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, an interdigital transducer and an accessory structure, and the interdigital transducer is arranged on the piezoelectric substrate; in the arrangement direction of two bus bars of the interdigital transducer, an intersection area is arranged between the two bus bars, and the intersection area comprises a middle area and edge areas located at the two ends of the middle area; wherein in the arrangement direction of the electrode fingers of the interdigital transducer, the intersection area is an area where the electrode fingers are mutually overlapped; each electrode finger comprises a widened part located in the edge area; the accessory structure is located in the edge area; wherein in the same edge area, the projections of the widened part and the accessory structure in the overlook direction are at least partially staggered along the length extension direction of the electrode fingers, and the acoustic impedance of the area provided with the widened part is different from the acoustic impedance of the area provided with the accessory structure. According to the surface acoustic wave device, the filter and the radio frequency front-end module, a high-order transverse mode and a low-order transverse mode can be well inhibited.

Description

TECHNICAL FIELD

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

[0002] A surface acoustic wave device processes an acoustic signal propagating on a surface of a piezoelectric substrate by using a feature of an acoustic-electric transducer. The surface acoustic wave device has advantages of low cost, small size and multiple functions, and thus is widely applied in fields of radar, communication, navigation and identification. The surface acoustic wave device includes an interdigital transducer (IDT) which can convert an electric signal into an acoustic signal or convert an acoustic signal into an electric signal. A transverse mode of the surface acoustic wave device causes acoustic wave leakage, thereby causing acoustic energy loss and reducing a quality factor value. However, the surface acoustic wave device in the related art has an unreasonable structure design, and the suppression effect on the transverse mode of the surface acoustic wave device is not ideal. SUMMARY

[0003] The present application provides a surface acoustic wave device, a filter and a radio frequency front-end module, and aims to better suppress high-order transverse modes and low-order transverse modes.

[0004] The present application provides a surface acoustic wave device, which comprises:

[0005] a piezoelectric substrate;

[0006] an interdigital transducer arranged on the piezoelectric substrate; in a direction in which two bus bars of the interdigital transducer are arranged, the two bus bars have a crossing area between them, the crossing area includes a middle area and edge areas located at two ends of the middle area; in a direction in which each electrode finger of the interdigital transducer is arranged, the crossing area is an area in which each electrode finger overlaps with each other; the electrode finger includes a widened part located in the edge area;

[0007] an auxiliary structure located in the edge area;

[0008] In the same edge area, a projection of the widened part and the auxiliary structure in a top view direction is arranged at least partially staggered along a length extension direction of the electrode finger, and an acoustic impedance of an area provided with the widened part is different from an acoustic impedance of an area provided with the auxiliary structure.

[0009] The present application further provides a surface acoustic wave device, which comprises:

[0010] a piezoelectric substrate;

[0011] The interdigital transducer is arranged on the piezoelectric substrate; in the arrangement direction of two bus bars of the interdigital transducer, the two bus bars have a crossing area between them, the crossing area includes a middle area and edge areas located at both ends of the middle area; in the arrangement direction of each electrode finger of the interdigital transducer, the crossing area is an area in which each electrode finger overlaps with each other; the electrode finger includes a widened part located in the edge area;

[0012] The accessory structure is arranged in at least one of the two edge areas.

[0013] In the same edge area, the projection of the widened part and the accessory structure in the top view direction is at least partially staggered in the length extension direction of the electrode finger.

[0014] The accessory structure is a conductive structure, the accessory structure includes a plurality of accessory blocks, each accessory block is arranged in sequence and is spaced apart in the arrangement direction of each electrode finger; in the top view direction, each electrode finger is arranged in conjunction with an accessory block.

[0015] The medium layer is arranged on the piezoelectric substrate and covers the interdigital transducer and the accessory structure.

[0016] The embodiment of the present application also provides a surface acoustic wave device, which comprises:

[0017] The piezoelectric substrate;

[0018] The interdigital transducer is arranged on the piezoelectric substrate; in the arrangement direction of two bus bars of the interdigital transducer, the two bus bars have a crossing area between them, the crossing area includes a middle area and edge areas located at both ends of the middle area; in the arrangement direction of each electrode finger of the interdigital transducer, the crossing area is an area in which each electrode finger overlaps with each other; the electrode finger includes a widened part located in the edge area.

[0019] The accessory structure is arranged in at least one of the two edge areas.

