Surface acoustic wave resonator and electronic device

Abstract

The utility model discloses a surface acoustic wave resonator and an electronic device, which are applied to the technical field of surface acoustic waves, the bottom of a first electrode finger is connected with a first bus bar through a connecting part, and the top of a second electrode finger is separated from the first bus bar; the first bus bar is provided with an extension part towards the top of the second electrode finger, and the top of the extension part is separated from the top of the corresponding second electrode finger; the top edge of the extension part is provided with a first protruding part extending in the length direction, an inner-layer edge sound velocity region is formed based on the first protruding part, an inner-layer sound velocity region is formed between the first bus bar and the inner-layer edge sound velocity region based on the extension part, and the sound velocity of the inner-layer edge sound velocity region is smaller than that of the inner-layer sound velocity region. The first protruding parts are arranged at the top of the extending part, the inner layer edge sound velocity area is formed based on the first protruding parts, the sawtooth structure formed by the multiple first protruding parts can enable sound waves to generate diffuse reflection in transverse propagation, and generation of a transverse mode is effectively restrained.

Description

Technical Field

[0001] This utility model relates to the field of surface acoustic wave technology, and in particular to a surface acoustic wave resonator and an electronic device. Background Technology

[0002] Surface acoustic wave (SAW) devices are solid-state devices that utilize surface acoustic waves propagating on the surface of piezoelectric materials. Due to their excellent performance, low cost, and simple manufacturing process, they have been widely used in wireless communication. Traditional SAW filters generate transverse modes during sound wave propagation, which reduce the Q value of the SAW device. Therefore, effectively suppressing the transverse modes generated by SAW devices during sound wave propagation is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0003] The purpose of this invention is to provide a surface acoustic wave resonator that can effectively suppress the generation of transverse modes; another purpose of this invention is to provide an electronic device that can effectively suppress the generation of transverse modes.

[0004] To solve the above-mentioned technical problems, this utility model provides a surface acoustic wave resonator, comprising:

[0005] Piezoelectric substrate;

[0006] Interdigital transducers disposed on the surface of the piezoelectric substrate;

[0007] The interdigital transducer includes a first busbar and a second busbar arranged opposite to each other, both of which are parallel to the length direction; a first electrode finger and a second electrode finger are arranged between the first busbar and the second busbar, the bottom of the first electrode finger is connected to the first busbar through a connecting part, and the top of the second electrode finger is separated from the first busbar;

[0008] The first busbar has an extension portion facing the top of the second electrode finger, and the top of the extension portion is separated from the top of the corresponding second electrode finger; the top edge of the extension portion has a first protrusion extending along the length direction, and an inner edge sound velocity region is formed based on the first protrusion portion. An inner sound velocity region is formed between the first busbar and the inner edge sound velocity region based on the extension portion, and the sound velocity of the inner edge sound velocity region is less than the sound velocity of the inner layer sound velocity region.

[0009] Optionally, the top edge of the extension is provided with the first protrusion on both sides along the length direction.

[0010] Optionally, the connecting portion has a first protrusion at the edge corresponding to the top of the extension portion.

[0011] Optionally, the connecting portion has the first protrusion on both sides of the position corresponding to the top of the extension portion.

[0012] Optionally, in the length direction, the width of the extension, the width of the connecting portion, the width of the first electrode finger, and the width of the second electrode finger are all the same;

[0013] And / or, the extension, the connection, the first electrode finger, and the second electrode finger are all parallel to each other.

[0014] Optionally, there is a gap between the top of the extension and the top of the corresponding second electrode finger, and a transition sound velocity region is formed based on the gap, wherein the sound velocity of the inner sound velocity region is less than that of the transition sound velocity region.

[0015] Optionally, an outer sound velocity region is formed based on the first busbar, wherein the sound velocity in the outer sound velocity region is greater than the sound velocity in the inner sound velocity region.

[0016] Optionally, the top edge of the second electrode finger is provided with a second protrusion extending along the length direction, and a central edge sound velocity region is formed based on the second protrusion; a central sound velocity region is formed based on the first electrode finger and the second electrode finger, and the sound velocity of the central edge sound velocity region is less than the sound velocity of the central sound velocity region.

[0017] Optionally, the bottom edge of the first electrode finger is provided with a second protrusion.

[0018] This invention also provides an electronic device, including a surface acoustic wave resonator as described in any of the preceding claims.

