CN114647964A - Method for designing bulk acoustic wave resonator and filter - Google Patents

Abstract

The present disclosure provides methods of designing bulk acoustic wave resonators and filters. The method for designing the bulk acoustic wave resonator comprises the following steps: establishing a physical model of the first bulk acoustic wave resonator according to the structure of the first bulk acoustic wave resonator; repeatedly adjusting the material parameters of the first bulk acoustic resonator in an iterative manner so that the difference between the finite element simulation result of the physical model of the first bulk acoustic resonator and the measurement result of the first bulk acoustic resonator is within a predetermined range; verifying the adjusted material parameter using a second bulk acoustic resonator different from the first bulk acoustic resonator; and designing the bulk acoustic wave resonator based on the verified material parameters. Further, the method of designing a bulk filter according to the present disclosure includes designing a filter using the resonators designed by the above-described method. According to the design method of the bulk acoustic wave resonator and the filter, the design period can be shortened, and the design cost can be reduced.

Description

Method for designing bulk acoustic wave resonator and filter

Technical Field

The present disclosure relates to the field of electronic circuits, and in particular, to methods of designing bulk acoustic wave resonators and filters.

Background

Bulk Acoustic Wave (BAW) resonators play an important role in the fields of communications, sensors, and the like because they have the advantages of small size, high frequency, large power capacity, high sensitivity, and the like. At present, the volume acoustic wave resonator occupies a larger and larger share in the field of radio frequency front end, especially in the market of radio frequency filters, and has greater development advantages in the fields of biosensing, medical measurement and the like.

The filter as a core device of the radio frequency front end is of great significance to promote the development of a new generation of communication standard and the miniaturization and multi-functionalization of a personal mobile terminal, so that high requirements on the performance of the filter, such as low insertion loss, steep filtering curve, high isolation and smaller size, are put forward. A new generation of bulk acoustic wave resonator technology can effectively solve the above-mentioned problems. The filter prepared by using the film bulk acoustic resonator technology has a steeper filtering curve, lower insertion loss and excellent out-of-band rejection capability.

At present, bulk acoustic wave resonators and filters constructed from bulk acoustic wave resonators are generally designed using equivalent circuit models. However, this design method cannot represent the acoustic effect of the bulk acoustic wave resonator, and cannot represent the performance improvement caused by the optimization of the geometric structure of the bulk acoustic wave resonator, so that the performance of the resonator cannot be optimized. In addition, with the design method, during design, a flow sheet of the bulk acoustic wave resonator is required to be firstly carried out to obtain a measurement result, and then the measurement result is fitted by modifying equivalent circuit model parameters, so that the design of the bulk acoustic wave resonator and the filter is carried out. If the result of the tape-out does not reach the design requirement, the tape-out needs to be performed again, which prolongs the design period and increases the design cost.

Therefore, there is still a need in the art for a method of designing a bulk acoustic wave resonator and a filter that can shorten the design period and reduce the design cost.

Disclosure of Invention

The following presents a simplified summary of the disclosure in order to provide a basic understanding of some aspects of the disclosure. It should be understood, however, that this summary is not an exhaustive overview of the disclosure, nor is it intended to identify key or critical elements of the disclosure, nor is it intended to be used to limit the scope of the disclosure. This summary is provided merely for the purpose of presenting some of the inventive concepts related to the disclosure in a simplified form as a prelude to the more detailed description that is presented later.

An object of the present disclosure is to provide a method of designing a bulk acoustic wave resonator and a filter capable of shortening a design period and reducing design cost.

According to an aspect of the present disclosure, there is provided a method of designing a bulk acoustic wave resonator, including: establishing a physical model of the first bulk acoustic wave resonator according to the structure of the first bulk acoustic wave resonator; repeatedly adjusting the material parameters of the first bulk acoustic resonator in an iterative manner so that the difference between the finite element simulation result of the physical model of the first bulk acoustic resonator and the measurement result of the first bulk acoustic resonator is within a predetermined range; verifying the adjusted material parameter using a second bulk acoustic resonator different from the first bulk acoustic resonator; and designing the bulk acoustic wave resonator based on the verified material parameters.

According to an embodiment of the present disclosure, verifying the adjusted material parameter using the second bulk acoustic wave filter includes: establishing a physical model of the second bulk acoustic wave resonator according to the structure of the second bulk acoustic wave resonator; performing finite element simulation on the physical model of the second bulk acoustic wave resonator by using the adjusted material parameters, and comparing the simulation result with the measurement result of the second bulk acoustic wave resonator; if the difference between the simulation result and the measurement result of the second bulk acoustic resonator is within a predetermined range, the adjusted material parameter passes verification; and if the difference between the simulation result and the measurement result of the second bulk acoustic resonator is not within the predetermined range, readjusting the material parameter until the difference between the simulation result and the measurement result of the first bulk acoustic resonator and the second bulk acoustic resonator are both within the predetermined range.

