CN114124021A - Elastic wave resonator and multi-passband filter - Google Patents
Elastic wave resonator and multi-passband filter Download PDFInfo
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/02—Details
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/46—Filters
- H03H9/54—Filters comprising resonators of piezoelectric or electrostrictive material
- H03H9/56—Monolithic crystal filters
- H03H9/564—Monolithic crystal filters implemented with thin-film techniques
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/46—Filters
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- Physics & Mathematics (AREA)
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Abstract
The elastic wave resonator and the multi-passband filter disclosed in the embodiment of the application comprise a substrate, a first electrode layer, a piezoelectric film and a second electrode layer. The piezoelectric film comprises a plurality of etching areas and a plurality of non-etching areas, the ratio of the depth of each etching area to the thickness of the piezoelectric film is in an interval [0.4,1 ], the ratio of the center distance between every two adjacent etching areas to the thickness of the piezoelectric film is in an interval [0.4,1.25], a first electrode layer is arranged on a substrate, the piezoelectric film is arranged on the first electrode layer, a second electrode layer is arranged on the piezoelectric film, and the piezoelectric film is partially etched by taking the second electrode layer as a mask. The resonator can obtain a plurality of resonance without spurious modes and with large electromechanical coupling coefficient in a larger frequency interval. Based on this application embodiment through the sculpture size and the sculpture degree of depth of adjusting piezoelectric film, can change resonant frequency and electromechanical coupling coefficient, can build many passband filters.
Description
Technical Field
The invention relates to the field of microelectronic devices, in particular to an elastic wave resonator and a multi-passband filter.
Background
With the continuous development of mobile communication technology, the electromagnetic wave frequency band used in the 5G era will continue to develop towards high frequency and large bandwidth. The radio frequency acoustic filter has the advantages of high out-of-band rejection, low insertion loss, small device size, low manufacturing cost and the like, is considered to be the best device of the current Sub-6GHz mobile radio frequency front end, and mainly comprises a surface acoustic wave filter SAW and a bulk wave filter BAW. The filter is constructed by cascading, bridging or coupling a plurality of resonators based on a topology, wherein cascading is the most common way, for example, a ladder filter.
Mature 5G technology will increase more than 50 communication frequency bands, and at the moment, 2G/3G/4G/5G in the world can support 91 frequency bands in total. In the general case, each filter has a particular passband frequency response characteristic. To support more frequency bands, a plurality of filters can be connected in parallel to obtain the multi-channel comprehensive characteristic of adding the characteristics of a single filter, however, the number of the filters is increased by connecting a plurality of filters in parallel, which is not beneficial to the miniaturization and integration of the radio frequency front end. The other better method is to use the multi-mode resonators to obtain the multi-passband filter in a cascading, bridging and other modes, and compared with the former method, the number of the filters is greatly reduced, and the size of the filters is reduced.
The electromechanical coupling coefficient of the acoustic resonator is positively correlated with the absolute value of the piezoelectric coefficient of the piezoelectric material, and the electromechanical coupling coefficient of the SAW resonator is mainly related to the piezoelectric coefficient | e1iAnd | i ═ 1,5, 6). Due to the anisotropy of the piezoelectric material, the absolute value of each piezoelectric coefficient in a fixed propagation direction is a large value, so that it is difficult to obtain a large electromechanical coupling coefficient in each acoustic wave mode. Bulk wave filter BAW usually uses aluminum nitride AlN as piezoelectric material due to its piezoelectricityThe coefficient is small, the electromechanical coupling coefficient exceeding 10% is difficult to realize, and the requirement of large bandwidth in the 5G era cannot be met.
Disclosure of Invention
The embodiment of the application provides an elastic wave resonator and a multi-passband filter, and the elastic wave resonator can obtain resonance of a plurality of spurious-free modes and a large electromechanical coupling coefficient in a larger frequency interval. The resonance frequency and the electromechanical coupling coefficient of the elastic wave resonator can be changed by the photoetching size and the etching depth, and a multi-passband filter can be formed.