[0019] The present invention provides a surface acoustic wave resonator, comprising: a piezoelectric substrate; an interdigital transducer disposed on the surface of the piezoelectric substrate; the interdigital transducer includes a first busbar and a second busbar disposed opposite to each other, both of which are parallel to the length direction; a first electrode finger and a second electrode finger are disposed between the first busbar and the second busbar, the bottom of the first electrode finger being connected to the first busbar through a connecting portion, and the top of the second electrode finger being separated from the first busbar; an extension portion is disposed on the first busbar facing the top of the second electrode finger, the top of the extension portion being separated from the top of the corresponding second electrode finger; a first protrusion extending along the length direction is disposed on the top edge of the extension portion, forming an inner edge sound velocity region based on the first protrusion portion, and an inner layer sound velocity region is formed between the first busbar and the inner edge sound velocity region based on the extension portion, wherein the sound velocity of the inner edge sound velocity region is less than the sound velocity of the inner layer sound velocity region.

[0020] By setting an extension in the interdigital transducer and a first protrusion on the top of the extension, and forming an inner edge sound velocity region based on the first protrusion, the sawtooth structure formed by multiple first protrusions can cause diffuse reflection of sound waves during transverse propagation due to the difference between the sound velocity of the inner edge sound velocity region and the sound velocity of the inner layer sound velocity region formed by the extension. This reduces the Q value of the transverse clutter mode and effectively suppresses the generation of transverse modes.

[0021] This utility model also provides an electronic device that has the same beneficial effects as described above, which will not be described in detail here. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of a surface acoustic wave resonator provided in an embodiment of the present invention;

[0024] Figure 2 A partial structural schematic diagram of the first surface acoustic wave resonator provided in an embodiment of this utility model;

[0025] Figure 3 This is a schematic diagram of half of the surface acoustic wave resonator in the control group;

[0026] Figure 4 A comparison chart of frequency impedance characteristic curves;

[0027] Figure 5 This is a comparison chart of Q-value curves.

[0028] In the figure: 1. Piezoelectric substrate, 2. First busbar, 31. First electrode finger, 32. Second electrode finger, 4. Connecting part, 5. Extension part, 6. First protrusion, 7. Second protrusion;

[0029] 10. Inner edge sound velocity region, 20. Inner layer sound velocity region, 30. Center sound velocity region, 40. Transitional sound velocity region, 50. Outer layer sound velocity region, 60. Center edge sound velocity region. Detailed Implementation

[0030] The core of this invention is to provide a surface acoustic wave (SAW) resonator. In the prior art, SAW filters generate transverse modes during sound wave propagation, which reduces the Q value of the SAW device.

[0031] The surface acoustic wave resonator provided by this utility model includes: a piezoelectric substrate; an interdigital transducer disposed on the surface of the piezoelectric substrate; the interdigital transducer includes a first busbar and a second busbar disposed opposite to each other, both of which are parallel to the length direction; a first electrode finger and a second electrode finger are disposed between the first busbar and the second busbar, the bottom of the first electrode finger is connected to the first busbar through a connecting portion, and the top of the second electrode finger is separated from the first busbar; an extension portion is disposed on the first busbar facing the top of the second electrode finger, and the top of the extension portion is separated from the top of the corresponding second electrode finger; a first protrusion extending along the length direction is disposed on the top edge of the extension portion, and an inner edge sound velocity region is formed based on the first protrusion portion, and an inner layer sound velocity region is formed between the first busbar and the inner edge sound velocity region based on the extension portion, wherein the sound velocity of the inner edge sound velocity region is less than the sound velocity of the inner layer sound velocity region.

[0032] By setting an extension in the interdigital transducer and a first protrusion on the top of the extension, and forming an inner edge sound velocity region based on the first protrusion, the sawtooth structure formed by multiple first protrusions can cause diffuse reflection of sound waves during transverse propagation due to the difference between the sound velocity of the inner edge sound velocity region and the sound velocity of the inner layer sound velocity region formed by the extension. This reduces the Q value of the transverse clutter mode and effectively suppresses the generation of transverse modes.

[0033] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Example 1

[0035] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a surface acoustic wave resonator provided in an embodiment of the present invention.