According to an embodiment of the present disclosure, the second bulk acoustic wave filter includes two or more second bulk acoustic resonators different from each other, and the verifying the adjusted material parameter using the second bulk acoustic wave filter includes: respectively establishing physical models of the two or more second bulk acoustic wave resonators according to the structures of the two or more second bulk acoustic wave resonators; performing a finite element simulation on each of the physical models of the two or more second bulk acoustic resonators using the adjusted material parameters, comparing the simulation results with the measurement results of the corresponding second bulk acoustic resonator; if the difference between the simulation result and the measurement result of the two or more second bulk acoustic resonators is within a predetermined range, the adjusted material parameter is verified; and if the difference between the simulation result and the measurement result of any one of the two or more second bulk acoustic resonators is not within a predetermined range, readjusting the material parameter until the difference between the simulation result and the measurement result of the first bulk acoustic resonator and the two or more second bulk acoustic resonators is within the predetermined range.

According to an embodiment of the present disclosure, the material parameter includes at least one of a dielectric constant, an elastic stiffness constant, a piezoelectric stress constant, a density of the piezoelectric material, and a density of the electrode material of the bulk acoustic wave resonator.

According to the embodiment of the present disclosure, the structure of the acoustic wave resonator is determined according to the layout of the bulk acoustic wave resonator.

According to an embodiment of the present disclosure, parameters characterizing the loss of the piezoelectric material and/or the electrode material of the bulk acoustic wave resonator are also used in the finite element simulation process of the physical model of the bulk acoustic wave resonator.

According to an embodiment of the present disclosure, designing a bulk acoustic wave resonator based on verified material parameters includes: according to design requirements, the geometry of the bulk acoustic wave resonator is designed based on verified material parameters.

According to an embodiment of the present disclosure, the geometry of the bulk acoustic wave resonator comprises the electrode shape and/or the microstructure of the bulk acoustic wave resonator.

According to another aspect of the present disclosure, there is provided a method of designing a filter, including designing a bulk acoustic wave resonator using the method of designing according to the above aspect of the present disclosure; and designing a filter using the designed bulk acoustic wave resonator.

According to another aspect of the present disclosure, there is provided a method for designing a filter, including: establishing a physical model of the first bulk acoustic wave resonator and a physical model of a first filter formed by the first bulk acoustic wave resonator according to the structure of the first bulk acoustic wave resonator; repeatedly adjusting material parameters of the first bulk acoustic wave resonator in an iterative manner so that differences between finite element simulation results of physical models of the first bulk acoustic wave resonator and the first filter and measurement results of the first bulk acoustic wave resonator and the first filter are within predetermined ranges, respectively; verifying the adjusted material parameter using a second bulk acoustic resonator different from the first bulk acoustic resonator and/or a second filter different from the first filter; designing a bulk acoustic wave resonator based on the verified material parameters; and designing a filter using the designed bulk acoustic wave resonator.

According to an embodiment of the present disclosure, verifying the adjusted material parameter using a second bulk acoustic resonator different from the first bulk acoustic resonator and/or a second filter different from the first filter comprises: establishing a physical model of the second bulk acoustic wave resonator and a physical model of a second filter composed of the second bulk acoustic wave resonator according to the structure of the second bulk acoustic wave resonator; performing finite element simulation on the physical model of the second bulk acoustic wave resonator and/or the second filter by using the adjusted material parameters, and comparing the simulation result with the measurement result of the second bulk acoustic wave resonator and/or the second filter; if the difference between the simulation result and the measurement result of the second bulk acoustic resonator and/or the second filter is within a predetermined range, the adjusted material parameter passes verification; and if the difference between the simulation result and the measurement result of the second bulk acoustic wave resonator and/or the second filter is not within the predetermined range, readjusting the material parameter until the difference between the simulation result and the measurement result of the first bulk acoustic wave resonator and the second bulk acoustic wave resonator and/or the first filter and the second filter are within the predetermined range.

According to the embodiment of the present disclosure, the structure of the bulk acoustic wave resonator is determined according to the layout of the bulk acoustic wave resonator.

According to an embodiment of the present disclosure, the material parameter includes at least one of a dielectric constant, an elastic stiffness constant, a piezoelectric stress constant and density of a piezoelectric material of the bulk acoustic wave resonator, and a density of an electrode material.

According to an embodiment of the present disclosure, parameters characterizing the loss of the piezoelectric material and/or the electrode material of the bulk acoustic wave resonator are used in a finite element simulation process of a physical model of the bulk acoustic wave resonator.

According to an embodiment of the present disclosure, parameters characterizing passive elements in a filter are used during a finite element simulation of a physical model of the filter.

According to an embodiment of the present disclosure, the passive element includes an inductor and/or a capacitor.

According to another aspect of the present disclosure, there is provided a computer-readable storage medium having stored thereon a computer program which, when executed by a computer, implements a design method according to the above aspect of the present disclosure.

Drawings

The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated into and constitute a part of this specification. The drawings illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure.

Fig. 1 shows a flow chart of a method of designing a bulk acoustic wave resonator according to an embodiment of the present disclosure.

Figure 2 shows a schematic diagram of a physical model of a bulk acoustic wave resonator according to an embodiment of the present disclosure.

Fig. 3 shows a graph comparing simulation results and measurement results of a bulk acoustic wave resonator according to an embodiment of the present disclosure.

Fig. 4 shows a flow chart of a design method of a filter according to a first embodiment of the present disclosure.

Fig. 5 shows a flow chart of a method of designing a filter according to a second embodiment of the present disclosure.

