Surface acoustic wave device, filter and radio frequency front-end module

Abstract

The invention provides a surface acoustic wave device, a filter and a radio frequency front end module, the surface acoustic wave device comprises a piezoelectric substrate and an interdigital transducer, and the interdigital transducer is arranged on the piezoelectric substrate; the interdigital transducer comprises two bus bars and an electrode unit, and the two bus bars are oppositely arranged in a spaced mode in the first direction; the two electrode structures of the electrode unit are arranged between the two bus bars; the two electrode structures are respectively connected with one bus bar; the electrode structure comprises a connecting part, a conductive part and at least two finger strip parts, the connecting part comprises a connecting strip, the bus bar is connected with the conductive part through the connecting strip, and the finger strip parts of the electrode structure are connected with the conductive part; the finger strip parts are arranged at intervals in the second direction perpendicular to the first direction. In the first direction, an intersection area and a non-intersection area are arranged between the two bus bars, and the connecting part and the conductive part are arranged in the non-intersection area; in the same electrode structure, the number of the connecting strips is smaller than that of the finger strip parts so as to reduce or avoid the influence of a miscellaneous mode on the performance of the surface acoustic wave device.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a surface acoustic wave device, a filter and a radio frequency front-end module. Background Art

[0002] Surface acoustic wave devices utilize the characteristics of acoustic-electric transducers to process acoustic signals propagating on the surface of materials with piezoelectric properties. Surface acoustic wave devices have the advantages of low cost, small size and multiple functions, so they have been widely used in radar, communication, navigation, identification and other fields. Surface acoustic wave devices include interdigital transducers (IDTs), which can convert electrical signals into acoustic signals or convert acoustic signals into electrical signals. When the surface acoustic wave device is working, in addition to the lateral stray generated by the acoustic wave in the aperture direction, there are also stray modes in the gap area formed between the bus bar and the multiple electrode fingers, referred to as stray modes. The existence of stray modes will have a significant impact on the performance of the surface acoustic wave device. Summary of the invention

[0003] The present application provides a surface acoustic wave device, a filter and a radio frequency front-end module, aiming to reduce or avoid the influence of stray modes on the performance of the surface acoustic wave device.

[0004] The present application provides a surface acoustic wave device, the surface acoustic wave device comprising a piezoelectric substrate and an interdigital transducer, the interdigital transducer being arranged on the piezoelectric substrate; the interdigital transducer comprising:

[0005] Two bus bars, the two bus bars are arranged opposite to each other at an interval along a first direction;

[0006] An electrode unit, comprising two electrode structures, wherein the two electrode structures are arranged between the two bus bars; the two electrode structures are each connected to one bus bar; the electrode structure comprises a connecting portion, a conductive portion and at least two finger portions, the connecting portion comprises a connecting bar, the bus bar is connected to the conductive portion via the connecting bar, and the finger portion of the electrode structure is connected to the conductive portion; the finger portions are arranged at intervals along a second direction perpendicular to the first direction; in the first direction, there are a crossing area and a non-crossing area between the two bus bars, the connecting portion and the conductive portion are arranged in the non-crossing area; in the second direction, the crossing area is an area where the finger portions overlap each other;

[0007] Among them, in the same electrode structure, the number of the connecting strips is less than the number of the finger strip portions; the non-intersection area includes a first gap area, the first gap area is the area between the bus bar and the conductive part, and the area where the finger tip of at least one finger strip portion of the electrode structure extends along the first direction toward the bus bar connected to another electrode structure is defined as the first area, the area in the non-intersection area other than the first gap area is the second area, and the area where the first area and the second area overlap with each other is the preset area; no conductive structure is provided in the preset area.

[0008] The embodiment of the present application further provides a surface acoustic wave device, the surface acoustic wave device comprising a piezoelectric substrate and an interdigital transducer, the interdigital transducer being arranged on the piezoelectric substrate; the interdigital transducer comprising:

[0009] Two bus bars, the two bus bars are arranged opposite to each other at an interval along a first direction;

[0010] An electrode unit, comprising two electrode structures, wherein the two electrode structures are arranged between the two bus bars; the two electrode structures are each connected to one bus bar; the electrode structure comprises a connecting portion, a conductive portion and at least two finger portions, the connecting portion comprises a connecting bar, the bus bar is connected to the conductive portion via the connecting bar, and the finger portion of the electrode structure is connected to the conductive portion; the finger portions are arranged at intervals along a second direction perpendicular to the first direction; in the first direction, there are a crossing area and a non-crossing area between the two bus bars, the connecting portion and the conductive portion are arranged in the non-crossing area; in the second direction, the crossing area is an area where the finger portions overlap each other;

[0011] Among them, in the same electrode structure, the number of the connecting strips is less than the number of the finger strip portions, and the finger end of at least one finger strip portion of the electrode structure in the first direction is not provided with a conductive structure within a preset distance from the finger end, and the preset distance is less than or equal to 0.8λ, where λ is the wavelength of the surface acoustic wave device.

[0012] The embodiment of the present application further provides a surface acoustic wave device, the surface acoustic wave device comprising a piezoelectric substrate and an interdigital transducer, the interdigital transducer being arranged on the piezoelectric substrate; the interdigital transducer comprising:

[0013] Two bus bars, the two bus bars are arranged opposite to each other at an interval along a first direction;

[0014] An electrode unit, comprising two electrode structures, wherein the two electrode structures are arranged between the two bus bars; the two electrode structures are each connected to one bus bar; the electrode structure comprises a connecting portion, a conductive portion and at least two finger portions, the connecting portion comprises a connecting bar, the bus bar is connected to the conductive portion via the connecting bar, and the finger portion of the electrode structure is connected to the conductive portion; the finger portions are arranged at intervals along a second direction perpendicular to the first direction; in the first direction, there are a crossing area and a non-crossing area between the two bus bars, the connecting portion and the conductive portion are arranged in the non-crossing area; in the second direction, the crossing area is an area where the finger portions overlap each other;

[0015] Among them, in the same electrode structure, the number of the connecting strips is less than the number of the finger strip portions; the finger strip portions of the two electrode structures are respectively a first finger strip portion and a second finger strip portion, one of the electrode structures includes a first sub-unit, and the other electrode structure includes a second sub-unit, and the first sub-unit and the second sub-unit are alternately arranged along the second direction; the first sub-unit includes at least two adjacent first finger strip portions, and the second sub-unit includes at least two adjacent second finger strip portions.

[0016] The embodiment of the present application further provides a surface acoustic wave device, the surface acoustic wave device comprising a piezoelectric substrate and an interdigital transducer, the interdigital transducer being arranged on the piezoelectric substrate; the interdigital transducer comprising:

[0017] Two bus bars, the two bus bars are arranged opposite to each other at an interval along a first direction;

[0018] An electrode unit, comprising two electrode structures, wherein the two electrode structures are arranged between the two bus bars; the two electrode structures are each connected to one bus bar; the electrode structure comprises a connecting portion, a conductive portion and at least two finger portions, the connecting portion comprises a connecting bar, the bus bar is connected to the conductive portion via the connecting bar, and the finger portion of the electrode structure is connected to the conductive portion; the finger portions are arranged at intervals along a second direction perpendicular to the first direction; in the first direction, there are a crossing area and a non-crossing area between the two bus bars, the connecting portion and the conductive portion are arranged in the non-crossing area; in the second direction, the crossing area is an area where the finger portions overlap each other;

[0019] Among them, in the same electrode structure, the number of the connecting bars is less than the number of the finger portions, and the ratio of the number of the finger portions to the number of the connecting bars is A, and A is greater than 1 and less than or equal to 8.

[0020] An embodiment of the present application also provides a filter, comprising any of the surface acoustic wave devices described above.

[0021] An embodiment of the present application also provides a radio frequency front-end module, comprising a surface acoustic wave device as described in any one of the above items.

[0022] The surface acoustic wave device, filter and RF front-end module provided by the present application connect at least two finger-strip parts through a conductive part, which can change the original periodicity of the finger-strip parts, thereby weakening the stray mode; and by making the number of connecting strips in the same electrode structure smaller than the number of finger-strip parts, that is, at least two finger-strip parts connected together are connected to the bus bar through connecting strips less than this number, the possibility of generating an equivalent resonant cavity in the non-intersection area can be reduced, thereby reducing the possibility of oscillation of the stray mode, and minimizing or avoiding the probability of exciting the sound wave energy leaking from the intersection area to the non-intersection area, thereby achieving the suppression of the stray mode, thereby reducing or avoiding the stray mode affecting the performance of the surface acoustic wave device.