[0036] See Figure 1In this embodiment of the invention, the surface acoustic wave resonator includes: a piezoelectric substrate 1; an interdigital transducer disposed on the surface of the piezoelectric substrate 1; the interdigital transducer includes a first busbar 2 and a second busbar disposed opposite to each other, both the first busbar 2 and the second busbar being parallel to the length direction; a first electrode finger 31 and a second electrode finger 32 are disposed between the first busbar 2 and the second busbar, the bottom of the first electrode finger 31 being connected to the first busbar 2 through a connecting portion 4, and the top of the second electrode finger 32 being connected to the first busbar 2. The first busbar 2 is provided with an extension 5 facing the top of the second electrode finger 32, and the top of the extension 5 is separated from the top of the corresponding second electrode finger 32; the top edge of the extension 5 is provided with a first protrusion 6 extending along the length direction, and an inner edge sound velocity region 10 is formed based on the first protrusion 6. An inner sound velocity region 20 is formed between the first busbar 2 and the inner edge sound velocity region 10 based on the extension 5, and the sound velocity of the inner edge sound velocity region 10 is less than the sound velocity of the inner edge sound velocity region 20.

[0037] The piezoelectric substrate 1 mentioned above is typically a substrate made of piezoelectric ceramic. The piezoelectric substrate 1 is a key component in surface acoustic wave resonators, utilizing the propagation characteristics of surface acoustic waves on the material surface to achieve functions such as signal filtering and frequency control. The piezoelectric substrate 1 has sensitive characteristics, capable of converting extremely weak mechanical vibrations into electrical signals. The specific material of the piezoelectric substrate 1 is not specifically limited in this embodiment; its details can be found in existing technologies and will not be elaborated further here.

[0038] An interdigital transducer is disposed on the surface of the piezoelectric substrate 1, its main function being to achieve the interconversion between electrical signals and surface acoustic waves (SAWs). Specifically, the interdigital transducer accomplishes this conversion process primarily through the piezoelectric effect and the inverse piezoelectric effect. When an alternating electrical signal is applied to the input terminal of the interdigital transducer, a periodically distributed electric field is generated on the surface of the piezoelectric substrate 1 due to the inverse piezoelectric effect. This electric field induces elastic deformation near the surface of the piezoelectric medium, thereby forming a SAW, which propagates along the surface of the piezoelectric substrate 1.

[0039] For interdigital transducers, they have a length direction and a width direction. The length direction is the direction in which multiple interdigital transducers are arranged, which is also the direction in which surface acoustic waves are transmitted; while the width direction is the direction perpendicular to the length direction.

[0040] In this embodiment, the interdigital transducer has a first busbar 2 and a second busbar arranged opposite to each other. The first busbar 2 and the second busbar are typically provided with input terminals that are electrically connected to external devices. Electrode fingers are provided between the first busbar 2 and the second busbar. The first busbar 2 and the second busbar are both parallel to the length direction, that is, parallel to the extension direction of the interdigital transducer, and the first busbar 2 and the second busbar are parallel to each other.

[0041] The interdigital transducer also includes parallel electrode fingers, all parallel to the width direction, positioned between the first busbar 2 and the second busbar. Specifically, each electrode finger includes a first electrode finger 31 and a second electrode finger 32. The first electrode finger 31 is electrically connected to the first busbar 2, and the second electrode finger 32 is electrically connected to the second busbar. The first electrode finger 31 and the second electrode finger 32 are typically arranged alternately along the length direction, allowing them to connect alternately to the busbars on both sides. It should be noted that in this embodiment, either of the two busbars can be the first busbar 2, and the other is the second busbar. The electrode finger connected to the first busbar 2 is the first electrode finger 31, and the electrode finger not connected to the first busbar 2 is the second electrode finger 32. In this embodiment, the interdigital transducer has a symmetrical structure along the width direction; either side of the busbar can be the first busbar 2, and the structure of the other side can refer to the structure of the opposite side, which will not be elaborated further here.

[0042] In this embodiment, the bottom of the first electrode finger 31 is connected to the first busbar 2 via the connecting part 4, and the top of the second electrode finger 32 is separated from the first busbar 2. Each of the electrode fingers has two opposing ends, specifically a top and a bottom. In the width direction, the bottom of the first electrode finger 31 and the top of the second electrode finger 32 are approximately at the same position and are arranged opposite each other; similarly, the bottom of the second electrode finger 32 is also approximately at the same position as the top of the first electrode finger 31 and is arranged opposite each other. For the half-interdigital transducer, the busbar of this half-interdigital transducer is the first busbar 2, which is connected to the bottom of the first electrode finger 31 via the connecting part 4, and is separated from the top of the second electrode finger 32. For the other half-interdigital transducer, the busbar of this other half-interdigital transducer can also be determined as the first busbar 2, and its structure is similar to that of the opposite half-interdigital transducer, and will not be described further here. Obviously, the connecting part 4 will connect the first electrode finger 31 to the first bus bar 2 on the side facing the electrode finger, and the electrode finger will alternately connect to the bus bars on both sides.