An embodiment of the present application provides an elastic wave resonator, which includes: the piezoelectric element comprises a substrate, a first electrode layer, a piezoelectric film and a second electrode layer;
the piezoelectric film comprises a plurality of etching areas and a plurality of non-etching areas, the ratio of the depth of the etching areas to the depth of the non-etching areas is in an interval [0.4,1 ], and the ratio of the center distance between two adjacent etching areas to the depth of the non-etching areas is in an interval [0.4,1.25 ];
a first electrode layer disposed on the substrate;
the piezoelectric film is arranged on the first electrode layer;
the second electrode layer is disposed on the non-etched region of the piezoelectric film.
Further, the material of the first electrode layer is at least one of aluminum, tungsten, chromium, titanium, copper, silver, molybdenum and gold.
Further, the material of the second electrode layer is at least one of nickel, tungsten, chromium, titanium and aluminum.
Further, the material of the piezoelectric film is lithium niobate or lithium tantalate.
Further, the cut type of the piezoelectric film is an X-cut type.
Further, the material of the substrate includes, but is not limited to, any one of diamond and silicon carbide.
Further, the elastic wave resonator is in a two-dimensional vibration mode;
the characteristic dimension of the elastic wave resonator in the X direction is in a sub-wavelength state, and the characteristic dimension of the elastic wave resonator in the Z direction is in a sub-wavelength state.
Correspondingly, the embodiment of the application also provides a multi-passband filter, which comprises a plurality of elastic wave resonators, wherein the elastic wave resonators are the elastic wave resonators, and the plurality of elastic wave resonators are cascaded, bridged or coupled based on a preset topological structure.
The embodiment of the application has the following beneficial effects:
the elastic wave resonator and the multi-passband filter disclosed in the embodiment of the application comprise a substrate, a first electrode layer, a piezoelectric film and a second electrode layer. The piezoelectric film comprises a plurality of etching areas and a plurality of non-etching areas, the ratio of the depth of the etching areas to the depth of the non-etching areas is in an interval [0.4,1 ], the ratio of the center distance between two adjacent etching areas to the depth of the non-etching areas is in an interval [0.4,1.25], the first electrode layer is arranged on the substrate, and the piezoelectric film is arranged on the first electrode layer. The second electrode layer is disposed on the non-etched region of the piezoelectric film. The coupled resonance of SAW and BAW can be realized based on the elastic wave resonator in the embodiment of the application. And the resonator can obtain a plurality of resonance without stray modes and large electromechanical coupling coefficient in a larger frequency interval, and the resonance frequency and the electromechanical coupling coefficient of the resonator can be changed by adjusting the etching size and the etching depth of the piezoelectric film, so that a multi-passband and large-bandwidth filter can be built. In addition, the first electrode layer, the piezoelectric film and the second electrode layer are bonded with the high-sound-velocity supporting substrate, so that the mechanical stability of the device is good. The bottom electrode of the floating potential can reduce mutual electromagnetic interference between resonators in the filter.
Drawings
In order to more clearly illustrate the technical solutions and advantages of the embodiments of the present application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative efforts.
Fig. 1 is a schematic structural diagram of an elastic wave resonator provided in an embodiment of the present application;
fig. 2 is a resonance mode diagram of a two-dimensional vibration elastic wave resonator according to an embodiment of the present application;
FIG. 3 is a schematic diagram of admittance simulation curves of elastic wave resonators with different lithographic dimensions according to an embodiment of the present application
FIG. 4 is a schematic diagram of an admittance simulation curve of an elastic wave resonator with different etching depths according to an embodiment of the present application;
FIG. 5 is a graph illustrating admittance simulation curves of example 1 and comparative example 1 provided in the examples of the present application;
fig. 6 is a schematic diagram of admittance simulation curves of example 1 and comparative example 2 provided in the examples of the present application.
Fig. 7 is a schematic diagram of a topology of a multiple passband filter according to an embodiment of the present disclosure;
fig. 8 is a simulation graph of S-parameters of a multi-passband filter according to an embodiment of the present disclosure.
Reference numerals:
100-substrate, 200-first electrode layer, 300-piezoelectric film, 400-second electrode layer.
Detailed Description
To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings. It should be apparent that the described embodiment is only one embodiment of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
An "embodiment" as referred to herein relates to a particular feature, structure, or characteristic that may be included in at least one implementation of the present application. In the description of the embodiments of the present application, it should be understood that the terms "upper", "lower", "left", "right", "top", "bottom", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only used for convenience in describing the present application and simplifying the description, and do not indicate or imply that the devices/systems or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be taken as limiting the present application. The terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," and the like are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in other sequences than described or illustrated herein. Furthermore, the terms "comprises" and "comprising," as well as any variations thereof, are intended to cover non-exclusive inclusions.