[0023] It should be understood that the above general description and the following detailed description are merely exemplary and explanatory and cannot limit the disclosure of the embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 It is a schematic diagram of the structure of a surface acoustic wave device in the related art;

[0026] Figure 2 is a schematic structural diagram of a surface acoustic wave device provided in one embodiment of the present application;

[0027] Figure 3 is a schematic structural diagram of a surface acoustic wave device provided in one embodiment of the present application;

[0028] Figure 4 is a schematic structural diagram of a surface acoustic wave device provided in one embodiment of the present application;

[0029] Figure 5 is a schematic structural diagram of a surface acoustic wave device provided in one embodiment of the present application;

[0030] Figure 6 is a schematic structural diagram of a surface acoustic wave device provided in one embodiment of the present application;

[0031] Figure 7 is a schematic structural diagram of a surface acoustic wave device provided in one embodiment of the present application;

[0032] Figure 8 is a comparison diagram of the admittance curves of the surface acoustic wave device of the related art and the present embodiment;

[0033] Fig. 9 is a comparison diagram of the admittance curves of the surface acoustic wave device of the related art and the present embodiment;

[0034] Fig.10 is a comparison diagram of the admittance curves of the surface acoustic wave device of the related art and the present embodiment;

[0035] Fig.11 4 is a comparison diagram of Q values ​​of the surface acoustic wave devices of the related art and this embodiment.

[0036] Description of reference numerals:

[0037] 1000. Surface acoustic wave devices;

[0038] 100, piezoelectric substrate; 101, substrate; 102, piezoelectric film;

[0039] 200, interdigital transducer;

[0040] 10. bus bar; 11. first bus bar; 12. second bus bar;

[0041] 20. Electrode unit; 21. Electrode structure; 21a. First electrode structure; 21b. Second electrode structure; 21c. First subunit; 21d. Second subunit; 211. Connecting part; 2111. Connecting bar; 2111a. First connecting bar; 2111b. Second connecting bar; 212. Conductive part; 2121. First conductive part; 2122. Second conductive part; 213. Finger bar; 2131. First finger bar; 2132. Second finger bar; 214. Fake finger; 2141. First fake finger; 2142. Second fake finger;

[0042] 30, dielectric layer; 40, low sound velocity part;

[0043] 300, reflective structure;

[0044] A1, intersection area; A11, middle area; A12, edge area; B1, non-intersection area; B11, first gap area; B12, second gap area; C1, first area; C2, second area; C3, preset area. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0046] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0047] It should also be understood that the terms used in this application specification are only for the purpose of describing specific embodiments and are not intended to limit the application. As used in this application specification and the appended claims, the singular forms "a", "an" and "the" are intended to include plural forms unless the context clearly indicates otherwise.

[0048] It should be further understood that the term “and / or” used in the specification and appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0049] See also Figure 1 , the surface acoustic wave device 1000 in the related art generally includes a piezoelectric substrate 100 and an interdigital transducer 200, and the interdigital transducer 200 is disposed on the piezoelectric substrate 100. The interdigital transducer 200 cooperates with the piezoelectric substrate 100 to convert an electrical signal into an acoustic wave or convert an acoustic wave into an electrical signal. Exemplarily, the surface acoustic wave device 1000 may also include a reflection structure 300, and the reflection structure 300 may be disposed on two opposite sides of the interdigital transducer 200. Specifically, in the direction of acoustic wave propagation, the reflection structure 300 is disposed on two opposite sides of the interdigital transducer 200; the reflection structure 300 is used to reflect the acoustic wave and confine the acoustic wave to the area where the interdigital transducer 200 is located.

[0050] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0051] In some embodiments of the present application, the surface acoustic wave device 1000 may include a surface acoustic wave resonator. The surface acoustic wave resonator may be a normal surface acoustic wave resonator (Normal-SAW), a temperature compensated surface acoustic wave resonator (TC-SAW), a surface acoustic wave resonator with a multi-layer substrate structure, or a transversely excited thin film bulk acoustic wave resonator, etc.

[0052] In some embodiments, the material of the piezoelectric substrate 100 may specifically include at least one of quartz, aluminum nitride, sapphire, LN (lithium niobate, Li NbO 3 ), LT (lithium tantalate, Li TaO 3 ), etc., which is not specifically limited in this embodiment.

[0053] See also Figure 2 In some embodiments, the piezoelectric substrate 100 includes a stacked piezoelectric film 102 and a substrate 101, and the interdigital transducer 200 is disposed on the surface of the piezoelectric film 102 away from the substrate 101. In this way, the Q value of the surface acoustic wave device 1000 can be improved and can be applied to higher frequency bands of 5G and above. Exemplarily, the material of the substrate 101 can be silicon.

[0054] In some embodiments, the material of the IDT 200 may be a single metal material or a composite or alloy material of different metals. Optionally, the material of the IDT 200 may be aluminum, molybdenum, copper, gold, platinum, silver, nickel, chromium, tungsten, or a composite of the above metals or one of their alloys.

[0055] See also Figure 3In some embodiments, the interdigital transducer 200 includes a bus bar 10 and an electrode unit 20, the number of the bus bars 10 includes two, and the two bus bars 10 are arranged opposite to each other along a first direction; the electrode unit 20 includes two electrode structures 21, and the two electrode structures 21 are arranged between the two bus bars 10; the two electrode structures 21 are each connected to one bus bar 10; the electrode structure 21 includes a connecting portion 211, a conductive portion 212 and at least two finger portions 213, the connecting portion 211 includes a connecting bar 2111, the bus bar 10 is connected to the conductive portion 212 through the connecting bar 2111, and the finger portion 213 of the electrode structure 21 is connected to the conductive portion 212; each finger portion 213 is arranged at intervals along a second direction perpendicular to the first direction; in the first direction, there is an intersection area A1 and a non-intersection area B1 between the two bus bars 10, and the connecting portion 211 and the conductive portion 212 are arranged in the non-intersection area B1; in the second direction, the intersection area A1 is an area where each finger portion 213 overlaps with each other. Among them, in the same electrode structure 21, the number of connecting bars 2111 is less than the number of finger portions 213; the non-intersection area B1 includes a first gap area B11, the first gap area B11 is the area between the bus bar 10 and the conductive portion 212, and the area where the finger tip of at least one finger portion 213 of the electrode structure 21 extends along the first direction toward the bus bar 10 connected to another electrode structure 21 is defined as the first area C1, the area in the non-intersection area B1 except the first gap area B11 is the second area C2, and the area where the first area C1 and the second area C2 overlap with each other is the preset area C3; no conductive structure is provided in the preset area C3.

[0056] The surface acoustic wave device 1000 of the above-mentioned embodiment connects at least two finger portions 213 through the conductive portion 212, which can change the original periodicity of the finger portion 213, thereby weakening the stray mode; and because the number of connecting bars 2111 in the same electrode structure 21 is less than the number of finger portions 213, that is, at least two finger portions 213 connected together are connected to the bus bar 10 through connecting bars 2111 less than the number, it can reduce the possibility of generating an equivalent resonant cavity in the non-intersection area B1, thereby reducing the possibility of oscillation of the stray mode, and reducing or avoiding the probability of exciting the acoustic wave energy leaked from the intersection area A1 to the non-intersection area B1, thereby achieving the suppression of the stray mode, thereby reducing or avoiding the stray mode affecting the performance of the surface acoustic wave device 1000. In addition, since there is no conductive structure in the preset area C3 where the first area C1 and the second area C2 overlap with each other, compared with a case where a conductive structure is provided in the preset area C3, the embodiment of the present application can effectively suppress the stray modes on the high-frequency side of the anti-resonance point and improve the stray mode suppression effect; the processing is simple; it is conducive to saving the use of conductive materials, thereby facilitating the lightweighting of the product and reducing costs.

[0057] Exemplarily, a conductive structure, i.e., a structure having conductive properties, refers to a structure made of a conductive material, such as metal. A conductive structure is not provided, which at least includes a structure not provided with at least one of the following materials: a material used to prepare the interdigital transducer 200, a material used to prepare the conductive portion 212, a material used to prepare the finger portion 213, a material used to prepare the bus bar 10, and any other suitable conductive material.

[0058] See also Figure 3 , exemplarily, the non-intersection area B1 includes a first gap area B11 and a second gap area B12, the first gap area B11 is the area between the bus bar 10 and the conductive portion 212, and the second gap area B12 is the area between the intersection area A1 and the conductive portion 212. In the first direction, there is an intersection area A1 between the two bus bars 10, and the intersection area A1 includes a middle area A11 and edge areas A12 located on both sides of the middle area A11.