[0043] In this embodiment, the first busbar 2 facing the electrode finger side is further provided with an extension 5. Specifically, the extension 5 extends from the edge of the first busbar 2 facing the second electrode finger 32 towards the top of the second electrode finger 32, but the top of the extension 5 must remain separate from the top of the second electrode finger 32. Furthermore, a first protrusion 6 extending along the length direction is provided at the top edge of the extension 5, and multiple first protrusions 6 are arranged along the length direction. The first protrusion 6 is specifically a structure on the same layer as the extension 5; generally, the various structures of the interdigital transducer described above in this application are all on the same layer. The first protrusion 6 is specifically provided at the top edge of the extension 5, and it protrudes beyond the outline of the top of the extension 5 along the length direction. That is, a single first protrusion 6 extends along the length direction, while multiple first protrusions 6 are arranged along the length direction. In this embodiment, an inner edge sound velocity region 10 is formed based on the first protrusion 6. The inner edge sound velocity region 10 extends along the length direction. The inner edge sound velocity region 10 includes not only the first protrusion 6, but also the top of the extension 5 and the structure of the connecting part 4 corresponding to the top of the extension 5, which are all located within the range of the inner edge sound velocity region 10.

[0044] In this embodiment, an inner sound velocity region 20 is formed between the first busbar 2 and the inner edge sound velocity region 10 based on the extension portion 5. That is, the inner sound velocity region 20 is formed based on the remaining structure after removing the top of the extension portion 5. Specifically, the inner sound velocity region 20 is located between the first busbar 2 and the inner edge sound velocity region 10. The inner sound velocity region 20 includes not only a portion of the extension portion 5 (i.e., the remaining structure after removing the top of the extension portion 5) but also a portion of the connecting portion 4. That is, the structure in the connecting portion 4 corresponding to the remaining structure of the extension portion 5 is located within the range of the inner sound velocity region 20. The inner sound velocity region 20 also extends along the length direction. The inner edge sound velocity region 10 and the inner sound velocity region 20 are arranged adjacent to each other along the width direction. In this embodiment, the sound velocity of the inner edge sound velocity region 10 is less than the sound velocity of the inner sound velocity region 20, thereby creating a sound velocity gradient in the width direction. Furthermore, the aforementioned multiple first protrusions 6 form a sawtooth structure, causing diffuse reflection of sound waves during transverse propagation, thereby reducing the Q value of transverse clutter modes and effectively suppressing the generation of transverse modes.

[0045] In this embodiment, the first protrusion 6 may be an integral structure with the extension 5, that is, the extension 5 and the first protrusion 6 may be in the same layer to facilitate the setting of the structure.

[0046] In one example, the top edge of the extension 5 has the first protrusion 6 on both sides along the length direction. That is, the first protrusion 6 is provided above and below the top of the extension 5 along the length direction. In another example, the connecting part 4 has the first protrusion 6 at the edge corresponding to the top of the extension 5. That is, in the inner edge sound velocity region 10, the first protrusion 6 is not only provided at the top of the extension 5, but can also be provided at the position of the connecting part 4 corresponding to the top of the extension 5. In this case, the first protrusion 6 is located within the inner edge sound velocity region 10. This structure can increase the density of the first protrusion 6 and increase the scattering performance of the tooth-like structure formed by the first protrusion 6.

[0047] In another example, the connecting portion 4 has first protrusions 6 on both sides of its edge corresponding to the top of the extension portion 5. That is, along the length direction, first protrusions 6 can also be provided on both sides of the connecting portion 4 simultaneously. In this case, two opposing but not connected first protrusions 6 will be formed in the region between adjacent connecting portions 4 and extension portions 5. This structure can further increase the density of the first protrusions 6 and further increase the scattering performance of the tooth-like structure formed by the first protrusions 6.

