S parameter curve (COMSOL) obtained according to the three-dimensional finite element model of the filter are shown, indicating the accuracy of the simulation results of the three-dimensional finite element model of the filter of the present invention.

[0072] Through the above technical solution, compared with the method of extracting the equivalent circuit first and then performing circuit simulation, the present invention can take into account the parasitic resonance in the FBAR resonator, and the simulation accuracy is higher. The simplified error of the traditional equivalent circuit model is avoided, and the influence of the electrode shape, thickness and material properties on the performance of the FBAR filter can be captured more accurately; the three-dimensional finite element modeling method of the present invention makes the performance optimization of the filter more convenient. By adjusting the shape, structure and other parameters of the electrode of the resonator in COMSOL, the influence of these changes on the parasitic resonance and frequency response can be intuitively observed. Therefore, various electrode shapes and structural schemes can be quickly evaluated, and the structure with the best parasitic resonance suppression effect can be selected to optimize the performance of the filter; by optimizing the thickness of the upper electrode layer, the resonant frequency of the FBAR can be flexibly adjusted to achieve the desired target. This flexibility enables the FBAR filter to better adapt to the application requirements of different frequency bands and enhances the applicability of the design; by adjusting the three-dimensional finite element model of a single resonator and fitting it to the MBVD circuit model for performance adjustment, the problem of high computational complexity and long time caused by directly adjusting the three-dimensional model of the entire filter is avoided, thereby significantly improving the simulation efficiency.

[0073] It should be noted that the terms "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention.

[0074] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

[0075] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art can understand and implement other changes to the disclosed embodiments by viewing the drawings and the disclosed content. In the description of the present invention, the term "comprising" does not exclude other components or steps, "one" or "an" does not exclude multiple situations, and "multiple" means two or more, unless otherwise clearly and specifically limited. In addition, certain measures are recorded in different embodiments, but this does not mean that these measures cannot be combined to produce good results.

[0076] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0077] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0078] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0079] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A FBAR filter simulation method combining finite element and MBVD model, characterized in that: The method comprises: S1. Constructing a three-dimensional finite element model of a resonator; wherein the three-dimensional finite element model of the resonator comprises an upper electrode layer, a piezoelectric layer, a lower electrode layer, a support layer and a substrate layer arranged in sequence from top to bottom; the upper electrode layer and the lower electrode layer are electrode layers of the same shape, and the shape of the electrode layer is a pentagon; S2. Simulating the three-dimensional finite element model of the resonator to obtain an impedance-frequency characteristic curve of the three-dimensional finite element model of the resonator; S3, adjusting the thickness of the upper electrode layer according to the impedance-frequency characteristic curve and the filter design target, to obtain a three-dimensional finite element model of the target resonator; S4, establishing an MBVD model of the three-dimensional finite element model of the target resonator, and obtaining a first S parameter curve according to the MBVD model; S5. When the first S parameter curve meets the design target, a three-dimensional finite element model of the filter is established according to the three-dimensional finite element model of the target resonator; if not, return to S3 until the first S parameter curve meets the filter design target.

2. The FBAR filter simulation method combining finite element and MBVD model according to claim 1, characterized in that: Before S1, the method further includes: Constructing a plurality of initial resonator three-dimensional finite element models with electrode layers in the shape of square, circle, ellipse and pentagon; Simulating the multiple initial resonator three-dimensional finite element models to obtain multiple impedance-frequency characteristic curves corresponding to the multiple initial resonator three-dimensional finite element models; According to the multiple impedance-frequency characteristic curves, the shapes of the upper electrode layer and the lower electrode layer corresponding to the target impedance-frequency characteristic curve with the smallest parasitic resonance are determined to be completely identical pentagons, so that the shape of the electrode layer of the three-dimensional finite element model of the resonator is designed to be a pentagon.

3. The FBAR filter simulation method combining finite element and MBVD model according to claim 1, characterized in that: The three-dimensional finite element model of the resonator further includes a perfect matching layer arranged outside the support layer and the substrate layer.

4. The FBAR filter simulation method combining finite element and MBVD model according to claim 3 is characterized in that: Before S2, the method further includes: The upper electrode layer, piezoelectric layer, lower electrode layer, support layer and substrate layer in the three-dimensional finite element model of the resonator are meshed by free quadrilateral meshing and scanning; wherein the piezoelectric layer is divided into 3-5 layers, the perfectly matched layer is divided into 5-8 layers, and the upper electrode layer, the lower electrode layer, the support layer and the substrate layer are all divided into 3 layers.

5. The FBAR filter simulation method combining finite element and MBVD model according to claim 1, characterized in that: The filter three-dimensional finite element model includes four identical three-dimensional finite element models of target resonators connected in series and four identical three-dimensional finite element models of target resonators connected in parallel.

6. The FBAR filter simulation method combining finite element and MBVD model according to claim 1, characterized in that: After S5, the method further includes: Simulating the three-dimensional finite element model of the filter to obtain a second S parameter curve of the three-dimensional finite element model of the filter; The first S parameter curve and the second S parameter curve are compared to obtain a simulation result of the three-dimensional finite element model of the filter.

7. The FBAR filter simulation method combining finite element and MBVD model according to claim 1, characterized in that: The material of the upper electrode layer and the lower electrode layer is Mo.

8. The FBAR filter simulation method combining finite element and MBVD model according to claim 1, characterized in that: The material of the piezoelectric layer is AlN.

9. The FBAR filter simulation method combining finite element and MBVD model according to claim 1, characterized in that: The material of the support layer is SiO2.

10. The FBAR filter simulation method combining finite element and MBVD model according to claim 1, characterized in that: The material of the substrate layer is Si.

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