Fig. 6 shows a schematic diagram of a physical model of a filter according to an embodiment of the present disclosure.

Fig. 7 shows a graph comparing simulation results and measurement results of a filter according to an embodiment of the present disclosure.

FIG. 8 shows a block diagram of a general-purpose machine that may be used to implement a design method according to an embodiment of the present disclosure.

Detailed Description

In this specification, it will also be understood that when an element is referred to as being "on," "connected to," or "coupled to" other elements relative to the other elements, such as on, "connected to," or "coupled to" the other elements, the one element may be directly on, connected or coupled to the one element, or an intervening third element may also be present. In contrast, when an element is referred to in this specification as being "directly on," "directly connected to," or "directly coupled to" other elements, relative to the other elements, there are no intervening elements provided therebetween.

The present disclosure now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments are shown. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Like numbers refer to like elements throughout. Also, in the drawings, the thickness, ratio and size of the components are exaggerated for clarity of illustration.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, "a," "an," "the," and "at least one" do not denote a limitation of quantity, but rather are intended to include both the singular and the plural, unless the context clearly dictates otherwise. For example, "an element" means the same as "at least one element" unless the context clearly dictates otherwise. "at least one of" should not be construed as limited to the quantity "one". "or" means "and/or". The term "and/or" includes any and all combinations of at least one of the associated listed items.

Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms defined in commonly used dictionaries should be interpreted as having the same meaning as is in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

The meaning of "comprising" or "comprises" indicates a property, a quantity, a step, an operation, an element, a component or a combination thereof, but does not exclude other properties, quantities, steps, operations, elements, components or combinations thereof.

Hereinafter, exemplary embodiments according to the present disclosure will be described with reference to the accompanying drawings.

Fig. 1 shows a flow diagram of a method 100 of designing a bulk acoustic wave resonator according to an embodiment of the present disclosure.

As shown in fig. 1, a method 100 for designing a bulk acoustic wave resonator according to an embodiment of the present disclosure includes the steps of:

s110: establishing a physical model of the first bulk acoustic wave resonator according to the structure of the first bulk acoustic wave resonator;

s120: repeatedly adjusting the material parameters of the first bulk acoustic resonator in an iterative manner so that the difference between the finite element simulation result of the physical model of the first bulk acoustic resonator and the measurement result of the first bulk acoustic resonator is within a predetermined range;

s130: verifying the adjusted material parameter using a second bulk acoustic resonator different from the first bulk acoustic resonator; and

s140: and designing the bulk acoustic wave resonator based on the verified material parameters.

According to an embodiment of the present disclosure, in step S110, the structure of the first bulk acoustic wave resonator may be determined according to the layout of the first bulk acoustic wave resonator. That is, in step S110, a physical model corresponding to the manufactured first bulk acoustic wave resonator may be established from, for example, the layout of the first bulk acoustic wave resonator.

Fig. 2 shows a schematic diagram of a physical model of a first bulk acoustic wave resonator according to an embodiment of the present disclosure, wherein a pentagonal pattern located at the center of fig. 2 represents the first bulk acoustic wave resonator.

Bulk acoustic wave resonators typically have a sandwich structure of a lower electrode, a piezoelectric layer and an upper electrode fabricated on a substrate, wherein the piezoelectric layer is made of a piezoelectric material with electromechanical transduction capability, such as AlN or doped AlN, for effecting transduction between acoustic signals (acoustic waves) and electrical signals. Since bulk acoustic wave resonators are known to the person skilled in the art, their details are not described in greater detail herein for the sake of brevity.

According to the embodiment of the present disclosure, in step S120, a physical model of the first bulk acoustic wave resonator is simulated by finite element analysis to obtain a simulation result.

Finite Element Analysis (FEA) is a method of simulating real physical systems, such as geometry and load conditions, by mathematical approximation. The method approaches an infinite unknown quantity by a finite number of unknowns using simple yet interacting elements (i.e., units). In particular, finite element analysis replaces complex problems with simpler problems and then solves them. The method considers the solution domain as consisting of a number of small interconnected subdomains called finite elements, assumes a suitable (simpler) approximate solution for each element, and derives the overall satisfaction conditions (e.g. structural equilibrium conditions) for solving the domain, thereby yielding a solution to the problem. Most practical problems are difficult to obtain accurate solutions, and finite elements not only have high calculation precision, but also can adapt to various complex shapes, so the method becomes an effective engineering analysis means. Since finite element analysis is known to the person skilled in the art, the details thereof will not be described in more detail herein for the sake of brevity.

According to the embodiment of the present disclosure, in step S120, an approximate adjustment range of the material parameter may be determined according to a theoretical formula for measuring the performance of the first bulk acoustic wave resonator, so as to determine an initial value of the material parameter. Subsequently, finite element simulation of the physical model of the first bulk acoustic wave resonator is performed based on the initial value of the material parameter, and the simulation result is compared with the measurement result, and then the material parameter of the first bulk acoustic wave resonator is adjusted by a method such as gradient descent according to the comparison result. Subsequently, finite element simulation of the physical model of the first bulk acoustic wave resonator is performed again based on the adjusted material parameters, and the updated simulation result is compared again with the measurement result. By adjusting the material parameters of the first bulk acoustic resonator in the iterative manner described above until the difference between the finite element simulation result of the physical model of the first bulk acoustic resonator and the measurement result of the first bulk acoustic resonator is within the predetermined range. It should be noted that the phrase "the difference between a and B is within a predetermined range" as referred to herein means that the percentage of the difference between a and B as compared to B is less than 10%. For example, in step S120, "the difference between the simulation result and the measurement result of the physical model of the first bulk acoustic wave resonator is within the predetermined range" means that the percentage of the difference between the simulation result and the measurement result of the first bulk acoustic wave resonator as compared to the measurement result is within 10%.