A specific embodiment of an elastic wave resonator according to the present application will be described below, and fig. 1 is a schematic structural view of an elastic wave resonator according to an embodiment of the present application, and the present specification provides constituent structures as shown in the embodiments or schematic views, but may include more or less constituent structures based on conventional or non-inventive labor. The constituent structure recited in the embodiment is only one of a plurality of constituent structures, and does not represent a unique constituent structure, and in actual execution, the constituent structure can be executed according to the constituent structure shown in the embodiment or the schematic diagram.
Specifically, as shown in fig. 1, the elastic wave resonator may include a substrate 100, a first electrode layer 200, a piezoelectric thin film 300, and a second electrode layer 400. The piezoelectric film 300 may include a plurality of etched regions and a plurality of non-etched regions, a ratio of a depth of an etched region to a depth of a non-etched region may be in a range [0.4,1 ], and a ratio of a center distance between two adjacent etched regions to a depth of a non-etched region may be in a range [0.4,1.25 ]. The first electrode layer 200 may be disposed on the substrate 100, the piezoelectric thin film 300 may be disposed on the first electrode layer 200, and the second electrode layer 400 may be disposed on the non-etched region of the piezoelectric thin film 300. By adjusting the photoetching size and the etching depth of the piezoelectric film, the resonance frequency and the electromechanical coupling coefficient of the elastic wave resonator can be changed, and the multi-passband filter can be conveniently built subsequently.
In an alternative implementation, the elastic wave resonator may be a two-dimensional vibration elastic wave resonator, and fig. 2 is a resonance diagram of a two-dimensional vibration elastic wave resonator provided in an embodiment of the present application, and feature sizes of the two-dimensional vibration elastic wave resonator in both the X direction and the Z direction may be in a sub-wavelength state. The two-dimensional vibration mode of the two-dimensional vibration elastic wave resonator can change the resonance frequency and the electromechanical coupling coefficient thereof by changing the sizes of the X direction and the Z direction, namely by adjusting the photoetching size and the etching depth.
In an alternative embodiment, the substrate 100 may be a high acoustic velocity support substrate 100, and the material of the substrate 100 may be diamond, silicon carbide, or other materials, and the embodiments of the present invention are not limited in particular. By bonding the first electrode layer 200, the piezoelectric thin film 300, and the second electrode layer 400 to the high acoustic velocity support substrate 100, the mechanical stability of the device is good. The first electrode layer 200 may be a bottom electrode, which may be disposed on the substrate 100. The piezoelectric film 300 may be disposed on the bottom electrode, and the material thereof may be lithium niobate or lithium tantalate. The second electrode layer 400 may be an interdigital electrode, which may be disposed on the piezoelectric film 300, and the interdigital electrode may serve as a mask for the piezoelectric film 300 to implement partial etching of the piezoelectric film 300, so as to obtain an etched region and a non-etched region.
In an alternative embodiment, the depth of the etched region may be denoted by letter d, the depth of the non-etched region may be denoted by letter h, and the center-to-center distance between two adjacent etched regions may be denoted by letter p. FIG. 3 is a schematic diagram of admittance simulation curves of elastic wave resonators with different lithographic dimensions, according to an embodiment of the present application, where a distance p between two adjacent etched regions should satisfy 0.8 < p < 2.5 h. As is clear from fig. 3, when p is too large, the number of acoustic wave modes decreases between larger frequency regions, and when p is too small, the electromechanical coupling coefficient of the acoustic wave mode is small. Fig. 4 is a schematic diagram of admittance simulation curves of resonators with different etching depths provided by the embodiment of the present application, where the etching depth of the piezoelectric film 300 should satisfy 0.4h < d < 1 h. As can be clearly seen from fig. 4, when the etching depth is small, the stray mode cannot be suppressed well, and when the etching is completed, the bottom electrode will be damaged.
In the embodiment of the present application, the material of the first electrode layer 200, i.e., the bottom electrode, may be at least one of nickel, tungsten, chromium, titanium, and aluminum, and the bottom electrode may be in a floating potential state. The bottom electrode of the floating potential can reduce mutual electromagnetic interference between resonators in the filter.