[0020] In the same edge area, the projection of the widened part and the accessory structure in the top view direction is at least partially staggered in the length extension direction of the electrode finger; the accessory structure is a non-conductive structure; in the top view direction, a medium layer is arranged between the accessory structure and the interdigital transducer.

[0021] The embodiment of the present application also provides a surface acoustic wave device, which comprises:

[0022] The piezoelectric substrate;

[0023] The interdigital transducer is arranged on the piezoelectric substrate; in the arrangement direction of two bus bars of the interdigital transducer, the two bus bars have a crossing area between them, the crossing area includes a middle area and edge areas located at both ends of the middle area; in the arrangement direction of each electrode finger of the interdigital transducer, the crossing area is an area in which each electrode finger overlaps with each other; the electrode finger includes a widened part located in the edge area;

[0024] An auxiliary structure is located in the edge area, the auxiliary structure includes a first area, a second area and a third area, in the length extension direction of the electrode finger, the first area and the third area are respectively located on the two sides away from the second area;

[0025] In the same edge area, the auxiliary structure covers the widened part, and the projection of the second area in the top view direction overlaps with the widened part along the length extension direction of the electrode finger.

[0026] Embodiments of the present application also provide a surface acoustic wave device, which comprises:

[0027] A piezoelectric substrate;

[0028] An interdigital transducer arranged on the piezoelectric substrate; in the arrangement direction of two bus bars of the interdigital transducer, the two bus bars have a crossing area between them, the crossing area includes a middle area and edge areas located at both ends of the middle area; in the arrangement direction of each electrode finger of the interdigital transducer, the crossing area is an area in which each electrode finger overlaps with each other; the electrode finger includes a widened part located in the edge area;

[0029] An auxiliary structure is located in the edge area;

[0030] In the same edge area, the auxiliary structure covers the widened part, and the projection of the second area in the top view direction overlaps with the widened part along the length extension direction of the electrode finger.

[0031] In the same edge area, the auxiliary structure covers the widened part, and the projection of the second area in the top view direction overlaps with the widened part along the length extension direction of the electrode finger.

[0032] Embodiments of the present application also provide a filter comprising the surface acoustic wave device according to any one of the above.

[0033] Embodiments of the present application also provide a radio frequency front end module comprising the surface acoustic wave device according to any one of the above.

[0034] The surface acoustic wave device, the filter and the radio frequency front-end module provided by the embodiments of the present application have the following advantages: the projection of the widened part and the auxiliary structure in the top view direction is arranged at least partially staggered along the length extension direction of the electrode finger at the same edge area of the interdigital transducer of the surface acoustic wave device; the acoustic impedance of the area provided with the widened part is different from the acoustic impedance of the area provided with the auxiliary structure in the same edge area, the projection of the widened part and the auxiliary structure in the top view direction is arranged at least partially staggered along the length extension direction of the electrode finger in the same edge area, so as to adjust the acoustic impedance of the edge area, so that the acoustic impedance of the area provided with the widened part is different from the acoustic impedance of the area provided with the auxiliary structure, so that the surface acoustic wave device can better suppress the high-order transverse mode and the low-order transverse mode, so as to effectively suppress the transverse mode of the surface acoustic wave device, and reduce the adverse effects of the transverse mode on the surface acoustic wave device as much as possible, and effectively prevent energy leakage.

[0035] It should be understood that the general description above and the detailed description below are only exemplary and explanatory, and cannot limit the disclosure of the embodiments of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0037] Figure 1 is a structural schematic diagram of a surface acoustic wave device provided by an embodiment of the present application;

[0038] Figure 2 is a structural schematic diagram of a surface acoustic wave device provided by an embodiment of the present application;

[0039] Figure 3 is a partial structural schematic diagram of a surface acoustic wave device provided by an embodiment of the present application;

[0040] Figure 4 is a partial structural schematic diagram of a surface acoustic wave device provided by an embodiment of the present application;

[0041] Figure 5 is a partial structural schematic diagram of a surface acoustic wave device provided by an embodiment of the present application;

[0042] Figure 6 is a partial structural schematic diagram of a surface acoustic wave device provided by an embodiment of the present application;

[0043] Figure 7Figure 1 is a partial structural schematic diagram of a surface acoustic wave device provided by an embodiment of the present application;

[0044] Figure 8 Figure 2 is a partial structural schematic diagram of a surface acoustic wave device provided by an embodiment of the present application;