[0048] Normally, the dimensions of the first protrusions 6 at the above-mentioned locations can be the same, which facilitates the fabrication of the interdigital transducer. Of course, in this embodiment, the specific dimensions of the first protrusions 6 are not specifically limited, but depend on the specific circumstances.

[0049] The surface acoustic wave resonator provided in this embodiment provides an extension 5 in the interdigital transducer and a first protrusion 6 on the top of the extension 5. An inner edge sound velocity region 10 is formed based on the first protrusion 6. Due to the difference in sound velocity between the inner edge sound velocity region 10 and the inner sound velocity region 20 formed by the extension 5, the sawtooth structure formed by multiple first protrusions 6 can cause diffuse reflection of sound waves during transverse propagation, thereby reducing the Q value of transverse clutter modes and effectively suppressing the generation of transverse modes.

[0050] The specific details of the surface acoustic wave resonator provided in this application will be described in detail in the following utility model embodiments.

[0051] Example 2

[0052] Please refer to Figure 2 , Figure 2 This is a partial structural schematic diagram of the first surface acoustic wave resonator provided in the embodiment of this utility model.

[0053] Unlike the embodiments described above, this embodiment further defines the structure of the interdigital transducer based on the above embodiments. The remaining details have been described in detail in the above embodiments and will not be repeated here.

[0054] See Figure 2 In this embodiment, in the length direction, the width of the extension 5, the width of the connecting part 4, the width of the first electrode finger 31, and the width of the second electrode finger 32 are all the same; and / or, the extension 5, the connecting part 4, the first electrode finger 31, and the second electrode finger 32 are all parallel to each other.

[0055] That is, along the length direction, the dimensions of the extension 5, the connecting part 4, the first electrode finger 31, and the second electrode finger 32 are all the same. Furthermore, structurally, the extension 5, the connecting part 4, the first electrode finger 31, and the second electrode finger 32 are all parallel to each other. At this time, a central sound velocity region 30 is formed based on the first electrode finger 31 and the second electrode finger 32. The structure of this central sound velocity region 30 is the same as the structure of the inner sound velocity region 20 formed based on the extension 5 and the connecting part 4, and correspondingly, the sound velocity of the central sound velocity region 30 is the same as the sound velocity of the inner sound velocity region 20.

[0056] In this embodiment, there is a gap between the top of the extension 5 and the top of the corresponding second electrode finger 32, and a transition sound velocity region 40 is formed based on the gap, wherein the sound velocity of the inner layer sound velocity region 20 is less than the sound velocity of the transition sound velocity region 40.

[0057] The aforementioned transitional sound velocity region 40 extends along the length direction and is located on the side of the inner edge sound velocity region 10 away from the inner layer sound velocity region 20, adjacent to it. Since there is no material of the same layer as the electrode fingers in the location of the gap, the transitional sound velocity region 40 formed along the length direction based on the gap only has the structure of the connecting portion 4 and no structure of the extension portion 5. Therefore, the density of the structure in the transitional sound velocity region 40 is lower than the sound velocity of the inner layer sound velocity region 20, and correspondingly, the sound velocity of the transitional sound velocity region 40 is greater than the sound velocity of the inner layer sound velocity region 20, and it is also necessarily greater than the sound velocity of the inner edge sound velocity region 10.

[0058] In this embodiment, an outer sound velocity region 50 is formed based on the first busbar 2, and the sound velocity in the outer sound velocity region 50 is greater than the sound velocity in the inner sound velocity region 20. The outer sound velocity region 50, extending along its length, is formed at the location of the first busbar 2. This outer sound velocity region 50 typically contains only the first busbar 2, and its sound velocity is usually greater than that of the inner sound velocity region 20, thus creating a sound velocity gradient at the edge of the differential transducer. In a feasible example, the sound velocity in the transition sound velocity region 40 is greater than that in the outer sound velocity region 50.

[0059] In this embodiment, the top edge of the second electrode finger 32 is provided with a second protrusion 7 extending along the length direction, and a central edge sound velocity region 60 is formed based on the second protrusion 7; a central sound velocity region 30 is formed based on the first electrode finger 31 and the second electrode finger 32, and the sound velocity of the central edge sound velocity region 60 is less than the sound velocity of the central sound velocity region 30.