[0059] See also Figure 4 Exemplarily, the two bus bars 10 are respectively the first bus bar 11 and the second bus bar 12, and the first bus bar 11 and the second bus bar 12 are arranged on the piezoelectric substrate 100 at intervals along the first direction. The two electrode structures 21 are respectively the first electrode structure 21a and the second electrode structure 21b, the finger portion 213 of the first electrode structure 21a is the first finger portion 2131, the conductive portion 212 of the first electrode structure 21a is the first conductive portion 2121, and the connecting portion 211 of the first electrode structure 21a includes a first connecting bar 2111a; the finger portion 213 of the second electrode structure 21b is the second finger portion 2132, the conductive portion 212 of the second electrode structure 21b is the second conductive portion 2122, and the connecting portion 211 of the second electrode structure 21b includes a second connecting bar 2111b. The first bus bar 11 is connected to the first conductive part 2121 through the first connecting bar 2111a, and the first conductive part 2121 is connected to at least two first finger parts 2131; in the first electrode structure 21a, the number of the first connecting bars 2111a is less than the number of the first finger parts 2131. The second bus bar 12 is connected to the second conductive part 2122 through the second connecting bar 2111b, and the second conductive part 2122 is connected to at least two second finger parts 2132. In the second electrode structure 21b, the number of the second connecting bars 2111b is less than the number of the second finger parts 2132. The first finger parts 2131 and the second finger parts 2132 are arranged at intervals along a second direction perpendicular to the first direction. Exemplarily, the first direction is perpendicular to the second direction means that the first direction is perpendicular to the second direction on the plane where the piezoelectric substrate 100 is located. For example, the first direction is the arrangement direction of the two bus bars 10 or the length extension direction of the finger bar portion 213, and the second direction is the sound wave propagation direction or the arrangement direction of each finger bar portion 213. Figure 3 The X direction is shown in the second direction. Figure 3 As shown in the Y direction.

[0060] See also Figure 4 , exemplarily, the two electrode structures 21 are both arranged between the first bus bar 11 and the second bus bar 12; in the first direction, one end of the first connecting bar 2111a is connected to the first bus bar 11, the other end of the first connecting bar 2111a is connected to the first conductive portion 2121, one end of the first finger portion 2131 is connected to the first conductive portion 2121, the other end of the first finger portion 2131 is spaced apart from the second conductive portion 2122, and the other end of the first finger portion 2131 is spaced apart from the second bus bar 12; in the first direction, one end of the second connecting bar 2111b is connected to the second bus bar 12, the other end of the second connecting bar 2111b is connected to the second conductive portion 2122, one end of the second finger portion 2132 is connected to the second conductive portion 2122, the other end of the second finger portion 2132 is spaced apart from the first conductive portion 2121, and the other end of the second finger portion 2132 is spaced apart from the first bus bar 11. It is understandable that the ends of the first finger portions 2131 close to the second bus bar 12 may be flush or uneven, and the ends of the second finger portions 2132 close to the first bus bar 11 may be flush or uneven. In the second direction, the widths of the finger portions 213 may be the same or different.

[0061] See also Figure 4 , forming a cross region A1 and non-cross regions B1 located at both ends of the cross region A1 in the first direction between the two bus bars 10. It can be understood that the area between the first finger portion 2131 and the second bus bar 12 is one of the non-cross regions B1, and the area between the second finger portion 2132 and the first bus bar 11 is another non-cross region B1.

[0062] In the same non-intersection area B1, the number of the preset areas C3 may include one, two, three or more. Figure 3 , a finger end of a finger portion 213 in the same electrode structure 21 is formed with a preset area C3, and the number of preset areas C3 is one. Exemplarily, at least two finger ends of the same electrode structure 21 are formed with a preset area, and the number of preset areas C3 is at least two. For example, see Figure 4In the second electrode structure 21b, a preset region C3 is formed at the finger end of the second finger portion 2132a, and another preset region C3 is formed at the finger end of the second finger portion 2132b, and the number of preset regions C3 is two. In some cases, in the same electrode structure 21, each finger portion 213 having a preset region C3 formed thereon may share one preset region C3; or, in the same electrode structure 21, at least two finger portions 213 each have a preset region C3 formed at their finger ends, and adjacent preset regions C3 may be connected or not connected.

[0063] See also Figure 4 Exemplarily, at least one second finger portion 2132 of the second electrode structure 21b includes a second finger portion 2132a and a second finger portion 2132b, and the area where the finger tip of the second finger portion 2132a or the second finger portion 2132b extends toward the first bus bar 11 along the first direction is defined as the first area C1, the area in the non-intersection area B1 except the first gap area B11 is the second area C2, and the area where the first area C1 and the second area C2 overlap with each other is the preset area C3, and no conductive structure is provided in the preset area C3. At least one first finger portion 2131 of the first electrode structure 21a includes a first finger portion 2131a and a first finger portion 2131b, and an area where the finger tip of the first finger portion 2131a or the finger tip of the first finger portion 2131b extends toward the second bus bar 12 along the first direction is defined as the first area C1, and an area in the non-intersection area B1 except the first gap area B11 is the second area C2, and an area where the first area C1 and the second area C2 overlap with each other is a preset area C3, and no conductive structure is provided in the preset area C3.

[0064] In some embodiments, the size of the preset area C3 in the first direction is less than or equal to 0.8λ, where λ is the wavelength of the surface acoustic wave device 1000. This is beneficial to reducing the mass at the preset area C3, increasing the sound velocity of the preset area C3, and helping to suppress the stray mode on the high-frequency side of the anti-resonance point, thereby improving the stray mode suppression effect.

[0065] See also Figure 4 In some embodiments, in the same electrode unit 20, the finger portions 213 of one electrode structure 21 are alternately arranged with the finger portions 213 of another electrode structure 21. For example, in the same electrode unit 20, the first finger portions 2131 and the second finger portions 2132 are alternately arranged in sequence along the second direction to improve the excitation coefficient of the surface acoustic wave device 1000 and effectively excite resonance.

[0066] In other embodiments, the first finger portion 2131 and the second finger portion 2132 may also be arranged in any other suitable arrangement. Figure 5In some embodiments, the finger portions 213 of the two electrode structures 21 are respectively a first finger portion 2131 and a second finger portion 2132; one of the electrode structures 21 includes a first subunit 21c, and the other electrode structure 21 includes a second subunit 21d, and the first subunit 21c and the second subunit 21d are alternately arranged along the second direction; the first subunit 21c includes at least two adjacent first finger portions 2131, and the second subunit 21d includes at least two adjacent second finger portions 2132. This structure can improve the Q value of the surface acoustic wave device 1000 and can be applied to higher frequency bands such as 5G and above. Exemplarily, the first electrode structure 21a includes a first subunit 21c, and the first subunit 21c includes at least two adjacent first finger portions 2131; the second electrode structure 21b includes a second subunit 21d, and the second subunit 21d includes at least two adjacent second finger portions 2132. The number of the first subunit 21c and the second subunit 21c can be one, two or more. For example, the number of the first finger-line parts 2131 is two, the number of the first sub-unit 21c is one, and the two first finger-line parts 2131 form one first sub-unit 21c; the number of the second finger-line parts 2132 is two, the number of the second sub-unit 21d is one, and the two second finger-line parts 2132 form one second sub-unit 21d. For another example, the number of the first finger-line parts 2131 is three, the number of the first sub-unit 21c is one, and the three first finger-line parts 2131 form one first sub-unit 21c; the number of the second finger-line parts 2132 is three, the number of the second sub-unit 21d is one, and the three second finger-line parts 2132 form one second sub-unit 21d. When there are multiple first sub-units 21c, the number of the first finger-line parts 2131 included in each first sub-unit 21c may be the same or different; when there are multiple second sub-units 21d, the number of the second finger-line parts 2132 included in each second sub-unit 21d may be the same or different.

[0067] See also Figure 5, exemplarily, the number of the first finger-bar portions 2131 and the second finger-bar portions 2132 is an even number, the number of the first finger-bar portions 2131 of the first subunit 21c is the same as the number of the second finger-bar portions 2132 of the second subunit 21d, all the first finger-bar portions 2131 form at least two first subunits 21c, and the number of the first finger-bar portions 2131 of each first subunit 21c is the same; all the second finger-bar portions 2132 form at least two second subunits 21d, and the number of the second finger-bar portions 2132 of each second subunit 21d is the same. Such a configuration can more effectively excite resonance and more effectively improve the Q value of the surface acoustic wave device 1000. For example, all first finger portions 2131 form two first subunits 21c, wherein one first subunit 21c includes adjacent first finger portions 2131a and first finger portions 2131b, and another first subunit 21c includes adjacent first finger portions 2131c and first finger portions 2131d; all second finger portions 2132 form two second subunits 21d, wherein one second subunit 21d includes adjacent second finger portions 2132a and second finger portions 2132b, and another second subunit 21d includes adjacent second finger portions 2132c and second finger portions 2132d; the first subunits 21c and the second subunits 21d are alternately arranged along the second direction. For example, refer to Figure 5 , the number of the first finger-line parts 2131 is four, the number of the first sub-units 21c is two, and two adjacent first finger-line parts 2131 form a first sub-unit 21c; the number of the second finger-line parts 2132 is four, the number of the second sub-units 21d is two, and two second finger-line parts 2132 form a second sub-unit 21d, and the two first sub-units 21c and the two second sub-units 21d are arranged alternately and spaced along the second direction. For another example, the number of the first finger-line parts 2131 is six, the number of the first sub-units 21c is three, and two adjacent first finger-line parts 2131 form a first sub-unit 21c; the number of the second finger-line parts 2132 is six, the number of the second sub-units 21d is three, and two second finger-line parts 2132 form a second sub-unit 21d; three first sub-units 21c and three second sub-units 21d are arranged alternately and spaced along the second direction. For another example, the number of the first finger-line portions 2131 is six, the number of the first sub-units 21c is two, and three adjacent first finger-line portions 2131 form a first sub-unit 21c; the number of the second finger-line portions 2132 is six, the number of the second sub-units 21d is two, and three second finger-line portions 2132 form a second sub-unit 21d; the two first sub-units 21c and the two second sub-units 21d are alternately arranged along the second direction.