[0045] Figure 9 Figure 3 is a partial structural schematic diagram of a surface acoustic wave device provided by an embodiment of the present application;

[0046] Figure 10 Figure 4 is a partial structural schematic diagram of a surface acoustic wave device provided by an embodiment of the present application;

[0047] Figure 11 Figure 5 is a partial structural schematic diagram of a surface acoustic wave device provided by an embodiment of the present application;

[0048] Figure 12 Figures (a) and (b) are partial structural schematic diagrams of surface acoustic wave devices provided by different embodiments of the present application, respectively; Figure 12

[0049] Figure 12 Figures (c)-(f) are structural schematic diagrams of widening portions provided by different embodiments of the present application, respectively;

[0050] Figure 13 Figure 6 is a partial structural schematic diagram of a surface acoustic wave device provided by an embodiment of the present application;

[0051] Figure 14 Figure 7 is a plot of an admittance curve of a surface acoustic wave device of Comparative Example 1;

[0052] Figure 15 Figure 8 is a plot of an admittance curve of a surface acoustic wave device of Comparative Example 2;

[0053] Figure 16 Figure 9 is a plot of an admittance curve of a surface acoustic wave device provided by an embodiment of the present application;

[0054] Figure 17 Figure 10 is a plot of a comparison of the real part of the admittance of a surface acoustic wave device provided by an embodiment of the present application and a surface acoustic wave device of a comparative example.

[0055] Legend of Reference Signs:

[0056] 1000, surface acoustic wave device;

[0057] 100, piezoelectric substrate; 101, substrate; 102, piezoelectric thin film;

[0058] 200, interdigital transducer;

[0059] 10, bus bar; 11, first bus bar; 12, second bus bar;

[0060] ​20, electrode finger; 201, first electrode finger; 202, second electrode finger; 21, widening;

[0061] 30, artificial finger; 31, first artificial finger; 32, second artificial finger;

[0062] 300, reflecting structure; 400, accessory structure; 401, accessory block; 500, dielectric layer;

[0063] A1, intersection region; A11, intermediate region; A12, edge region; B1, gap region. DETAILED DESCRIPTION

[0064] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0065] In the description of the present application, it should be understood that the terms “center”, “longitudinal”, “transverse”, “length”, “width”, “thickness”, “upper”, “lower”, “front”, “rear”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer”, “clockwise”, “counterclockwise” and the like indicate the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms “first” and “second” are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by “first” and “second” can 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 specifically limited.

[0066] It should also be understood that the terms used in the present application specification are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the present application specification and the appended claims, unless otherwise clearly indicated by the context, the singular forms “a”, “an” and “the” are intended to include the plural forms.

[0067] It should be further understood that the term “and / or” used in the present application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0068] Some embodiments of the present application will be described in detail with reference to the drawings. The following embodiments and features of the embodiments described below can be combined with each other without conflict.

[0069] Please refer to Figure 1 and Figure 2 , the embodiment of the present application provides a surface acoustic wave device 1000, including a piezoelectric substrate 100 and an interdigital transducer 200, the interdigital transducer 200 is arranged on the piezoelectric substrate 100. The interdigital transducer 200 and the piezoelectric substrate 100 can convert electrical signals into acoustic waves or convert acoustic waves into electrical signals. Exemplarily, the surface acoustic wave device 1000 can further include a reflective structure 300, the reflective structure 300 can be arranged on the opposite sides of the interdigital transducer 200. Specifically, in the direction of acoustic wave propagation, the reflective structure 300 is arranged on the opposite sides of the interdigital transducer 200. The reflective structure 300 is used to reflect acoustic waves and limit acoustic waves in the area where the interdigital transducer 200 is located.

[0070] Exemplarily, the surface acoustic wave device 1000 can include a surface acoustic wave resonator. The surface acoustic wave resonator can 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, a transversely excited film bulk acoustic resonator, etc.

[0071] In some embodiments, the material of the piezoelectric substrate 100 can specifically include at least one of quartz, aluminum nitride, sapphire, LN (lithium niobate, LiNbO3), LT (lithium tantalate, LiTaO3), etc., which is not limited herein.

[0072] In some embodiments, the material of the interdigital transducer 200 can be a single metal material or a composite or alloy material of different metals. Optionally, the material of the interdigital transducer 200 can be one of aluminum, molybdenum, copper, gold, platinum, silver, nickel, chromium, tungsten, etc., or a composite or alloy thereof.