According to an embodiment of the present disclosure, the adjusted material parameter of the first bulk acoustic resonator may include at least one of a dielectric constant, an elastic stiffness constant, a piezoelectric stress constant and density of a piezoelectric material of the first bulk acoustic resonator, and a density of an electrode material. Among the above-mentioned material parameters, the dielectric constant, the elastic stiffness constant, and the piezoelectric stress constant of the piezoelectric material of the first bulk acoustic resonator are material parameters that have a large influence on the performance of the first bulk acoustic resonator, and are referred to herein as "primary tuning parameters" or "primary material parameters", while the density of the piezoelectric material and the density of the electrode material are material parameters that have a small influence on the performance of the first bulk acoustic resonator, and are referred to herein as "secondary tuning parameters" or "secondary material parameters". According to an embodiment of the present disclosure, when adjusting material parameters, one, two or more of the primary material parameters are selected as primary adjustment objects, while other adjustment parameters, including non-selected primary and secondary material parameters, are selected as secondary adjustment objects. Therefore, according to the embodiment of the present disclosure, in repeatedly adjusting the material parameter of the first bulk acoustic resonator in an iterative manner such that the difference between the finite element simulation result of the physical model of the first bulk acoustic resonator and the measurement result of the first bulk acoustic resonator is within the predetermined range, at least one of the dielectric constant, the elastic stiffness constant, and the piezoelectric stress constant of the piezoelectric material of the first bulk acoustic resonator is selected as a primary material parameter to be adjusted, while the density of the piezoelectric material and the density of the electrode material are finely adjusted as secondary material parameters.

Furthermore, according to an embodiment of the present disclosure, a parameter characterizing a loss of the piezoelectric material and/or the electrode material of the first bulk acoustic resonator may also be used in a finite element simulation process of the physical model of the first bulk acoustic resonator.

Fig. 3 shows a graph comparing simulation results and measurement results of a first bulk acoustic wave resonator according to an embodiment of the present disclosure. As shown in fig. 3, the simulation result and the measurement result of the first bulk acoustic wave resonator can be made very close by repeatedly adjusting the material parameters of the first bulk acoustic wave resonator based on the comparison of the simulation result and the measurement result (frequency-impedance curve).

According to the embodiments of the present disclosure, the process of fitting the simulation result and the measurement result in an iterative manner (i.e., so that the difference therebetween is within a predetermined range) can be performed based on the taped first bulk acoustic resonator without reflowing the tape to verify the material parameters, and thus the design cycle can be shortened and the design cost can be reduced.

According to an embodiment of the present disclosure, in step S130, the adjusted material parameter may be verified using a second bulk acoustic resonator different from the first bulk acoustic resonator. According to an embodiment of the present disclosure, the second bulk acoustic wave resonator may be a bulk acoustic wave resonator having a different structure from the first bulk acoustic wave resonator. Similarly, according to the embodiment of the present disclosure, the structure of the second bulk acoustic wave resonator may also be determined according to the layout of the second bulk acoustic wave resonator.

Specifically, according to an embodiment of the present disclosure, the process of step S130 may include: establishing a physical model of the second bulk acoustic wave resonator according to the structure of the second bulk acoustic wave resonator; performing finite element simulation on the physical model of the second bulk acoustic wave resonator using the adjusted material parameters obtained in step S120, and comparing the simulation result with the measurement result of the second bulk acoustic wave resonator; and if the difference between the simulation result and the measurement result of the second bulk acoustic wave resonator is within a predetermined range, the adjusted material parameter is verified.

According to the embodiment of the present disclosure, the expression "predetermined range" used in step S130 may have the same meaning as the expression "predetermined range" used in step S120, that is, the expression "the difference between both the simulation result and the measurement result of the second bulk acoustic wave resonator is within a predetermined range" referred to in step S130 means that the percentage of the difference between both the simulation result and the measurement result of the second bulk acoustic wave resonator as compared to the measurement result is within 10%.

According to an embodiment of the present disclosure, step S130 further includes: if the adjusted material parameter is not verified, that is, the difference between the simulation result and the measurement result of the second bulk acoustic wave resonator is not within the predetermined range, the material parameter is readjusted until the differences between the simulation results and the respective measurement results of the first bulk acoustic wave resonator and the second bulk acoustic wave resonator are both within the predetermined range.

According to embodiments of the present disclosure, a method of readjusting material parameters may include selecting different primary material parameters. For example, it is assumed that in step S120, the main adjustment objects are the dielectric constant and the elastic stiffness constant of the piezoelectric material, but the material parameters adjusted in step S130 do not pass the verification performed for the second bulk acoustic wave resonator. In this case, in step S130, the main adjustment object may be replaced with the piezoelectric stress and the elastic stiffness length of the piezoelectric material (or any other main material parameter and/or combination of main material parameters different from the previous adjustment) and the material parameters may be adjusted again until the differences between the simulation results of the first bulk acoustic wave resonator and the second bulk acoustic wave resonator and their respective measurement results are within the predetermined range.