[0068] In some embodiments, all first finger-line portions 2131 may form one or at least two first subunits 21c, and all second finger-line portions 2132 may form one or at least two second subunits 21d. In other embodiments, except for the first finger-line portion 2131 of the first subunit 21c and the second finger-line portion 2132 of the second subunit 21d, the remaining first finger-line portions 2131 and the remaining second finger-line portions 2132 are alternately arranged one by one.

[0069] In some embodiments, in the same electrode structure 21, the ratio of the number of finger portions 213 to the number of connecting strips 2111 is A, and A is greater than 1 and less than or equal to 8, for example, A is 2, 3, 4, 5, 6, 7, 8 or any other suitable value between 1 and 8. If A is too small, the current in the first gap region B11 will be too large, and the surface acoustic wave device 1000 will be easily burned; if A is too large, the wiring of the connecting portion 211 will be too long and easy to burn. A being within this range can effectively reduce the possibility of generating an equivalent resonant cavity in the non-intersection area B1, thereby effectively reducing the possibility of oscillation of the stray mode, and avoiding as much as possible the excitation of the acoustic wave energy leaked from the intersection area A1 to the non-intersection area B1, thereby effectively achieving the suppression of the stray mode; A being within this range can effectively reduce the mass of the connecting portion 211, and can also make the connecting portion 211 and each finger portion 213 have a suitable equivalent resistance, and make the surface acoustic wave device 1000 more reliable, and effectively reduce the problem of the surface acoustic wave device 1000 being easily burned due to excessive wiring or excessive current in the first gap area B11.

[0070] See also Figure 4 In some embodiments, in the same electrode structure 21, the number of connecting strips 2111 is one. In this way, the possibility of generating an equivalent resonant cavity in the non-intersection area B1 can be reduced as much as possible, thereby reducing the possibility of oscillation of the stray mode as much as possible, and avoiding the excitation of the acoustic wave energy leaked from the intersection area A1 to the non-intersection area B1 to the greatest extent, thereby achieving the maximum suppression of the stray mode. The number of connecting strips 2111 is one, which can reduce the mass of the connecting portion 211 as much as possible, and can also make the equivalent resistance of the connecting portion 211 and each finger portion 213 appropriate, and make the surface acoustic wave device 1000 more reliable, effectively reducing the problem of the surface acoustic wave device 1000 being easily burned due to excessive current in the first gap area B11. In other embodiments, the number of connecting strips 2111 can also be two, three or more, as long as the number of connecting strips 2111 in the same electrode structure 21 is less than the number of finger portions 213. When the number of connecting strips 2111 includes at least two, each connecting strip 2111 is arranged in an interval along the second direction.

[0071] In some embodiments, the metallization rates of the finger portions 213 and the connecting bar 2111 are ε1 and ε2 respectively, where 0.95ε1 < ε2 < 1.05ε1; and / or, the metallization rate of the connecting bar 2111 is ε2, where 0.15 < ε2 < 0.75. If ε1 and / or ε2 are too small, the resistance of the surface acoustic wave device 1000 is relatively large, resulting in the surface acoustic wave device 1000 being prone to burnout; in addition, if ε1 and / or ε2 are too small, it will also make the processing of the surface acoustic wave device 1000 difficult and not easy to process. Furthermore, if ε1 and / or ε2 are too large, the positive and negative electrodes of the surface acoustic wave device 1000 are too close to each other and are prone to breakdown; it will also cause the sound velocity to decrease and the energy suppression effect to weaken. 0.95ε1 < ε2 < 1.05ε1 makes the surface acoustic wave device 1000 highly reliable and not prone to burnout, and the surface acoustic wave device 1000 is not prone to breakdown due to the proximity of its positive and negative electrodes; and it is easy to process, has a relatively high sound velocity, and has a good energy suppression effect. Similarly, 0.15 < ε2 < 0.75 makes the surface acoustic wave device 1000 highly reliable and not prone to burnout, and the surface acoustic wave device 1000 is not prone to breakdown due to the proximity of its positive and negative electrodes; and it is easy to process, has a relatively high sound velocity, and has a good energy suppression effect.

[0072] Please refer to Figure 6 , in some embodiments, the size of the conductive portion 212 in the first direction is W1, where 0.1λ < W1 < 0.3λ, and λ is the wavelength of the surface acoustic wave device 1000. If W1 is too small, it is easy to cause the trace to burn out. If W1 is too large, the spurious mode suppression effect on the high-frequency side of the anti-resonant point will be reduced. 0.1λ < W1 < 0.3λ can balance a good spurious mode suppression effect and reliability, has a good spurious mode suppression effect on the high-frequency side of the anti-resonant point, and is not easy to cause the trace to burn out; in addition, it can also make the processing of the surface acoustic wave device 1000 easy. Exemplarily, no conductive structure is provided in the preset area C3 where the first area C1 and the second area C2 overlap. 0.1λ < W1 < 0.3λ. In this way, the spurious mode on the high-frequency side of the anti-resonant point can be more effectively suppressed, further improving the spurious mode suppression effect; and it is easy to process.

[0073] In some embodiments, the sound velocity of the first gap area B11 is greater than the sound velocity of the second gap area B12. Forming such a sound velocity distribution in the non-crossing area B1 can achieve the suppression effect of the spurious mode of the surface acoustic wave device 1000 with a higher resonant frequency, realizing a filter in the high-frequency band.

[0074] In some embodiments, the size of the second gap area B12 in the non-crossing area B1 in the first direction is less than 0.5λ, where λ is the wavelength of the surface acoustic wave device 1000. Being within this range is beneficial for restricting energy, reducing energy leakage, and increasing the Q value of the surface acoustic wave device 1000.

[0075] In some embodiments, the axis of the connecting portion 211 of one electrode structure 21 in the first direction coincides with the axis of one finger portion 213 of another electrode structure 21 in the first direction. In this way, it is ensured that the surface acoustic wave device 1000 can have an overall symmetrical electric field distribution, thereby effectively ensuring that the surface acoustic wave device 1000 has a good excitation effect and improving the performance of the surface acoustic wave device 1000. For example, please refer to Figure 4 In the first electrode structure 21a, the axis of the first connecting bar 2111a coincides with the axis of the second finger portion 2132b. In the second electrode structure 21b, the axis of the second connecting bar 2111b coincides with the axis of the first finger portion 2131b. Exemplarily, in the same electrode structure 21, the connecting bar 211 is disposed between two adjacent finger portions along the second direction.

[0076] See also Figure 6 In some embodiments, the electrode structure 21 further includes a dummy finger 214, which is connected to the bus bar 10 and is disposed in the non-crossing region B1; the dummy finger 214 and the finger end of one of the finger strip portions 213 of another electrode structure 21 are spaced apart in the first direction. The provision of the dummy finger 214 can suppress the transverse mode interference of the surface acoustic wave device 1000, reduce energy leakage, and thereby improve the Q value of the surface acoustic wave device 1000.

[0077] See also Figure 6 Exemplarily, the number of the fake fingers 214 includes a plurality of fake fingers, and the plurality of fake fingers 214 include a first fake finger 2141 and a second fake finger 2142. One end of the first fake finger 2141 is connected to the first bus bar 11, and the other end of the first fake finger 2141 is spaced apart from the finger end of the second finger portion 2132a in the first direction; one end of the second fake finger 2142 is connected to the second bus bar 12, and the other end of the second fake finger 2142 is spaced apart from the finger end of the first finger portion 2131a in the first direction. In the same electrode unit 20, the number of the first fake fingers 2141 and the number of the second fake fingers 2142 can be designed according to actual needs, such as one, two or more. Exemplarily, in the same electrode unit 20, the number of the first fake finger 2141 and the second fake finger 2142 are both one.

[0078] It can be understood that when the surface acoustic wave device 1000 is provided with a first dummy finger 2141 and a second dummy finger 2142, the first gap area B11 actually refers to the area between the first dummy finger 2141 and the first conductive portion 2121 in the first direction; or, the area between the second dummy finger 2142 and the second conductive portion 2122.

[0079] In some embodiments, the metallization rate of the dummy finger 214 is in the range of [0.25, 0.8], such as 0.25, 0.5, 0.8 or any other suitable value between 0.25 and 0.8. It is understandable that if the metallization rate of the dummy finger 214 is too small, the resistance of the surface acoustic wave device 1000 is large, causing the surface acoustic wave device 1000 to burn easily; in addition, if the metallization rate of the dummy finger 214 is too small, the surface acoustic wave device 1000 will be difficult to process and difficult to process. If the metallization rate of the dummy finger 214 is too large, the positive and negative electrodes of the surface acoustic wave device 1000 will be too close to each other and easy to break down; it will also cause the sound velocity to decrease and the energy suppression effect to weaken. The metallization rate of the dummy finger 214 is in the range of [0.25, 0.8], so that the surface acoustic wave device 1000 has high reliability and is not easy to burn out. The surface acoustic wave device 1000 is also not easy to be broken down due to the positive and negative poles being too close. It is also easy to process, has a high sound velocity, and has a good energy suppression effect.