[0060] The aforementioned second protrusion 7 is at least disposed at the top edge of the second electrode finger 32, and protrudes beyond the outline of the top edge of the second electrode finger 32 along its length. Multiple second protrusions 7 are arranged along the length direction. Specifically, the second protrusion 7 can be a structure located on the same layer as the second electrode finger 32. In this embodiment, a central edge sound velocity region 60 is formed based on the second protrusions 7. The central edge sound velocity region 60 extends along the length direction and includes not only the second protrusions 7, but also the top of the second electrode finger 32 and the bottom of the first electrode finger 31, all located within the range of the central edge sound velocity region 60. The central edge sound velocity region 60 and the central sound velocity region 30 are arranged adjacent to each other along the width direction. In this embodiment, the sound velocity of the central edge sound velocity region 60 is less than that of the central sound velocity region 30, thus creating a sound velocity gradient in the width direction. Furthermore, the multiple second protrusions 7 form a sawtooth structure, causing diffuse reflection of sound waves during transverse propagation, thereby reducing the Q value of transverse clutter modes and effectively suppressing the generation of transverse modes.

[0061] In one example, the second electrode finger 32 has second protrusions 7 on both sides of its top edge along the length direction. That is, second protrusions 7 are provided above and below the top of the second electrode finger 32 along the length direction. In another example, the second protrusions 7 are provided on the bottom edge of the first electrode finger 31. That is, in the central edge sound velocity region 60, the second protrusions 7 are not only provided on the top of the second electrode finger 32, but also on the bottom of the first electrode finger 31. In this case, the bottom of the first electrode finger 31 and the top of the second electrode finger 32 correspond to each other along the length direction and are located in the same column. In this case, the second protrusions 7 are all located within the inner edge sound velocity region 10. This structure can increase the density of the second protrusions 7 and increase the scattering performance of the tooth-like structure formed by the second protrusions 7.

[0062] In another example, the second protrusions 7 are provided on both sides of the bottom edge of the first electrode finger 31. That is, along the length direction, the second protrusions 7 can also be provided on both sides of the bottom of the first electrode finger 31 simultaneously. In this case, two opposing but not connected second protrusions 7 will be formed in the region between adjacent first electrode fingers 31 and second electrode fingers 32. This structure can further increase the density of the second protrusions 7 and further increase the scattering performance of the tooth-like structure formed by the first protrusions 6.

[0063] Normally, the dimensions of the second protrusions 7 at the above-mentioned positions can be the same, which facilitates the fabrication of the interdigital transducer. Of course, in this embodiment, the specific dimensions of the second protrusions 7 are not specifically limited, but depend on the specific circumstances.

[0064] In this embodiment, the interdigital transducer points from its center along the width direction towards one side edge, and its sound velocity is typically in the order of medium → low → high → low → medium → high. The "low" sound velocity corresponds to the center edge sound velocity region 60 and the inner edge sound velocity region 10; the "medium" sound velocity corresponds to the center sound velocity region 30 and the inner sound velocity region 2020; and the "high" sound velocity corresponds to the transition sound velocity region 40 and the outer sound velocity region 50. This structure has multiple sound velocity gradients along the width direction, which minimizes the Q value of clutter modes during lateral propagation of the sound wave, effectively suppressing the generation of lateral modes. Furthermore, the multiple different sound velocity regions effectively suppress different lateral modes during sound wave propagation.

[0065] In this embodiment, the structure of the first protrusion 6 and the structure of the second protrusion 7 are not specifically limited. They can be rectangular, triangular, trapezoidal, etc., and are not specifically limited here.

[0066] The surface acoustic wave resonator provided in this embodiment, by setting an inner edge sound velocity region 10 based on a first protrusion 6 and a central edge sound velocity region 60 based on a second protrusion 7, the sawtooth structure formed by multiple first protrusions 6 and multiple second protrusions 7 can cause diffuse reflection of sound waves during transverse propagation, thereby reducing the Q value of transverse clutter modes and effectively suppressing the generation of transverse modes.

[0067] Example 3

[0068] Please refer to Figures 3 to 5 , Figure 3 This is a schematic diagram of half of the surface acoustic wave resonator in the control group; Figure 4 A comparison graph of frequency impedance characteristic curves; Figure 5 This is a comparison chart of Q-value curves.