Further, according to the embodiment of the present disclosure, the multiple verification (and adjustment) of the material parameter in step S130 may be performed using two or more second bulk acoustic resonators different from each other to ensure that the differences between the simulation results and the measurement results of the first bulk acoustic resonator and the two or more second bulk acoustic resonators are within the predetermined range.

According to an embodiment of the present disclosure, in step S140, the geometry of the bulk acoustic wave resonator may be designed based on verified material parameters according to design requirements. According to embodiments of the present disclosure, the geometry of the bulk acoustic wave resonator may include the electrode shape and/or the microstructure of the bulk acoustic wave resonator. According to the embodiments of the present disclosure, the microstructure of the bulk acoustic wave resonator may be one or more of a frame structure, a protrusion structure, a depression structure, an air foil, and an air bridge inside or at the edge of the resonator.

According to the design method of the bulk acoustic wave resonator, after the finite element simulation result is fitted with the measurement result by adjusting the material parameters, the material parameters do not need to be adjusted. In other words, after the material parameters are determined, the bulk acoustic wave resonator can be designed directly based on the determined material parameters without re-measuring the performance of the designed bulk acoustic wave resonator through the flow sheet, and thus the design period can be shortened and the design cost can be reduced.

Fig. 4 shows a flow chart of a method 400 of designing a filter according to a first embodiment of the present disclosure.

As shown in fig. 4, a design method 400 of a filter according to a first embodiment of the present disclosure may include the steps of:

s410: establishing a physical model of the first bulk acoustic wave resonator according to the structure of the first bulk acoustic wave resonator;

s420: repeatedly adjusting the material parameters of the first bulk acoustic resonator in an iterative manner so that the difference between the finite element simulation result of the physical model of the first bulk acoustic resonator and the measurement result of the first bulk acoustic resonator is within a predetermined range;

s430: verifying the adjusted material parameter using a second bulk acoustic resonator different from the first bulk acoustic resonator;

s440: designing a bulk acoustic wave resonator based on the verified material parameters; and

s450: the designed bulk acoustic wave resonators are used to design the filter.

Steps S410 to S440 of the method 400 for designing a filter according to the first embodiment of the present disclosure may be identical to steps S110 to S140 of the method 100 for designing a bulk acoustic wave resonator described above, and thus, for the sake of brevity, a repetitive description of steps S410 to S440 will be omitted herein.

Furthermore, according to the first embodiment of the present disclosure, in step S450, a physical model of the filter may be built using the designed bulk acoustic wave resonators according to design requirements, and the filter may be designed and optimized using finite element analysis.

Fig. 5 shows a flow chart of a method 500 of designing a filter according to a second embodiment of the present disclosure. The design method 500 shown in fig. 5 differs from the design method 400 shown in fig. 4 in that the finite element simulation results of the filter formed by the bulk acoustic wave resonators are also taken into account during the adjustment of the material parameters of the bulk acoustic wave resonators.

Specifically, the method 500 for designing a filter according to the second embodiment of the present disclosure may include the steps of:

s510: establishing a physical model of the first bulk acoustic wave resonator and a physical model of a first filter formed by the first bulk acoustic wave resonator according to the structure of the first bulk acoustic wave resonator;

s520: repeatedly adjusting material parameters of the first bulk acoustic wave resonator in an iterative manner so that differences between finite element simulation results of physical models of the first bulk acoustic wave resonator and the first filter and measurement results of the first bulk acoustic wave resonator and the first filter are within predetermined ranges, respectively;

s530: verifying the adjusted material parameter using a second bulk acoustic resonator different from the first bulk acoustic resonator and/or a second filter different from the first filter; and

s540: designing a bulk acoustic wave resonator based on the verified material parameters; and

s550: the designed bulk acoustic wave resonators are used to design the filter.

According to the second embodiment of the present disclosure, in step S510, in addition to establishing a physical model corresponding to the manufactured first bulk acoustic wave resonator from, for example, the layout of the first bulk acoustic wave resonator similarly to step S110 in fig. 1, a physical model of the first filter constituted by the first bulk acoustic wave resonator is established. Similar to the design method 100 described above with reference to fig. 1 to 3, in step S510, the structure of the first bulk acoustic wave resonator may be determined according to the layout of the first bulk acoustic wave resonator.

Fig. 6 shows a schematic diagram of a physical model of a first filter according to an embodiment of the present disclosure, wherein each pentagonal pattern represents first bulk acoustic wave resonators that are connected by a circuit block. Further, according to the embodiment of the present disclosure, in step S510, the structure of the first filter may be determined according to the layouts of the first bulk acoustic wave resonator and the connection circuit constituting the first filter.

According to the second embodiment of the present disclosure, in step S520, in addition to the simulation of the physical model of the first bulk acoustic wave resonator by the finite element analysis to obtain the simulation result of the physical model of the first bulk acoustic wave resonator similarly to step S120 in fig. 1, the simulation of the physical model of the first filter by the finite element analysis to obtain the simulation result of the physical model of the first filter is also performed.