[0080] In some embodiments, the size of the dummy finger 214 along the first direction is in the range of (0.1um, 0.5λ), where λ is the wavelength of the surface acoustic wave device 1000. The size of the dummy finger 214 along the first direction is within this range, which can better suppress the transverse mode interference of the surface acoustic wave device 1000, effectively reduce energy leakage, and thus effectively improve the Q value of the surface acoustic wave device 1000.

[0081] Exemplarily, the spacing distance between the fake finger 214 and the finger end of the corresponding finger strip portion 213 along the first direction is greater than the size of the preset area C3 along the first direction. Figure 6 The distance between the end of the first fake finger 2141 away from the first bus bar 11 and the finger end of the second finger portion 2132a along the first direction is greater than the size of the preset area C3 along the first direction.

[0082] Exemplarily, the spacing distance between the dummy finger 214 and the finger end of the corresponding finger strip portion 213 along the first direction is greater than 0.8λ, where λ is the wavelength of the surface acoustic wave device 1000. Figure 6 The distance between the end of the first dummy finger 2141 away from the first bus bar 11 and the end of the second finger portion 2132a along the first direction is greater than 0.8λ.

[0083] The number of electrode units 20 of the surface acoustic wave device 1000 may include one, two, three or more. Figure 7 , the number of electrode units 20 includes at least two, and each electrode unit 20 is disposed between two bus bars 10; in the second direction, each electrode unit 20 is disposed at intervals. Figure 7, exemplarily, the number of electrode units 20 includes at least two, and at least two electrode units 20 are arranged at intervals along the second direction; wherein the two electrode units 20 are respectively located at two lateral edges of the IDT 200 along the second direction, so as to ensure that the SAW device 1000 has a good excitation effect and improve the performance of the SAW device 1000. Exemplarily, the number of electrode units 20 includes at least two; in the same non-crossing area B1, the conductive portions 212 of each electrode unit 20 are arranged at intervals along the second direction.

[0084] In some embodiments, in addition to the finger portion 213 of the electrode unit 20, the IDT 200 does not include an electrode finger whose two ends are directly connected to the first bus bar 11 and the second bus bar 12. In other embodiments, in addition to the finger portion 213 of the electrode unit 20, the IDT 200 may also include a plurality of electrode fingers whose two ends are directly connected to the first bus bar 11 and the second bus bar 12, and the plurality of electrode fingers are alternately arranged in the second direction.

[0085] See also Figure 2 In some embodiments, the surface acoustic wave device 1000 further includes a dielectric layer 30, the dielectric layer 30 covers the IDT 200, and the dielectric layer 30 is disposed on a side of the finger portion 213 away from the piezoelectric substrate 100. The dielectric layer 30 can protect the IDT 200 and / or other components of the surface acoustic wave device 1000. The dielectric layer 30 can completely cover the IDT 200, or it can partially cover the IDT 200, for example, only covers the area where the electrode structure 21 of the IDT 200 is located, while the bus bar 10 is not covered.

[0086] In some embodiments, the dielectric layer 30 includes at least one of the following: a temperature compensation layer, a frequency modulation layer, and a passivation layer. In some embodiments, the dielectric layer 30 is a temperature compensation layer. The temperature compensation layer is used to improve the temperature characteristics of the surface acoustic wave device 1000, and the material of the temperature compensation layer can be a dielectric such as silicon oxide, silicon nitride, silicon oxynitride, etc. Among them, the material of the temperature compensation layer is usually one of the above materials, that is, the material of the temperature compensation layer is a single material. Of course, the material of the temperature compensation layer can also be a mixed material, in which case the material of the temperature compensation layer can be a mixture of any of the above materials, or a mixture of one or more of the above materials with other materials. In other embodiments, the dielectric layer 30 can also include at least one of the following: a frequency modulation layer and a passivation layer. The frequency modulation layer is used to adjust the frequency of the surface acoustic wave device 1000. The material of the frequency modulation layer can be at least one of silicon dioxide, silicon nitride, aluminum nitride, aluminum oxide, silicon oxyfluoride, silicon oxynitride, etc. The passivation layer is used to protect the interdigital transducer 200 and / or other components of the surface acoustic wave device 1000. The material of the passivation layer may be at least one of silicon dioxide, silicon nitride, aluminum nitride, aluminum oxide, silicon oxyfluoride, silicon oxynitride, and the like.

[0087] See also Figure 3 In some embodiments, the edge region A12 is provided with a low acoustic velocity portion 40, and the acoustic velocity of the region provided with the low acoustic velocity portion 40 is lower than the acoustic velocity of the middle region A11. The low acoustic velocity portion 40 can adjust the acoustic velocity of the region where the low acoustic velocity portion 40 is located, thereby adjusting the acoustic velocity distribution of the cross region A1, so that the acoustic velocity of the surface acoustic wave device 1000 can form a piston mode, thereby effectively suppressing the transverse mode and improving the performance of the surface acoustic wave device 1000. Exemplarily, the provision of the low acoustic velocity portion 40 reduces the acoustic velocity of the edge region A12; while the acoustic velocity of the second gap region B12, the acoustic velocity of the middle region A11 and the acoustic velocity of the edge region A12 are reduced in sequence, so that the second gap region B12, the middle region A11 and the edge region A12 form a piston mode, which can effectively suppress the transverse mode and improve the performance of the surface acoustic wave device 1000.

[0088] Exemplarily, the sound velocity of the second gap region B12, the sound velocity of the middle region A11, and the sound velocity of the edge region A12 decrease successively, and the second gap region B12, the middle region A11, and the edge region A12 form a piston mode; the conductive portion 212, the second gap region B12, and the edge region A12 together form a low sound velocity region, and the first gap region B11, the low sound velocity region, and the middle region A11 form another piston mode. The double piston mode can more effectively suppress the transverse mode, thereby more effectively closing the elastic wave. It can be understood that when the sound velocity of the first gap region B11 is large enough, the energy can be effectively confined in the potential well formed by the double piston mode.

[0089] Exemplarily, the low sound velocity portion 40 may include at least one of the following structures: a widened portion, a thickened portion, and a mass loading structure. Exemplarily, the widened portion is a portion of the finger strip portion 213, that is, the widened portion is a portion of the finger strip portion 213 located in the edge area A12 that is widened along the second direction compared to the portion of the finger strip portion 213 located in the middle area A11. The thickened portion is a portion of the finger strip portion 213, that is, the thickened portion is a portion of the finger strip portion 213 located in the edge area A12 that is thickened along the top-view direction compared to the portion of the finger strip portion 213 located in the middle area A11. Exemplarily, the top-view direction in this embodiment is perpendicular to the first direction and the second direction. The mass loading structure includes a mass loading block or a mass loading strip.

[0090] like Figures 8 to 11 As shown, the surface acoustic wave device 1000 according to the embodiment of the present application is compared with the surface acoustic wave device 1000 of the related art.

[0091] Figure 8 It is a comparison diagram of the admittance curves of the surface acoustic wave device 1000 of the related art and an embodiment of the present application, wherein the dotted line e1 is a schematic diagram of the admittance curve of the surface acoustic wave device 1000 of the related art; the dotted line e2 is a schematic diagram of the real part of the admittance curve of the surface acoustic wave device 1000 of the related art; the solid line d1 is a schematic diagram of the admittance curve of the surface acoustic wave device 1000 of an embodiment of the present application; and the solid line d2 is a schematic diagram of the real part of the admittance curve of the surface acoustic wave device 1000 of an embodiment of the present application. Figure 8 The horizontal axis is the frequency, in Hz; the vertical axis is the admittance, in dB. Figure 8 In the embodiment of the present application, the surface acoustic wave device 1000 includes at least two electrode units 20, and the conductive parts 212 of each electrode unit 20 are arranged at intervals in the second direction; in the same electrode structure 21, the number of connecting strips 2111 is less than the number of finger strip parts 213. Figure 8 The surface acoustic wave device 1000 of the related art includes two electrode units, and the conductive parts 212 of each electrode unit are connected together in the second direction, that is, the conductive parts 212 of each electrode unit are connected in the second direction to form a continuous and uninterrupted structure; in the same electrode structure 21, the number of connecting strips 2111 is equal to the number of finger strip parts 213. Figure 8 It can be seen that within the frequency range from F1 to F2, the heterodyne mode of the surface acoustic wave device 1000 of the embodiment of the present application is significantly reduced compared with the surface acoustic wave device 1000 of the related art.