[0073] Please refer to Figure 2 and Figure 3 , the interdigital transducer 200 includes a bus bar 10 and an electrode finger 20. The number of bus bars 10 includes two. In the arrangement direction of the two bus bars 10 of the interdigital transducer 200, the two bus bars 10 have a crossing area A1 therebetween. The crossing area A1 includes a middle area A11 and an edge area A12 located on both sides of the middle area A11. In the arrangement direction of each electrode finger 20 of the interdigital transducer 200, the crossing area A1 is an area where each electrode finger 20 overlaps with each other.

[0074] Exemplarily, the bus bars 10 and the electrode fingers 20 can be prepared simultaneously in one process or prepared in different processes, which is not specifically limited in the embodiment.

[0075] Referring to Figure 3 In some embodiments, the two bus bars 10 are a first bus bar 11 and a second bus bar 12, which are arranged along a first direction on the piezoelectric substrate 100, and the first bus bar 11 and the second bus bar 12 are respectively connected with a plurality of electrode fingers 20. Each electrode finger 20 includes a first electrode finger 201 and a second electrode finger 202, the first electrode finger 201 is connected with the first bus bar 11, and the second electrode finger 202 is connected with the second bus bar 12. The first electrode finger 201 and the second electrode finger 202 are arranged along a second direction. The first direction is perpendicular to the second direction. Exemplarily, the first electrode finger 201 and the second electrode finger 202 are arranged along the second direction in turn and staggered. Exemplarily, the first direction is perpendicular to the second direction refers to that the first direction is perpendicular to the second direction in the plane of the piezoelectric substrate 100. Exemplarily, the first direction is the arrangement direction of the two bus bars 10 or the length extension direction of the electrode fingers 20, and the second direction is the sound wave propagation direction or the arrangement direction of the electrode fingers 20. Exemplarily, the first direction or the arrangement direction of the two bus bars 10 is as shown by the X direction in Figure 3 , and the second direction or the arrangement direction of the electrode fingers 20 is as shown by the Y direction in Figure 3 .

[0076] Exemplarily, the top view direction in the embodiment is perpendicular to the first direction and the second direction. Exemplarily, the interdigital transducer 200 is arranged on the upper surface of the piezoelectric substrate 100, and the “top view direction” refers to the direction of viewing the piezoelectric substrate 100 from top to bottom along the direction perpendicular to the upper surface of the piezoelectric substrate 100. The meaning of the term “top view direction” is the same in each embodiment, which will not be repeated in subsequent embodiments.

[0077] In other embodiments, the length direction of the bus bar 10 can also intersect with the second direction, as long as it is not parallel to the first direction. The length direction of each electrode finger 20 can be parallel to the first direction.

[0078] Referring to Figure 3For example, each electrode finger 20 is arranged between the first bus bar 11 and the second bus bar 12; in the first direction, one end of the first electrode finger 201 is connected to the first bus bar 11, and the other end of the first electrode finger 201 is arranged apart from the second bus bar 12; one end of the second electrode finger 202 is connected to the second bus bar 12, and the other end of the second electrode finger 202 is arranged apart from the first bus bar 11. It can be understood that the end of each first electrode finger 201 close to the second bus bar 12 can be flush or not flush, and the end of each second electrode finger 202 close to the first bus bar 11 can be flush or not flush. In the second direction, the widths of the electrode fingers 20 can be the same or different. In the second direction, the widths of the widened portions 21 of the electrode fingers 20 can be the same or different.

[0079] Referring to Figure 3 The intersection region A1 and the gap region B1 located at the two ends of the intersection region A1 in the first direction are formed between the two bus bars 10. It can be understood that the region between the first electrode finger 201 and the second bus bar 12 and the region between the second electrode finger 202 and the first bus bar 11 are both gap regions B1.

[0080] Referring to Figure 3 In some embodiments, the surface acoustic wave device 1000 further comprises an auxiliary structure 400 located in the edge region A12; the electrode finger 20 comprises a widened portion 21 located in the edge region A12. Among them, in the same edge region A12, the projections of the widened portion 21 and the auxiliary structure 400 in the top view direction are at least partially staggered in the length extension direction of the electrode finger 20, and the acoustic impedance of the region provided with the widened portion 21 is different from the acoustic impedance of the region provided with the auxiliary structure 400.