Accordingly, in step S520, the finite element simulation results of the physical models of the first bulk acoustic wave resonator and the first filter may be compared with the measurement results of the manufactured first bulk acoustic wave resonator and the manufactured first filter, respectively, and then the material parameters of the first bulk acoustic wave resonator may be adjusted by a method such as gradient descent according to the comparison results. Subsequently, finite element simulation of the physical models of the first bulk acoustic wave resonator and the first filter is performed again based on the adjusted material parameters, and the updated simulation result is compared with the measurement result. By adjusting the material parameters of the first bulk acoustic resonator in the above iterative manner until the difference between the finite element simulation results of the physical models of the first bulk acoustic resonator and the first filter and the measurement results of the first bulk acoustic resonator and the first filter are within the predetermined range, respectively. Here, the expression "predetermined range" may have the same meaning as that set forth above.

According to a second embodiment of the present disclosure, the adjusted material parameter of the first bulk acoustic resonator may include at least one of a dielectric constant, an elastic stiffness constant, a piezoelectric stress constant and density of the piezoelectric material of the first bulk acoustic resonator, and a density of the electrode material. Furthermore, according to the second embodiment of the present disclosure, a parameter that characterizes a loss of the piezoelectric material and/or the electrode material of the first bulk acoustic resonator may also be used in the finite element simulation process of the physical model of the first bulk acoustic resonator.

Furthermore, according to the second embodiment of the present disclosure, parameters characterizing passive elements in the filter may also be used during the finite element simulation of the physical model of the first filter. According to a second embodiment of the present disclosure, the passive elements in the first filter may comprise inductors and/or capacitors for impedance matching.

Fig. 7 shows a comparison graph of simulation results and measurement results of a filter according to an embodiment of the present disclosure. As shown in fig. 7, the simulation result and the measurement result of the first filter can be made very close by repeatedly adjusting the material parameters of the first bulk acoustic wave resonator based on the comparison of the simulation result and the measurement result (S21 parameter curve).

According to the second embodiment of the present disclosure, in step S530, the adjusted material parameter may be verified using a second bulk acoustic resonator different from the first bulk acoustic resonator and/or a second filter different from the first filter. According to an embodiment of the present disclosure, the second bulk acoustic wave resonator may be a bulk acoustic wave resonator having a different structure from the first bulk acoustic wave resonator, and the second filter may be a filter constituted by the second bulk acoustic wave resonator. Similarly, according to the second embodiment of the present disclosure, the structure of the second bulk acoustic wave resonator may also be determined from the layout of the second bulk acoustic wave resonator, and the structure of the second filter may be determined from the layout of the second bulk acoustic wave resonator and the connection circuit constituting the second filter.

Specifically, according to the second embodiment of the present disclosure, the process of step S530 may include: establishing a physical model of the second bulk acoustic wave resonator and a physical model of a second filter composed of the second bulk acoustic wave resonator according to the structure of the second bulk acoustic wave resonator; performing finite element simulation on the physical model of the second bulk acoustic wave resonator and/or the second filter using the adjusted material parameters active in step S520, and comparing the simulation result with the measurement result of the second bulk acoustic wave resonator and/or the second filter; and if the difference between the simulation result and the measurement result of the second bulk acoustic wave resonator and/or the second filter is within a predetermined range, the adjusted material parameter is verified. Here, the expression "predetermined range" may have the same meaning as that set forth above.

According to the second embodiment of the present disclosure, step S530 further includes: and if the difference between the simulation result and the measurement result of the second bulk acoustic wave resonator and/or the second filter is not in the preset range, readjusting the material parameters until the difference between the simulation result and the measurement result of the first bulk acoustic wave resonator and the second bulk acoustic wave resonator and/or the first filter and the second filter are in the preset range. Here, the process of readjusting the material parameters may be similar to the process described above with reference to step S130, and thus, for the sake of brevity, will not be described in further detail.

Further, according to the second embodiment of the present disclosure, similarly to the above-described step S130, in the verification process performed in step S530, the second bulk acoustic wave resonator and/or the second filter may include two or more second bulk acoustic wave resonators different from each other and/or two or more second filters different from each other, respectively, so as to perform verification on the adjusted material parameter a plurality of times.

According to the second embodiment of the present disclosure, in step S540, the geometry of the bulk acoustic wave resonator may be designed based on verified material parameters according to design requirements. According to embodiments of the present disclosure, the geometry of the bulk acoustic wave resonator may include the electrode shape and/or the microstructure of the bulk acoustic wave resonator. According to a second embodiment of the present disclosure, the microstructure of the bulk acoustic wave resonator may be one or more of a frame structure, a protruding structure, a recessed structure, an air foil, and an air bridge inside or at an edge of the resonator.

According to the second embodiment of the present disclosure, in step S550, a physical model of the filter may be built using the designed resonators according to design requirements, and the filter may be designed and optimized using finite element analysis.