In this embodiment, the material of the second electrode layer 400 may be at least one of aluminum, tungsten, chromium, titanium, copper, silver, molybdenum, and gold, or may be another metal material used as a mask material for lithium niobate etching or lithium tantalate etching. That is, the interdigital electrode may be formed of one of the above-described plurality of metal materials, or may be formed of two of the above-described plurality of metal materials.
In the embodiment of the present application, the cut of the piezoelectric film 300 may be an X-cut, and optionally, the piezoelectric film 300 may be an X-cut lithium niobate, or an X-cut lithium tantalate. However, the lithium niobate in which the piezoelectric thin film is X-cut is only one embodiment described in the examples of the present application, and the piezoelectric thin film may be other types of cut lithium niobate or lithium tantalate, and the examples of the present application are not particularly limited.
Next, taking the structure of a two-dimensional vibrating elastic wave resonator having a two-dimensional vibration mode shown in fig. 2 as an example, 2 comparative examples were provided to explain the performance and superiority of the two-dimensional vibrating elastic wave resonator.
Example 1: diamond is used as a supporting substrate 100, aluminum Al is used as a material of a bottom electrode, X-cut lithium niobate is used as a piezoelectric film material, and Al is used as a material of an interdigital electrode. The thickness of the bottom layer electrode can be 50nm, the thickness of the piezoelectric film can be 600nm, namely the depth of a non-etching area can be 600nm, the etching depth of the piezoelectric film can be 300nm, the depth of an immediate etching area can be 300nm, and the included angle between the in-plane transmission direction of the piezoelectric film and a-Y axis can be 56 degrees, namely the Euler angle can be [56,90,90 ]. The thickness of the interdigital electrodes can be 50nm, and the center distance between two adjacent interdigital electrodes can be 1 μm.
Comparative example 1: with aluminum nitride AlN as a material of the piezoelectric film, the rest of the arrangement may be the same as example 1.
Comparative example 2: the conventional SAW resonator, which has no bottom electrode, does not partially etch the piezoelectric film, which is Z-cut lithium niobate, and the rest of the setup may be the same as in example 1.
Fig. 5 is a schematic diagram of admittance simulation curves of example 1 and comparative example 1 provided in the examples of the present application. Since AlN has a much smaller piezoelectric coefficient than lithium niobate, the electromechanical coupling coefficient of a resonator using AlN as the material of the piezoelectric thin film 300 is much smaller than that of a resonator using lithium niobate as the material of the piezoelectric thin film 300, and thus cannot satisfy the requirement of a large bandwidth in the age of 5G. In addition, AlN excites fewer acoustic wave modes than lithium niobate in a certain frequency range because AlN has stronger crystal symmetry, i.e., weaker anisotropy, and a smaller number of independent and non-zero piezoelectric coefficients.
Fig. 6 is a schematic diagram of admittance simulation curves of example 1 and comparative example 2 provided in the examples of the present application. It can be seen that it is difficult to obtain a large electromechanical coupling coefficient in each acoustic wave mode due to the anisotropy of the lithium niobate material in comparative example 2, and the structure shown in example 1 can excite both BAW and SAW acoustic wave modes simultaneously and convert BAW into SAW on the substrate surface, so that the electromechanical coupling coefficient of each excited acoustic wave mode is larger than that of comparative example 2.
The two-dimensional vibration elastic wave resonator provided by the embodiment of the application can realize the coupling resonance of SAW and BAW. In addition, the resonator can obtain a plurality of resonance without stray modes and large electromechanical coupling coefficient in a larger frequency interval, and the resonance frequency and the electromechanical coupling coefficient of the resonator can be changed by adjusting the etching size and the etching depth of the piezoelectric film. In addition, by bonding the first electrode layer, the piezoelectric thin film, and the second electrode layer to the high acoustic velocity support substrate, mechanical stability of the device can be improved. The bottom electrode of the floating potential can reduce mutual electromagnetic interference between resonators in the filter.
The embodiment of the application provides a multi-passband filter, which can comprise a plurality of elastic wave resonators, and the plurality of elastic wave resonators can be cascaded, bridged or coupled based on a preset topological structure.
Fig. 7 is a schematic view of a topology structure of a multiple passband filter according to an embodiment of the present application, and the performance of the constructed multiple passband filter will be described below by taking the topology structure shown in fig. 7 as an example 2.