[0081] The surface acoustic wave device 1000 in the above embodiment, since the projection of the widening portion 21 and the auxiliary structure 400 in the top view direction is arranged at least partially staggered along the length extension direction of the electrode finger 20 at the same edge region A12 of the interdigital transducer 200 of the surface acoustic wave device 1000, and the acoustic impedance of the region provided with the widening portion 21 is different from the acoustic impedance of the region provided with the auxiliary structure 400 in the same edge region A12, by arranging the projection of the widening portion 21 and the auxiliary structure 400 in the top view direction at least partially staggered along the length extension direction of the electrode finger 20 in the same edge region A12, the acoustic impedance of the edge region A12 is adjusted, so that the acoustic impedance of the region provided with the widening portion 21 is different from the acoustic impedance of the region provided with the auxiliary structure 400, so that the surface acoustic wave device 1000 can better suppress both the high-order transverse mode and the low-order transverse mode, thereby effectively suppressing the transverse mode of the surface acoustic wave device 1000, minimizing the adverse effects of the transverse mode on the surface acoustic wave device 1000, and effectively preventing energy leakage. In addition, the surface acoustic wave device 1000 in the embodiment of the application is arranged by staggering the widening portion 21 and the auxiliary structure 400, which is not easily affected by the spacing distance of the adjacent electrode fingers 20 in the second direction during device manufacturing, and can be applied to a higher frequency band. In addition, the embodiment can also reduce the occurrence of quality problems such as difficulty in processing or easy processing of short circuits due to too small spacing distance of adjacent electrode fingers 20, and compared to two additional structures 400 of different thicknesses, the process steps can be reduced and the cost can be reduced. The surface acoustic wave device 1000 in the embodiment of the application has a reasonable structure design, is easy to process, and has good transverse mode suppression effect.

[0082] In some embodiments, the average of the acoustic impedance of the region provided with the widening portion 21 and the acoustic impedance of the region provided with the auxiliary structure 400 in the intersection region A1 is E; E is less than the acoustic impedance of the middle region A11. Illustratively, the projection of the widening portion 21 and the auxiliary structure 400 in the top view direction is arranged at least partially staggered along the length extension direction of the electrode finger 20 in the same edge region A12, so that the acoustic impedance of the region provided with the widening portion 21 is different from the acoustic impedance of the region provided with the auxiliary structure 400 in the same edge region A12; and the average of the acoustic impedance of the two structures E is less than the acoustic impedance of the middle region A11, which can ensure that the surface acoustic wave device 1000 can effectively suppress the high-order transverse mode and the low-order transverse mode, thereby sufficiently suppressing the transverse mode and having good transverse mode suppression effect.

[0083] In some embodiments, the acoustic impedance of the region provided with the auxiliary structure 400 is smaller than the acoustic impedance of the region not provided with the auxiliary structure 400 and the widened portion 21 within the same edge region A12. Exemplarily, the projections of the widened portion 21 and the auxiliary structure 400 in the top-down direction are arranged to be at least partially staggered along the length extension direction of the electrode finger 20 within the same edge region A12, such that the acoustic impedance of the region provided with the widened portion 21 is different from the acoustic impedance of the region provided with the auxiliary structure 400 within the same edge region A12. When the projections of the widened portion 21 and the auxiliary structure 400 corresponding to the same electrode finger 20 are arranged to be spaced apart along the length extension direction of the electrode finger 20 within the same edge region A12, or when there is a region not provided with the widened portion 21 and the auxiliary structure 400 in addition to the region provided with the widened portion 21 or the auxiliary structure 400, the acoustic impedance of the region provided with the auxiliary structure 400 is smaller than the acoustic impedance of the region not provided with the auxiliary structure 400 and the widened portion 21, a larger acoustic impedance difference can be formed in the edge region A12, and a higher resonant frequency of the transverse mode of the surface acoustic wave device can be suppressed, and a filter in a high frequency band can be implemented.