[0069] See Figure 3 as well as Figure 2 In this embodiment, specifically, will be Figure 3 The surface acoustic wave resonator in the middle is used as a control group. Figure 2 The surface acoustic wave (SAW) resonator in the control group was used as the experimental group to compare the performance of the two SAW resonators. Compared to the experimental group structure described in the above embodiments, the control group structure essentially removed the first protrusion 6. The data comparison between the two groups demonstrates the role of the first protrusion 6 in the SAW resonator. The comparison results are as follows: Figure 4 as well as Figure 5 As shown in the figure, the dashed line represents the data results of the control group, and the solid line represents the data results of the experimental group.

[0070] See Figure 4 as well as Figure 5 Compared to the control group without the first protrusion 6, the interdigital transducers with the first protrusion 6 in the experimental group can have higher maximum Q value and maximum impedance. A high Q value is beneficial for designing filters with lower insertion loss and steeper roll-off.

[0071] Example 4

[0072] The following describes an electronic device provided by an embodiment of the present invention. The electronic device described below can be referred to in correspondence with the surface acoustic wave resonator described above.

[0073] In this embodiment, the electronic device includes a surface acoustic wave resonator provided in any of the above-described utility model embodiments. The specific structure of the surface acoustic wave resonator has been described in detail in the above-described utility model embodiments and will not be repeated here. Other structures of the electronic device, such as antennas and housings, can be referenced from the prior art and will not be described further here.

[0074] Since the electronic device provided in this embodiment specifically uses the surface acoustic wave resonator provided in the above embodiment, the electronic device can effectively suppress the generation of transverse modes, thereby having a higher Q value.

[0075] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0076] The surface acoustic wave resonator and electronic device provided by this utility model have been described in detail above. Specific examples have been used to illustrate the principle and implementation of this utility model. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core idea of ​​this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. A surface acoustic wave resonator, characterized in that, include: Piezoelectric substrate; Interdigital transducers disposed on the surface of the piezoelectric substrate; The interdigital transducer includes a first busbar and a second busbar arranged opposite to each other, both of which are parallel to the length direction; a first electrode finger and a second electrode finger are arranged between the first busbar and the second busbar, the bottom of the first electrode finger is connected to the first busbar through a connecting part, and the top of the second electrode finger is separated from the first busbar; The first busbar has an extension portion facing the top of the second electrode finger, and the top of the extension portion is separated from the top of the corresponding second electrode finger; the top edge of the extension portion has a first protrusion extending along the length direction, and an inner edge sound velocity region is formed based on the first protrusion portion. An inner sound velocity region is formed between the first busbar and the inner edge sound velocity region based on the extension portion, and the sound velocity of the inner edge sound velocity region is less than the sound velocity of the inner layer sound velocity region.

2. The surface acoustic wave resonator according to claim 1, characterized in that, The top edge of the extension has the first protrusion on both sides along the length direction.

3. The surface acoustic wave resonator according to claim 1, characterized in that, The connecting portion has a first protrusion at the edge corresponding to the top of the extension portion.

4. The surface acoustic wave resonator according to claim 3, characterized in that, The connecting portion has the first protrusion on both sides of the top of the extension portion.

5. The surface acoustic wave resonator according to claim 1, characterized in that, In the length direction, the width of the extension, the width of the connecting portion, the width of the first electrode finger, and the width of the second electrode finger are all the same; And / or, the extension, the connection, the first electrode finger, and the second electrode finger are all parallel to each other.

6. The surface acoustic wave resonator according to claim 1, characterized in that, There is a gap between the top of the extension and the top of the corresponding second electrode finger, and a transition sound velocity region is formed based on the gap, wherein the sound velocity of the inner sound velocity region is less than the sound velocity of the transition sound velocity region.

7. The surface acoustic wave resonator according to claim 1, characterized in that, An outer sound velocity region is formed based on the first busbar, and the sound velocity in the outer sound velocity region is greater than that in the inner sound velocity region.

8. The surface acoustic wave resonator according to claim 1, characterized in that, The top edge of the second electrode finger is provided with a second protrusion extending along the length direction, and a central edge sound velocity region is formed based on the second protrusion; a central sound velocity region is formed based on the first electrode finger and the second electrode finger, and the sound velocity of the central edge sound velocity region is less than the sound velocity of the central sound velocity region.

9. The surface acoustic wave resonator according to claim 8, characterized in that, The bottom edge of the first electrode finger is provided with the second protrusion.

10. An electronic device, characterized in that, Includes the surface acoustic wave resonator as described in any one of claims 1 to 9.

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