Example 2: diamond is used as a supporting substrate, aluminum Al is used as a material of a bottom electrode, X-cut lithium niobate is used as a piezoelectric film, and Al is used as a material of an interdigital electrode. The thickness of the bottom layer electrode can be 50nm, the thickness of the piezoelectric film can be 600nm, namely the depth of a non-etching area can be 600nm, the etching depth of the piezoelectric film can be 300nm, the depth of an immediate etching area can be 300nm, and the included angle between the in-plane transmission direction of the piezoelectric film and a-Y axis can be 56 degrees, namely the Euler angle can be [56,90,90 ]. The interdigital electrode may have a thickness of 50 nm. The center distance between two adjacent interdigital electrodes of the series resonator may be 0.85 μm. The center distance between two adjacent interdigital electrodes of the parallel resonator is 0.94 um.
Fig. 8 is a simulation graph of S-parameters of a multi-passband filter provided in an embodiment of the present application, and it can be seen from the graph that the filter has small in-band ripples and large bandwidth. Simulation results prove that the elastic wave resonator provided by the embodiment of the application can be used for forming a multi-passband large-bandwidth filter.
In an alternative embodiment, each resonator may include a substrate, a first electrode layer, a piezoelectric film, and a second electrode layer. The piezoelectric film can comprise a plurality of etching areas and a plurality of non-etching areas, the ratio of the depth of the etching areas to the depth of the non-etching areas can be in an interval [0.4,1 ], and the ratio of the center distance between two adjacent etching areas to the depth of the non-etching areas can be in an interval [0.4,1.25 ]. The first electrode layer may be disposed on the substrate, the piezoelectric film may be disposed on the first electrode layer, and the second electrode layer may be disposed on the non-etched region of the piezoelectric film. The distance p between two adjacent etching areas should satisfy 0.8 < p < 2.5h, and the etching depth of the piezoelectric film should satisfy 0.4 < d < 1 h. Wherein, the letter d may indicate the depth of the etching region, the letter h may indicate the depth of the non-etching region, and the letter p may indicate the center-to-center distance between two adjacent etching regions.
By adopting the multi-passband filter provided by the embodiment of the application, the requirement of large bandwidth in the 5G era can be met.
As can be seen from the above-described embodiments of the elastic wave resonator or the multiple band pass filter provided in the present application, the elastic wave resonator in the present application includes a substrate, a first electrode layer, a piezoelectric film, and a second electrode layer. The piezoelectric film comprises a plurality of etching areas and a plurality of non-etching areas, the ratio of the depth of the etching areas to the depth of the non-etching areas is in an interval [0.4,1 ], the ratio of the center distance between two adjacent etching areas to the depth of the non-etching areas is in an interval [0.4,1.25], the first electrode layer is arranged on the substrate, and the piezoelectric film is arranged on the first electrode layer. The second electrode layer is disposed on the non-etched region of the piezoelectric film. SAW and BAW coupling resonance can be realized based on the two-dimensional vibration elastic wave resonator in the embodiment of the application. Moreover, the elastic wave resonator can obtain a plurality of resonances without stray modes and with large electromechanical coupling coefficients in a larger frequency interval, and the resonance frequency and the electromechanical coupling coefficients can be changed by adjusting the etching size and the etching depth of the piezoelectric film, so that the multi-passband and large-bandwidth filter can be built. In addition, by combining the first electrode layer, the piezoelectric film, and the second electrode layer with the high acoustic velocity support substrate, the mechanical stability of the device can be improved. The bottom electrode of the floating potential can reduce mutual electromagnetic interference between resonators in the filter.
In the present invention, unless otherwise expressly stated or limited, the terms "connected" and "connected" are to be construed broadly, e.g., as meaning either a fixed connection or a removable connection, or an integral part; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
It should be noted that: the foregoing sequence of the embodiments of the present application is for description only and does not represent the superiority and inferiority of the embodiments, and the specific embodiments are described in the specification, and other embodiments are also within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in the order of execution in different embodiments and achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown or connected to enable the desired results to be achieved, and in some embodiments, multitasking and parallel processing may also be possible or may be advantageous.