[0084] In some embodiments, the acoustic impedance of the region provided with the auxiliary structure 400 is smaller than the acoustic impedance of the region not provided with the auxiliary structure 400 and the widened portion 21 within the same edge region A12. Exemplarily, the projections of the widened portion 21 and the auxiliary structure 400 in the top-down direction are arranged to be at least partially staggered along the length extension direction of the electrode finger 20 within the same edge region A12, such that the acoustic impedance of the region provided with the widened portion 21 is different from the acoustic impedance of the region provided with the auxiliary structure 400 within the same edge region A12. When the projections of the widened portion 21 and the auxiliary structure 400 corresponding to the same electrode finger 20 are arranged to be spaced apart along the length extension direction of the electrode finger 20 within the same edge region A12, or when there is a region not provided with the widened portion 21 and the auxiliary structure 400 in addition to the region provided with the widened portion 21 or the auxiliary structure 400, the acoustic impedance of the region provided with the auxiliary structure 400 is smaller than the acoustic impedance of the region not provided with the auxiliary structure 400 and the widened portion 21, a larger acoustic impedance difference can be formed in the edge region A12, and a higher resonant frequency of the transverse mode of the surface acoustic wave device can be suppressed, and a filter in a high frequency band can be implemented.

[0085] In some embodiments, the acoustic impedance of the region provided with the auxiliary structure 400 is smaller than the acoustic impedance of the region provided with the widened portion 21. The acoustic impedance of the region provided with the auxiliary structure 400 is lower than the acoustic impedance of the region provided with the widened portion 21, so that a high-low fluctuation acoustic impedance distribution can be formed in the edge region A12, a larger acoustic impedance difference can be achieved, a higher resonant frequency of the transverse mode of the surface acoustic wave device can be suppressed, and a filter in a high frequency band can be implemented.

[0086] In some embodiments, the acoustic impedance of one of the widening 21 and the appendage structure 400 closer to the middle region Al 1 is greater than the acoustic impedance of the other farther from the middle region Al 1, so that a high-low undulating acoustic impedance distribution can be formed in the edge region A12 to better suppress the high-order transverse mode and the low-order transverse mode, and improve the performance of the surface acoustic wave device. For example, referring to Figure 3 In some embodiments, the acoustic impedance of one of the widening 21 and the appendage structure 400 closer to the middle region Al 1 is greater than the acoustic impedance of the other farther from the middle region Al 1, so that a high-low undulating acoustic impedance distribution can be formed in the edge region A12 to better suppress the high-order transverse mode and the low-order transverse mode, and improve the performance of the surface acoustic wave device. For example, referring to Figure 3 In some embodiments, the acoustic impedance of one of the widening 21 and the appendage structure 400 closer to the middle region Al 1 is greater than the acoustic impedance of the other farther from the middle region Al 1, so that a high-low undulating acoustic impedance distribution can be formed in the edge region A12 to better suppress the high-order transverse mode and the low-order transverse mode, and improve the performance of the surface acoustic wave device. For example, referring to

[0087] In some embodiments, the acoustic impedance of one of the widening 21 and the appendage structure 400 closer to the middle region Al 1 is greater than the acoustic impedance of the other farther from the middle region Al 1, so that a high-low undulating acoustic impedance distribution can be formed in the edge region A12 to better suppress the high-order transverse mode and the low-order transverse mode, and improve the performance of the surface acoustic wave device. For example, referring to Figure 7 In some embodiments, the acoustic impedance of one of the widening 21 and the appendage structure 400 closer to the middle region Al 1 is greater than the acoustic impedance of the other farther from the middle region Al 1, so that a high-low undulating acoustic impedance distribution can be formed in the edge region A12 to better suppress the high-order transverse mode and the low-order transverse mode, and improve the performance of the surface acoustic wave device. For example, referring to

[0088] Exemplarily, in the arrangement direction of the two bus bars 10, the projection of the auxiliary structure 400 in the top view direction can cover the gap region B1. In some embodiments, in the top view direction, the electrode fingers 20 can also be appropriately exposed from the auxiliary structure 400 in the arrangement direction of the two bus bars 10. Exemplarily, the length of the exposed part is much smaller than the length of the part covered by the auxiliary structure 400. Exemplarily, in the arrangement direction of the two bus bars 10, the projection of the auxiliary structure 400 in the top view direction is flush with or closer to the middle region A11 than the end of the electrode finger 20 away from the connected bus bar 10.