According to the design method of the bulk acoustic wave resonator and the filter, the material parameters which are adjusted after the measurement results are fitted can be newly designed without being modified, the problem that the parameters need to be fitted by multiple flow sheets in the traditional design method is solved, the design period is shortened, and the design cost is reduced. In addition, the performance of the bulk acoustic wave resonator can be optimized and improved through finite element simulation, so that the performance of the filter is further improved. Furthermore, parameter guidance can be provided for the design and manufacture of the filter, and unnecessary slice verification is avoided.

FIG. 8 illustrates a block diagram of a general-purpose machine 800 that may be used to implement a design method according to an embodiment of the disclosure. General purpose machine 800 may be, for example, a computer system. It should be noted that the general purpose machine 800 is only one example and is not meant to imply limitations as to the scope of use or functionality of the design methods of the present disclosure. Neither should the general purpose machine 800 be interpreted as having any dependency or requirement relating to any one or combination of steps illustrated in the design methods described above.

In fig. 8, a Central Processing Unit (CPU)801 executes various processes in accordance with a program stored in a Read Only Memory (ROM)802 or a program loaded from a storage section 808 to a Random Access Memory (RAM) 803. In the RAM 803, data necessary when the CPU 801 executes various processes and the like is also stored as necessary. The CPU 801, ROM 802, and RAM 803 are connected to each other via a bus 804. An input/output interface 805 is also connected to the bus 804.

The following components are also connected to the input/output interface 805: an input section 806 (including a keyboard, a mouse, and the like), an output section 807 (including a display such as a Cathode Ray Tube (CRT), a Liquid Crystal Display (LCD), and the like, a speaker, and the like), a storage section 808 (including a hard disk, and the like), and a communication section 809 (including a network interface card such as a LAN card, a modem, and the like). The communication section 809 performs communication processing via a network such as the internet. A drive 810 may also be connected to the input/output interface 805 as desired. A removable medium 811 such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, or the like can be mounted on the drive 810 as necessary, so that a computer program read out therefrom can be mounted in the storage portion 808 as necessary.

In the case where the above-described designing method is implemented by software, a program constituting the software may be installed from a network such as the internet or from a storage medium such as the removable medium 811.

It will be understood by those skilled in the art that such a storage medium is not limited to the removable medium 811 shown in fig. 8 in which the program is stored, distributed separately from the apparatus to provide the program to the user. Examples of the removable medium 811 include a magnetic disk (including a flexible disk), an optical disk (including a compact disc read only memory (CD-ROM) and a Digital Versatile Disc (DVD)), a magneto-optical disk (including a mini-disk (MD) (registered trademark)), and a semiconductor memory. Alternatively, the storage medium may be the ROM 802, a hard disk included in the storage section 808, or the like, in which programs are stored and which are distributed to users together with the apparatus including them.

In addition, the present disclosure also provides a program product storing machine-readable instruction codes. The instruction codes are read and executed by a machine, and can execute the design method according to the disclosure. Accordingly, various storage media as listed above for carrying such program products are also included within the scope of the present disclosure.

Having described in detail in the foregoing through block diagrams, flowcharts, and/or embodiments, specific embodiments of apparatus and/or methods according to embodiments of the disclosure are illustrated. When such block diagrams, flowcharts, and/or implementations contain one or more functions and/or operations, it will be apparent to those skilled in the art that each function and/or operation in such block diagrams, flowcharts, and/or implementations can be implemented, individually and/or collectively, by a variety of hardware, software, firmware, or virtually any combination thereof. In one embodiment, several portions of the subject matter described in this specification can be implemented by Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), Digital Signal Processors (DSPs), or other integrated forms. Those skilled in the art will recognize, however, that some aspects of the embodiments described in this specification can be equivalently implemented, in whole or in part, in the form of one or more computer programs running on one or more computers (e.g., in the form of one or more computer programs running on one or more computer systems), in the form of one or more programs running on one or more processors (e.g., in the form of one or more programs running on one or more microprocessors), in the form of firmware, or in virtually any combination thereof, and, it is well within the ability of those skilled in the art to design circuits and/or write code for the present disclosure, software and/or firmware, in light of the present disclosure.

Although the present disclosure has been described with reference to exemplary embodiments thereof, those skilled in the art will appreciate that various modifications and changes may be made without departing from the spirit and scope of the present disclosure as set forth in the claims.

Claims (17)

1. A method of designing a bulk acoustic wave resonator, comprising:

establishing a physical model of a first bulk acoustic wave resonator according to the structure of the first bulk acoustic wave resonator;

iteratively adjusting material parameters of the first bulk acoustic resonator in an iterative manner such that a difference between a finite element simulation result of a physical model of the first bulk acoustic resonator and a measurement result of the first bulk acoustic resonator is within a predetermined range;

verifying the adjusted material parameter using a second bulk acoustic resonator different from the first bulk acoustic resonator; and

and designing the bulk acoustic wave resonator based on the verified material parameters.

2. The design method of claim 1, the verifying the adjusted material parameter using the second bulk acoustic wave filter comprising:

establishing a physical model of the second bulk acoustic wave resonator according to the structure of the second bulk acoustic wave resonator;

performing finite element simulation on the physical model of the second bulk acoustic resonator by using the adjusted material parameters, and comparing the simulation result with the measurement result of the second bulk acoustic resonator;

if the difference between the simulation result and the measurement result of the second bulk acoustic resonator is within the predetermined range, the adjusted material parameter is verified; and

if the difference between the simulation result and the measurement result of the second bulk acoustic resonator is not within the predetermined range, readjusting the material parameter until the difference between the simulation result and the measurement result of the first bulk acoustic resonator and the second bulk acoustic resonator are both within the predetermined range.