[0092] Fig. 9It is a comparison diagram of the admittance curves of the surface acoustic wave device 1000 of the related technology and an embodiment of the present application, wherein the dotted line e3 is a schematic diagram of the admittance curve of the surface acoustic wave device 1000 of the related technology; the dotted line e4 is a schematic diagram of the real part of the admittance curve of the surface acoustic wave device 1000 of the related technology; the solid line d3 is a schematic diagram of the admittance curve of the surface acoustic wave device 1000 of an embodiment of the present application; and the solid line d4 is a schematic diagram of the real part of the admittance curve of the surface acoustic wave device 1000 of an embodiment of the present application. Fig. 9 The horizontal axis is the frequency, in Hz; the vertical axis is the admittance, in dB. Fig. 9 In the surface acoustic wave device 1000 of the embodiment of the present application, in the same electrode structure 21 , the number of the connecting strips 2111 is less than the number of the finger strip portions 213 . Fig. 9 In the surface acoustic wave device of the related art, in the same electrode structure 21, the number of the connecting strips 2111 is equal to the number of the finger strip portions 213. Fig. 9 It can be seen that when the frequency is within the frequency interval from F3 to F4, the heterodyne mode of the surface acoustic wave device 1000 of the embodiment of the present application is significantly reduced compared with the surface acoustic wave device 1000 of the related art.

[0093] Fig.10 It is a comparison diagram of the admittance curves of the surface acoustic wave device 1000 of the related technology and an embodiment of the present application, wherein the dotted line e5 is a schematic diagram of the admittance curve of the surface acoustic wave device 1000 of the related technology; the dotted line e6 is a schematic diagram of the real part of the admittance curve of the surface acoustic wave device 1000 of the related technology; the solid line d5 is a schematic diagram of the admittance curve of the surface acoustic wave device 1000 of an embodiment of the present application; and the solid line d6 is a schematic diagram of the real part of the admittance curve of the surface acoustic wave device 1000 of an embodiment of the present application. Fig.10 The horizontal axis is the frequency, in Hz; the vertical axis is the admittance, in dB. Fig.10 In the surface acoustic wave device 1000 of the embodiment of the present application, no conductive structure is provided in the preset area C3. Fig.10 In the surface acoustic wave device 1000 corresponding to the middle dotted line, a conductive structure is provided in the preset area C3. Fig.10 It can be seen that within the frequency range of F5 to F6, the heterodyne mode of the surface acoustic wave device 1000 of the embodiment of the present application is significantly reduced compared with the surface acoustic wave device 1000 of the related art.

[0094] Fig.11 It is a comparison diagram of the Q value of the surface acoustic wave device 1000 of the related art and an embodiment of the present application, wherein the dotted line e7 is a schematic diagram of the Q value of the surface acoustic wave device 1000 of the related art; the solid line d7 is a schematic diagram of the Q value of the surface acoustic wave device 1000 of an embodiment of the present application. Fig.11 The horizontal axis is frequency, the unit is Hz; the vertical axis is Q value, the unit is dB. Fig.11In the surface acoustic wave device 1000 of the embodiment of the present application, in the same electrode structure 21 , the number of the connecting strips 2111 is less than the number of the finger strip portions 213 . Fig.11 In the surface acoustic wave device of the related art, in the same electrode structure 21, the number of the connecting strips 2111 is equal to the number of the finger strip portions 213. Fig.11 It can be seen that when the frequency is in the interval frequency from F7 to F8 and in the interval frequency from F9 to F10, the Q value of the surface acoustic wave device 1000 of the embodiment of the present application is significantly improved. It can be understood that, Fig.11 The frequency corresponds to Fig. 9 The Bode image is smoothed by adjusting the frequencies in .

[0095] The embodiment of the present application also provides a surface acoustic wave device 1000, which includes a piezoelectric substrate 100 and an IDT 200, wherein the IDT 200 is disposed on the piezoelectric substrate 100; the IDT 200 includes an electrode unit 20 and two bus bars 10, wherein the two bus bars 10 are disposed opposite to each other along a first direction; the electrode unit 20 includes two electrode structures 21, wherein the two electrode structures 21 are disposed between the two bus bars 10; the two electrode structures 21 are each connected to one bus bar 10; the electrode structure 21 includes a connecting portion 211, a conductive portion 212, and a conductive portion 213. The electrode structure 21 comprises a conductive part 212 and at least two finger parts 213, the connecting part 211 comprises a connecting bar 2111, the bus bar 10 is connected to the conductive part 212 through the connecting bar 2111, and the finger parts 213 of the electrode structure 21 are connected to the conductive part 212; each finger part 213 is arranged at intervals along a second direction perpendicular to the first direction; in the first direction, there is an intersection area A1 and a non-intersection area B1 between the two bus bars 10, and the connecting part 211 and the conductive part 212 are arranged in the non-intersection area B1; in the second direction, the intersection area A1 is the area where each finger part 213 overlaps with each other. In the same electrode structure 21, the number of connecting bars 2111 is less than the number of finger parts 213, and the finger end of at least one finger part 213 of the electrode structure 21 in the first direction is not provided with a conductive structure within a preset distance from the finger end, and the preset distance is less than or equal to 0.8λ, where λ is the wavelength of the surface acoustic wave device 1000.

[0096] The surface acoustic wave device 1000 of the above-mentioned embodiment connects at least two finger portions 213 through the conductive portion 212, which can change the original periodicity of the finger portion 213, thereby weakening the stray mode; and because the number of connecting bars 2111 in the same electrode structure 21 is less than the number of finger portions 213, that is, at least two finger portions 213 connected together are connected to the bus bar 10 through connecting bars 2111 less than the number, it can reduce the possibility of generating an equivalent resonant cavity in the non-intersection area B1, thereby reducing the possibility of oscillation of the stray mode, and reducing or avoiding the probability of exciting the acoustic wave energy leaked from the intersection area A1 to the non-intersection area B1, thereby achieving the suppression of the stray mode, thereby reducing or avoiding the stray mode affecting the performance of the surface acoustic wave device 1000. In addition, since the finger end of at least one finger portion 213 of the electrode structure 21 in the first direction is not provided with a conductive structure within a preset distance from the finger end, and the preset distance is less than or equal to 0.8λ, compared with providing a conductive structure within the preset distance, the embodiment of the present application can effectively suppress the stray mode on the high-frequency side of the anti-resonance point and improve the stray mode suppression effect; the processing is simple; it is conducive to saving the use of conductive materials, thereby facilitating the lightweighting of the product and reducing costs.

[0097] For example, see Figure 4 At least one second finger portion 2132 of the second electrode structure 21b includes a second finger portion 2132a, and the finger end of the second finger portion 2132a is not provided with a conductive structure within a preset distance from the finger end, and the area corresponding to the preset distance is located in the non-intersection area B1. At least one first finger portion 2131 of the first electrode structure 21a includes a first finger portion 2131a, and the finger end of the first finger portion 2131a is not provided with a conductive structure within a preset distance from the finger end, and the area corresponding to the preset distance is located in the non-intersection area B1.

[0098] See also Figure 3 In some embodiments, the non-intersection area B1 includes a first gap area B11, which is an area between the busbar 10 and the conductive portion 212, and defines an area where the finger tip of at least one finger portion 213 of the electrode structure 21 extends toward the busbar 10 connected to another electrode structure 21 along the first direction as the first area C1, and the area other than the first gap area B11 in the non-intersection area B1 is the second area C2, and the area where the first area C1 and the second area C2 overlap is the preset area C3; no conductive structure is provided in the preset area C3. Since no conductive structure is provided in the preset area C3 where the first area C1 and the second area C2 overlap, compared with the case where a conductive structure is provided in the preset area C3, the embodiment of the present application can effectively suppress the stray mode on the high-frequency side of the anti-resonance point, and improve the stray mode suppression effect; the processing is simple; it is conducive to saving the use of conductive materials, thereby facilitating the lightweighting of the product and reducing the cost.

[0099] In addition, the configuration of the piezoelectric substrate 1 and the interdigital transducer 2 in this embodiment is the same as that of the above embodiments, and will not be described in detail in this embodiment.

[0100] The embodiment of the present application also provides a surface acoustic wave device 1000, which includes a piezoelectric substrate 100 and an IDT 200, wherein the IDT 200 is disposed on the piezoelectric substrate 100; the IDT 200 includes an electrode unit 20 and two bus bars 10, wherein the two bus bars 10 are disposed opposite to each other along a first direction; the electrode unit 20 includes two electrode structures 21, wherein the two electrode structures 21 are disposed between the two bus bars 10; the two electrode structures 21 are each connected to one bus bar 10; the electrode structure 21 includes a connecting portion 211, a conductive portion 212, and a conductive portion 213. The connecting portion 211 includes a connecting bar 2111, the bus bar 10 is connected to the conductive portion 212 through the connecting bar 2111, and the finger portion 213 of the electrode structure 21 is connected to the conductive portion 212; the finger portions 213 are arranged at intervals along a second direction perpendicular to the first direction; in the first direction, there is an intersection area A1 and a non-intersection area B1 between the two bus bars 10, and the connecting portion 211 and the conductive portion 212 are arranged in the non-intersection area B1; in the second direction, the intersection area A1 is an area where the finger portions 213 overlap each other. Among them, in the same electrode structure 21, the number of connecting strips 2111 is less than the number of finger-bar portions 213; the finger-bar portions 213 of the two electrode structures 21 are respectively the first finger-bar portion 2131 and the second finger-bar portion 2132, wherein one electrode structure 21 includes a first sub-unit 21c, and the other electrode structure 21 includes a second sub-unit 21d, and the first sub-unit 21c and the second sub-unit 21d are alternately arranged along the second direction; the first sub-unit 21c includes at least two adjacent first finger-bar portions 2131, and the second sub-unit 21d includes at least two adjacent second finger-bar portions 2132.