[0089] It can be understood that the length and / or width of the widened part 21 can be adjusted to adjust the acoustic impedance of the region where the widened part 21 is located, in cooperation with the auxiliary structure 400, to achieve good high-order transverse mode suppression effect and good low-order transverse mode suppression effect. Similarly, the length of the auxiliary structure 400 in the arrangement direction of the two bus bars 10 and the thickness of the auxiliary structure 400 in the top view direction can be designed in at least one of the ways to cooperate with the widened part 21 to achieve good high-order transverse mode suppression effect and good low-order transverse mode suppression effect. Please refer to Figure 3 , exemplarily, in the arrangement direction of the bus bars 10, the middle region A11 is provided with one edge region A12 on each side, and the widened part 21 at one of the edge regions A12 and the widened part 21 at the other edge region A12 can be arranged in axial symmetry or in non-axial symmetry; and the auxiliary structure 400 at one of the edge regions A12 and the auxiliary structure 400 at the other edge region A12 can be arranged in axial symmetry or in non-axial symmetry. For example, the size of at least one of the widened part 21 and the auxiliary structure 400 on each side of the same electrode finger 20 can be different, or the position of at least one of the widened part 21 and the auxiliary structure 400 on each side of the same electrode finger 20 can be different. Exemplarily, the shape of the cross region A1 (i.e. the aperture of the interdigital transducer 200) can be any suitable shape such as a rectangle or a wave shape. The shape of the cross region A1 can be non-rectangular (i.e. other than a rectangle) by at least one of the following ways: adjusting at least one of the position and shape of the widened part 21 and / or the auxiliary structure 400 at the edge region A12; designing the middle region A11 to be other than a rectangle.

[0090] Please refer to Figure 4 In some embodiments, the length of the widened part 21 in the arrangement direction of the two bus bars 10 is L2, and 0 < L2 < 2.8λ, where λ is the period of the electrode finger 20. For example, L2 is 0.1λ, 0.5λ, 1λ, 1.5λ, 2λ, 2.7λ or any other suitable value within the range of 0-2.8λ. L2 is within the range, which is easy and convenient to process, the yield of the processed product is high, and the high-order transverse mode and the low-order transverse mode can be effectively suppressed.

[0091] In some embodiments, the thickness of the widened portion 21 is equal to the thickness of the electrode finger 20 located in the middle region A11, so that the widened portion 21 and the electrode finger 20 can be processed in the same process, and the processing of the surface acoustic wave device 1000 is simple, easy and efficient. In other embodiments, the widened portion 21 can also be processed in a different process from the electrode finger 20 located in the middle region A11. The thickness of the widened portion 21 can also be different from the thickness of the electrode finger 20 located in the middle region A11.

[0092] Referring to Figure 4 In some embodiments, the width of the auxiliary structure 400 along the arrangement direction of the electrode finger 20 is W1, the width of the electrode finger 20 along the arrangement direction of the electrode finger 20 is W3, and W1≥W3 / 2, so that the high-order transverse mode and the low-order transverse mode can be effectively suppressed, and the processing is easy and convenient.

[0093] For example, the length of the widened portion 21 along the arrangement direction of the two bus bars 10 is L2, 0<L2<2.8λ, and λ is the period of the electrode finger 20; the width of the auxiliary structure 400 along the arrangement direction of the electrode finger 20 is W1, the width of the electrode finger 20 along the arrangement direction of the electrode finger 20 is W3, and W1≥W3 / 2, so that the high-order transverse mode and the low-order transverse mode can be more effectively suppressed; and the processing of the surface acoustic wave device 1000 is easier and more convenient.

[0094] Referring to Figure 4 In some embodiments, the length of the auxiliary structure 400 along the arrangement direction of the two bus bars 10 is L1, 0.01λ<L1<2.6λ, and λ is the period of the electrode finger 20. For example, L1 is 0.02λ, 0.5λ, 1λ, 1.5λ, 2λ, 2.5λ or other arbitrary suitable values within the range of 0.01λ-2.6λ. L1 is within the range, the processing is easy, the qualified rate of the processed product is high, and the high-order transverse mode and the low-order transverse mode can be effectively suppressed.

[0095] In some embodiments, the thickness of the auxiliary structure 400 is H1, where 0.002λ < H1 < 2λ, and λ is the period of the electrode fingers 20. For example, H1 is 0.003λ, 0.01λ, 0.5λ, 1λ, 1.5λ, 1.9λ, or any other suitable value within 0.002λ - 2λ. When H1 is within this range, processing is easy and convenient, the qualified rate of the processed products is high, and high-order lateral modes and low-order lateral modes can be effectively suppressed. Here, the thickness of the auxiliary structure 400 refers to the thickness of the auxiliary structure 400 in the top view direction. Exemplarily, 0.01λ < L1 < 2.6λ and 0.002λ < H1 < 2λ, so that the processing of the surface acoustic wave device 1000 is easier and more convenient, and high-order lateral modes and low-order lateral modes can be fully and effectively suppressed.