3. The design method according to claim 1, wherein the second bulk acoustic wave filter includes two or more second bulk acoustic wave resonators that are different from each other, and

wherein verifying the adjusted material parameter using the second bulk acoustic wave filter comprises:

respectively establishing physical models of the two or more second bulk acoustic wave resonators according to the structures of the two or more second bulk acoustic wave resonators;

performing a finite element simulation on each of the physical models of the two or more second bulk acoustic resonators using the adjusted material parameters, comparing the simulation results with the measurement results of the corresponding second bulk acoustic resonator;

if the difference between the simulation result and the measurement result of the two or more second bulk acoustic resonators is within the predetermined range, the adjusted material parameter is verified; and

if the difference between the simulation result and the measurement result of any one of the two or more second bulk acoustic wave resonators is not within the predetermined range, readjusting the material parameter until the difference between the simulation result and the measurement result of the first bulk acoustic wave resonator and the two or more second bulk acoustic wave resonators is within the predetermined range.

4. The design method of any one of claims 1 to 3, wherein the material parameter comprises at least one of a dielectric constant, an elastic stiffness constant, a piezoelectric stress constant, a piezoelectric material density, and a density of an electrode material of a piezoelectric material of the bulk acoustic wave resonator.

5. A design method according to any one of claims 1 to 3, wherein the structure of the acoustic wave resonator is determined in accordance with the layout of the bulk acoustic wave resonator.

6. A design method as claimed in claims 1 to 3, wherein parameters characterizing the loss of piezoelectric material and/or electrode material of the bulk acoustic wave resonator are also used in the finite element simulation process of the physical model of the bulk acoustic wave resonator.

7. The design method according to any one of claims 1 to 3, wherein designing the bulk acoustic wave resonator based on the verified material parameters comprises:

according to design requirements, the geometry of the bulk acoustic wave resonator is designed based on verified material parameters.

8. The design method according to claim 7, wherein the geometry of the bulk acoustic wave resonator comprises an electrode shape and/or a microstructure of the bulk acoustic wave resonator.

9. A method of designing a filter, comprising:

designing a bulk acoustic wave resonator using the design method according to any one of claims 1 to 8; and

the filter is designed using the designed bulk acoustic wave resonators.

10. A method of designing a filter, comprising:

establishing a physical model of a first bulk acoustic wave resonator and a physical model of a first filter formed by the first bulk acoustic wave resonator according to the structure of the first bulk acoustic wave resonator;

repeatedly adjusting material parameters of the first bulk acoustic wave resonator in an iterative manner so that differences between finite element simulation results of physical models of the first bulk acoustic wave resonator and the first filter and measurement results of the first bulk acoustic wave resonator and the first filter are respectively within predetermined ranges;

verifying the adjusted material parameter using a second bulk acoustic resonator different from the first bulk acoustic resonator and/or a second filter different from the first filter;

designing a bulk acoustic wave resonator based on the verified material parameters; and

the designed bulk acoustic wave resonators are used to design filters.

11. The design method of claim 10, wherein verifying the adjusted material parameter using a second bulk acoustic resonator different from the first bulk acoustic resonator and/or a second filter different from the first filter comprises:

establishing a physical model of the second bulk acoustic wave resonator and a physical model of a second filter formed by the second bulk acoustic wave resonator according to the structure of the second bulk acoustic wave resonator;

performing finite element simulation on the physical model of the second bulk acoustic wave resonator and/or the second filter using the adjusted material parameters, and comparing the simulation result with the measurement result of the second bulk acoustic wave resonator and/or the second filter;

if the difference between the simulation result and the measurement result of the second bulk acoustic resonator and/or the second filter is within the predetermined range, the adjusted material parameter passes verification; and

if the difference between the simulation result and the measurement result of the second bulk acoustic wave resonator and/or the second filter is not within the predetermined range, readjusting the material parameter until the difference between the simulation result and the measurement result of the first bulk acoustic wave resonator and the second bulk acoustic wave resonator and/or the first filter and the second filter are within the predetermined range.

12. The design method according to claim 10 or 11, wherein the structure of the bulk acoustic wave resonator is determined according to a layout of the bulk acoustic wave resonator.

13. A design method according to claim 10 or 11, wherein the material parameter comprises at least one of a dielectric constant, an elastic stiffness constant, a piezoelectric stress constant and density of a piezoelectric material of the bulk acoustic wave resonator and a density of an electrode material.

14. A design method according to claim 10 or 11, wherein the parameters characterizing the loss of piezoelectric material and/or electrode material of the bulk acoustic wave resonator are used in a finite element simulation process of a physical model of the bulk acoustic wave resonator.

15. A design method as claimed in claim 10 or 11, wherein the parameters characterizing the passive elements in the filter are used during finite element simulation of the physical model of the filter.

16. The design method of claim 15, wherein the passive elements comprise inductors and/or capacitors.

17. A computer-readable storage medium on which a computer program is stored, which computer program, when executed by a computer, implements a design method according to any one of claims 1 to 16.

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