[0101] The surface acoustic wave device 1000 of the above-mentioned embodiment connects at least two finger portions 213 through the conductive portion 212, which can change the original periodicity of the finger portion 213, thereby weakening the stray mode; and because the number of connecting bars 2111 in the same electrode structure 21 is less than the number of finger portions 213, that is, at least two finger portions 213 connected together are connected to the bus bar 10 through connecting bars 2111 less than the number, it can reduce the possibility of generating an equivalent resonant cavity in the non-intersection area B1, thereby reducing the possibility of oscillation of the stray mode, and reducing or avoiding the probability of exciting the acoustic wave energy leaked from the intersection area A1 to the non-intersection area B1, thereby achieving the suppression of the stray mode, thereby reducing or avoiding the stray mode affecting the performance of the surface acoustic wave device 1000. In addition, since one of the electrode structures 21 includes a first subunit 21c and the other electrode structure 21 includes a second subunit 21d, the first subunit 21c and the second subunit 21d are arranged alternately along the second direction; the first subunit 21c includes at least two adjacent first finger portions 2131, and the second subunit 21d includes at least two adjacent second finger portions 2132, thereby being able to improve the Q value of the surface acoustic wave device 1000 and being applicable to higher frequency bands such as 5G and above.

[0102] See also Figure 3 In some embodiments, the non-intersection area B1 includes a first gap area B11, which is an area between the busbar 10 and the conductive portion 212, and defines an area where the finger tip of at least one finger portion 213 of the electrode structure 21 extends toward the busbar 10 connected to another electrode structure 21 along the first direction as the first area C1, and the area other than the first gap area B11 in the non-intersection area B1 is the second area C2, and the area where the first area C1 and the second area C2 overlap is the preset area C3; no conductive structure is provided in the preset area C3. Since no conductive structure is provided in the preset area C3 where the first area C1 and the second area C2 overlap, compared with the case where a conductive structure is provided in the preset area C3, the embodiment of the present application can effectively suppress the stray mode on the high-frequency side of the anti-resonance point, and improve the stray mode suppression effect; the processing is simple; it is conducive to saving the use of conductive materials, thereby facilitating the lightweighting of the product and reducing the cost.

[0103] In addition, the configuration of the piezoelectric substrate 1 and the interdigital transducer 2 in this embodiment is the same as that of the above embodiments, and will not be described in detail in this embodiment.

[0104] The embodiment of the present application also provides a surface acoustic wave device 1000, which includes a piezoelectric substrate 100 and an IDT 200, wherein the IDT 200 is disposed on the piezoelectric substrate 100; the IDT 200 includes an electrode unit 20 and two bus bars 10, wherein the two bus bars 10 are disposed opposite to each other along a first direction; the electrode unit 20 includes two electrode structures 21, wherein the two electrode structures 21 are disposed between the two bus bars 10; the two electrode structures 21 are each connected to one bus bar 10; the electrode structure 21 includes a connecting portion 211, a conductive portion 212, and a conductive portion 213. The electrode structure 21 comprises a conductive part 212 and at least two finger parts 213, the connecting part 211 comprises a connecting bar 2111, the bus bar 10 is connected to the conductive part 212 through the connecting bar 2111, and the finger parts 213 of the electrode structure 21 are connected to the conductive part 212; each finger part 213 is arranged at intervals along a second direction perpendicular to the first direction; in the first direction, there is an intersection area A1 and a non-intersection area B1 between the two bus bars 10, and the connecting part 211 and the conductive part 212 are arranged in the non-intersection area B1; in the second direction, the intersection area A1 is the area where each finger part 213 overlaps with each other. In the same electrode structure 21, the number of connecting bars 2111 is less than the number of finger parts 213, and the ratio of the number of finger parts 213 to the number of connecting bars 2111 is A, and A is greater than 1 and less than or equal to 8.

[0105] The surface acoustic wave device 1000 of the above-mentioned embodiment connects at least two finger portions 213 through the conductive portion 212, which can change the original periodicity of the finger portion 213, thereby weakening the stray mode; and because the number of connecting bars 2111 in the same electrode structure 21 is less than the number of finger portions 213, that is, at least two finger portions 213 connected together are connected to the bus bar 10 through connecting bars 2111 less than the number, it can reduce the possibility of generating an equivalent resonant cavity in the non-intersection area B1, thereby reducing the possibility of oscillation of the stray mode, and reducing or avoiding the probability of exciting the acoustic wave energy leaked from the intersection area A1 to the non-intersection area B1, thereby achieving the suppression of the stray mode, thereby reducing or avoiding the stray mode affecting the performance of the surface acoustic wave device 1000. In addition, since the ratio A of the number of finger portions 213 to the number of connecting strips 2111 is greater than 1 and less than or equal to 8, the possibility of generating an equivalent resonant cavity in the non-intersection area B1 can be effectively reduced, thereby effectively reducing the possibility of oscillation of the stray mode, and avoiding as much as possible the excitation of the acoustic wave energy leaked from the intersection area A1 to the non-intersection area B1, thereby effectively achieving the suppression of the stray mode; in addition, A is within this range, which can effectively reduce the mass of the connecting portion 211, and can also make the connecting portion 211 and each finger portion 213 have a suitable equivalent resistance, and make the surface acoustic wave device 1000 more reliable, and effectively reduce the problem of the surface acoustic wave device 1000 being easily burned due to excessive current in the first gap area B11.

[0106] See also Figure 3In some embodiments, the non-intersection area B1 includes a first gap area B11, which is an area between the busbar 10 and the conductive portion 212, and defines an area where the finger tip of at least one finger portion 213 of the electrode structure 21 extends toward the busbar 10 connected to another electrode structure 21 along the first direction as the first area C1, and the area other than the first gap area B11 in the non-intersection area B1 is the second area C2, and the area where the first area C1 and the second area C2 overlap is the preset area C3; no conductive structure is provided in the preset area C3. Since no conductive structure is provided in the preset area C3 where the first area C1 and the second area C2 overlap, compared with the case where a conductive structure is provided in the preset area C3, the embodiment of the present application can effectively suppress the stray mode on the high-frequency side of the anti-resonance point, and improve the stray mode suppression effect; the processing is simple; it is conducive to saving the use of conductive materials, thereby facilitating the lightweighting of the product and reducing the cost.

[0107] In addition, the configuration of the piezoelectric substrate 1 and the interdigital transducer 2 in this embodiment is the same as that of the above embodiments, and will not be described in detail in this embodiment.

[0108] An embodiment of the present application further provides a filter, comprising the surface acoustic wave device 1000 of any one of the above embodiments.

[0109] Exemplarily, the filter includes a plurality of surface acoustic wave devices 1000, wherein at least one surface acoustic wave device 1000 includes the surface acoustic wave device 1000 of any of the above embodiments. The structures of the surface acoustic wave devices 1000 may be the same or different, which is not limited here.

[0110] An embodiment of the present application also provides a radio frequency front-end module, comprising the surface acoustic wave device 1000 of any one of the above embodiments.

[0111] In some embodiments, the RF front-end module can be applied to electronic devices, which may include but are not limited to LED panels, tablet computers, notebooks, computers, navigators, mobile phones, electronic watches and other electronic devices or components with PCBs, and this application does not impose any restrictions on this.

[0112] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "mechanically coupled" and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be directly connected or indirectly connected through an intermediate medium. It can be the internal connection of two elements or the interaction relationship between two elements. The mechanical coupling or coupling of two components includes direct coupling and indirect coupling, for example, direct fixed connection, connection through a transmission mechanism, etc. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0113] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0114] The disclosure above provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described above. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the various specific processes and material examples provided by the present application, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0115] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific method steps, features, structures, materials, or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific method steps, features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0116] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A surface acoustic wave device, characterized in that: The surface acoustic wave device comprises a piezoelectric substrate and an interdigital transducer, wherein the interdigital transducer is arranged on the piezoelectric substrate; the interdigital transducer comprises: Two bus bars, the two bus bars are arranged opposite to each other at an interval along a first direction; An electrode unit, comprising two electrode structures, wherein the two electrode structures are arranged between the two bus bars; the two electrode structures are each connected to one bus bar; the electrode structure comprises a connecting portion, a conductive portion and at least two finger portions, the connecting portion comprises a connecting bar, the bus bar is connected to the conductive portion via the connecting bar, and the finger portion of the electrode structure is connected to the conductive portion; the finger portions are arranged at intervals along a second direction perpendicular to the first direction; in the first direction, there are a crossing area and a non-crossing area between the two bus bars, the connecting portion and the conductive portion are arranged in the non-crossing area; in the second direction, the crossing area is an area where the finger portions overlap each other; Among them, in the same electrode structure, the number of the connecting strips is less than the number of the finger strip portions; the non-intersection area includes a first gap area, the first gap area is the area between the bus bar and the conductive part, and the area where the finger tip of at least one finger strip portion of the electrode structure extends along the first direction toward the bus bar connected to another electrode structure is defined as the first area, the area in the non-intersection area other than the first gap area is the second area, and the area where the first area and the second area overlap with each other is the preset area; no conductive structure is provided in the preset area.