All the embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments may be referred to each other, and each embodiment is described with emphasis on differences from other embodiments. Especially, for the embodiment of the filter, since it is based on the similar method embodiment, the description is simple, and the relevant points can be referred to the partial description of the method embodiment.
While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.
Claims (8)
1. An elastic wave resonator, comprising: the piezoelectric element comprises a substrate, a first electrode layer, a piezoelectric film and a second electrode layer;
the piezoelectric film comprises a plurality of etching areas and a plurality of non-etching areas, the ratio of the depth of each etching area to the thickness of the piezoelectric film is in an interval [0.4,1 ], and the ratio of the center distance between every two adjacent etching areas to the piezoelectric film is in an interval [0.4,1.25 ];
the first electrode layer is arranged on the substrate;
the piezoelectric film is arranged on the first electrode layer;
the second electrode layer is disposed on the non-etched region of the piezoelectric film.
2. The elastic wave resonator according to claim 1, wherein a material of the first electrode layer is at least one of aluminum, tungsten, chromium, titanium, copper, silver, molybdenum, and gold.
3. The elastic wave resonator according to claim 1, wherein a material of the second electrode layer is at least one of nickel, tungsten, chromium, titanium, and aluminum.
4. The elastic wave resonator according to claim 1, wherein a material of the piezoelectric thin film is lithium niobate or lithium tantalate.
5. The elastic wave resonator according to claim 4, wherein the piezoelectric thin film is X-cut lithium niobate or X-cut lithium tantalate.
6. The elastic wave resonator according to claim 1, wherein the support substrate includes, but is not limited to, any one of diamond and silicon carbide.
7. The elastic wave resonator according to claim 1, wherein the elastic wave resonator is a two-dimensional vibration mode;
the characteristic dimension of the elastic wave resonator in the X direction is in a sub-wavelength state, and the characteristic dimension of the elastic wave resonator in the Z direction is in a sub-wavelength state.
8. A multiple band pass filter comprising a plurality of elastic wave resonators according to any one of claims 1 to 7, wherein the plurality of elastic wave resonators are cascaded, bridged or coupled based on a predetermined topology.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115276593A (en) * | 2022-06-27 | 2022-11-01 | 上海馨欧集成微电有限公司 | Acoustic wave resonator and filter |
| CN115296636A (en) * | 2022-03-22 | 2022-11-04 | 中国科学院上海微系统与信息技术研究所 | Preparation method of acoustic wave resonator, structure of acoustic wave resonator and filter |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20180323769A1 (en) * | 2015-10-30 | 2018-11-08 | Kyocera Corporation | Acoustic wave resonator, acoustic wave filter, multiplexer, communication apparatus, and method designing acoustic wave resonator |
| CN113098419A (en) * | 2021-04-07 | 2021-07-09 | 清华大学 | High electromechanical coupling coefficient surface acoustic wave device based on etched piezoelectric film |
| CN113300683A (en) * | 2021-05-25 | 2021-08-24 | 中国科学院上海微系统与信息技术研究所 | Surface acoustic wave resonator and preparation method thereof |
-
2021
- 2021-11-29 CN CN202111437446.7A patent/CN114124021A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20180323769A1 (en) * | 2015-10-30 | 2018-11-08 | Kyocera Corporation | Acoustic wave resonator, acoustic wave filter, multiplexer, communication apparatus, and method designing acoustic wave resonator |
| CN113098419A (en) * | 2021-04-07 | 2021-07-09 | 清华大学 | High electromechanical coupling coefficient surface acoustic wave device based on etched piezoelectric film |
| CN113300683A (en) * | 2021-05-25 | 2021-08-24 | 中国科学院上海微系统与信息技术研究所 | Surface acoustic wave resonator and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 袁巨龙: "《功能陶瓷的超精密加工技术》", 哈尔滨工业大学出版社, pages: 9 - 11 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115296636A (en) * | 2022-03-22 | 2022-11-04 | 中国科学院上海微系统与信息技术研究所 | Preparation method of acoustic wave resonator, structure of acoustic wave resonator and filter |
| CN115276593A (en) * | 2022-06-27 | 2022-11-01 | 上海馨欧集成微电有限公司 | Acoustic wave resonator and filter |
| CN115276593B (en) * | 2022-06-27 | 2023-03-28 | 上海馨欧集成微电有限公司 | Acoustic wave resonator and filter |
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