2. The surface acoustic wave device according to claim 1, characterized in that: The size of the preset area in the first direction is less than or equal to 0.8λ, where λ is the wavelength of the surface acoustic wave device.

3. The surface acoustic wave device according to claim 1, characterized in that: The finger portions of the two electrode structures are respectively a first finger portion and a second finger portion; one of the electrode structures includes a first sub-unit, and the other electrode structure includes a second sub-unit, and the first sub-units and the second sub-units are arranged alternately along the second direction; the first sub-unit includes at least two adjacent first finger portions, and the second sub-unit includes at least two adjacent second finger portions.

4. The surface acoustic wave device according to claim 3, characterized in that: The number of the first finger parts and the second finger parts is an even number, the number of the first finger parts of the first sub-unit is the same as the number of the second finger parts of the second sub-unit, all of the first finger parts form at least two of the first sub-units, and the number of the first finger parts of each of the first sub-units is the same; all of the second finger parts form at least two of the second sub-units, and the number of the second finger parts of each of the second sub-units is the same.

5. The surface acoustic wave device according to claim 1, characterized in that: In the same electrode unit, the finger-line portions of one electrode structure and the finger-line portions of another electrode structure are arranged alternately and spaced apart.

6. The surface acoustic wave device according to claim 1, characterized in that: In the same electrode structure, the ratio of the number of the finger strips to the number of the connecting strips is A, and A is greater than 1 and less than or equal to 8.

7. The surface acoustic wave device according to claim 1, characterized in that: In the same electrode structure, the number of the connecting strip is one.

8. The surface acoustic wave device according to any one of claims 1 to 7, characterized in that: The metallization rates of the finger strip portion and the connecting strip are ε1 and ε2 respectively, 0.95ε1<ε2<1.05ε1; and / or, The metallization rate of the connection bar is ε2, where 0.15 < ε2 < 0.

75.

9. The surface acoustic wave device according to any one of claims 1 to 7, characterized in that: The size of the conductive part in the first direction is W1, where 0.1λ < W1 < 0.3λ, and λ is the wavelength of the surface acoustic wave device.

10. The surface acoustic wave device according to any one of claims 1 to 7, characterized in that: The non-crossing area includes a first gap area and a second gap area. The first gap area is the area between the bus bar and the conductive part, and the second gap area is the area between the crossing area and the conductive part. The sound velocity in the first gap area is greater than that in the second gap area.

11. The surface acoustic wave device according to any one of claims 1 to 7, characterized in that: The non-crossing area includes a second gap area, which is the area between the crossing area and the conductive part. The size of the second gap area in the first direction is less than 0.5λ, where λ is the wavelength of the surface acoustic wave device.

12. The surface acoustic wave device according to any one of claims 1 to 7, characterized in that: The axis of the connection part of one of the electrode structures in the first direction coincides with the axis of one of the finger bar parts of the other electrode structure in the first direction.

13. The surface acoustic wave device according to any one of claims 1 to 7, characterized in that: The electrode structure further includes: Dummy fingers, connected to the bus bar and provided in the non-crossing area; the dummy fingers are spaced from the finger tip of one of the finger bar parts of the other electrode structure in the first direction.

14. The surface acoustic wave device according to claim 13, characterized in that: The metallization rate range of the dummy fingers is [0.25, 0.8]; and / or, The size range of the dummy fingers in the first direction is (0.1um, 0.5λ), where λ is the wavelength of the surface acoustic wave device.

15. The surface acoustic wave device according to any one of claims 1 to 7, characterized in that: The number of the electrode units includes at least two, and at least two electrode units are spaced along the second direction; two of the electrode units are respectively located at two lateral edges of the interdigital transducer along the second direction.

16. The surface acoustic wave device according to claim 1, characterized in that: It further includes: A dielectric layer, which covers the interdigital transducer and is provided on the side of the finger bar part away from the piezoelectric substrate.

17. The surface acoustic wave device according to claim 16, characterized in that: The dielectric layer includes at least one of the following: a temperature compensation layer, a frequency modulation layer, and a passivation layer.

18. The surface acoustic wave device according to claim 1, characterized in that: The piezoelectric substrate includes a piezoelectric thin film and a substrate stacked, and the interdigital transducer is provided on the surface of the piezoelectric thin film away from the substrate.

19. The surface acoustic wave device according to claim 1, characterized in that: The crossing area includes an intermediate area and edge areas on both sides of the intermediate area. The edge areas are provided with low sound velocity parts, and the sound velocity in the area where the low sound velocity parts are provided is less than that in the intermediate area.

20. A surface acoustic wave device, characterized in that: The surface acoustic wave device includes a piezoelectric substrate and an interdigital transducer, and the interdigital transducer is provided on the piezoelectric substrate; the interdigital transducer includes: Two bus bars, which are spaced and oppositely arranged along the first direction; Electrode units, including two electrode structures, which are provided between the two bus bars; each of the two electrode structures is connected to one of the bus bars; the electrode structure includes a connection part, a conductive part, and at least two finger bar parts. The connection part includes a connection bar, and the bus bar is connected to the conductive part through the connection bar. The finger bar parts of the electrode structure are connected to the conductive part; each of the finger bar parts is arranged at intervals along a second direction perpendicular to the first direction; in the first direction, there is a crossing area and a non-crossing area between the two bus bars, and the connection part and the conductive part are provided in the non-crossing area; in the second direction, the crossing area is the area where the finger bar parts overlap each other; Among them, in the same electrode structure, the number of the connecting strips is less than the number of the finger strip portions, and the finger end of at least one finger strip portion of the electrode structure in the first direction is not provided with a conductive structure within a preset distance from the finger end, and the preset distance is less than or equal to 0.8λ, where λ is the wavelength of the surface acoustic wave device.

21. A surface acoustic wave device, characterized in that: The surface acoustic wave device comprises a piezoelectric substrate and an interdigital transducer, wherein the interdigital transducer is arranged on the piezoelectric substrate; the interdigital transducer comprises: Two bus bars, the two bus bars are arranged opposite to each other at an interval along a first direction; An electrode unit, comprising two electrode structures, wherein the two electrode structures are arranged between the two bus bars; the two electrode structures are each connected to one bus bar; the electrode structure comprises a connecting portion, a conductive portion and at least two finger portions, the connecting portion comprises a connecting bar, the bus bar is connected to the conductive portion via the connecting bar, and the finger portion of the electrode structure is connected to the conductive portion; the finger portions are arranged at intervals along a second direction perpendicular to the first direction; in the first direction, there are a crossing area and a non-crossing area between the two bus bars, the connecting portion and the conductive portion are arranged in the non-crossing area; in the second direction, the crossing area is an area where the finger portions overlap each other; Among them, in the same electrode structure, the number of the connecting strips is less than the number of the finger strip portions; the finger strip portions of the two electrode structures are respectively a first finger strip portion and a second finger strip portion, one of the electrode structures includes a first sub-unit, and the other electrode structure includes a second sub-unit, and the first sub-unit and the second sub-unit are alternately arranged along the second direction; the first sub-unit includes at least two adjacent first finger strip portions, and the second sub-unit includes at least two adjacent second finger strip portions.

22. A surface acoustic wave device, characterized in that: The surface acoustic wave device comprises a piezoelectric substrate and an interdigital transducer, wherein the interdigital transducer is arranged on the piezoelectric substrate; the interdigital transducer comprises: Two bus bars, the two bus bars are arranged opposite to each other at an interval along a first direction; An electrode unit, comprising two electrode structures, wherein the two electrode structures are arranged between the two bus bars; the two electrode structures are each connected to one bus bar; the electrode structure comprises a connecting portion, a conductive portion and at least two finger portions, the connecting portion comprises a connecting bar, the bus bar is connected to the conductive portion via the connecting bar, and the finger portion of the electrode structure is connected to the conductive portion; the finger portions are arranged at intervals along a second direction perpendicular to the first direction; in the first direction, there are a crossing area and a non-crossing area between the two bus bars, the connecting portion and the conductive portion are arranged in the non-crossing area; in the second direction, the crossing area is an area where the finger portions overlap each other; Among them, in the same electrode structure, the number of the connecting bars is less than the number of the finger portions, and the ratio of the number of the finger portions to the number of the connecting bars is A, and A is greater than 1 and less than or equal to 8.

23. A filter, characterized in that: Comprising the surface acoustic wave device as described in any one of claims 1-22.

24. A radio frequency front-end module, characterized in that: Comprising the surface acoustic wave device as described in any one of claims 1-22.

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