[0096] Exemplarily, the length of the auxiliary structure 400 in the arrangement direction of the two bus bars 10 is L1, where 0.01λ < L1 < 2.6λ; the thickness of the auxiliary structure 400 is H1, where 0.002λ < H1 < 2λ, and λ is the period of the electrode fingers 20. In this way, high-order lateral modes and low-order lateral modes can be effectively suppressed as much as possible, and further, the processing of the surface acoustic wave device 1000 is made easier and more convenient.

[0097] Please refer to Figure 4 , in some embodiments, within the same edge region A12, the width of the widening portion 21 in the arrangement direction of the electrode fingers 20 is W2, the width of the electrode fingers 20 in the arrangement direction of the electrode fingers 20 is W3, and the center-to-center distance between two adjacent electrode fingers 20 is P3, where W3 ≤ W2 < (2P3 - W3). In this way, high-order lateral modes and low-order lateral modes can be effectively suppressed, and processing is easy and convenient.

[0098] Exemplarily, the length of the widening portion 21 in the arrangement direction of the two bus bars 10 is L2, where 0 < L2 < 2.8λ, and λ is the period of the electrode fingers 20; the width of the auxiliary structure 400 in the arrangement direction of the electrode fingers 20 is W1, the width of the electrode fingers 20 in the arrangement direction of the electrode fingers 20 is W3, and W1 ≥ W3 / 2; the length of the auxiliary structure 400 in the arrangement direction of the two bus bars 10 is L1, where 0.01λ < L1 < 2.6λ; the thickness of the auxiliary structure 400 is H1, where 0.002λ < H1 < 2λ. In this way, high-order lateral modes and low-order lateral modes can be effectively suppressed to the greatest extent, and further, the processing of the surface acoustic wave device 1000 is made easier and more convenient.

[0099] Please refer to Figure 3In some embodiments, the projection of the widened portion 21 and the auxiliary structure 400 corresponding to the same electrode finger 20 in the top view direction abut along the length extension direction of the electrode finger 20 within the same edge region A12. That is, the projection of the widened portion 21 and the auxiliary structure 400 corresponding to the same electrode finger 20 in the top view direction are arranged adjacent to each other in the first direction and the projections of the two are in contact in the first direction within the same edge region A12. In this way, the surface acoustic wave device 1000 can better suppress the high-order transverse mode and the low-order transverse mode, thereby better suppressing the transverse mode, and can save material and reduce cost. Understandably, within a reasonable processing error range, the projection of the widened portion 21 and the auxiliary structure 400 corresponding to the same electrode finger 20 in the top view direction abut along the length extension direction of the electrode finger 20 within the same edge region A12.

[0100] Please refer to Figure 5 In other embodiments, the projection of the widened portion 21 and the auxiliary structure 400 corresponding to the same electrode finger 20 in the top view direction are arranged spaced apart along the length extension direction of the electrode finger 20 within the same edge region A12, thereby allowing a certain process tolerance, strong operability, low process cost, and improved product yield, and better suppressing the abutting transverse mode and the high-order transverse mode.

[0101] Please refer to Figure 6 In yet other embodiments, the projection of the widened portion 21 and the auxiliary structure 400 corresponding to the same electrode finger 20 in the top view direction partially overlaps along the length extension direction of the electrode finger 20 within the same edge region A12, thereby allowing a certain process tolerance, strong operability, low process cost, and improved product yield, and better suppressing the abutting transverse mode and the high-order transverse mode. Illustratively, the acoustic impedance of the region where the projection of the auxiliary structure 400 and the widened portion 21 in the top view direction overlaps within the same edge region A12 is less than the acoustic impedance of the rest of the region, and forming such a distribution of acoustic impedance can better suppress the high-order transverse mode and the low-order transverse mode, thereby suppressing the transverse mode first during the leakage of the acoustic wave from the intersection region A1 to the gap region B1. Illustratively, please refer to Figure 6 The length of the widened portion 21 and the auxiliary structure 400 that are staggered with each other is much greater than the length of the overlapping portion of the two, and the length of the widened portion 21 and the auxiliary structure 400 that are staggered with each other refers to the length of the widened portion 21 and the auxiliary structure 400 along the length extension direction of the electrode finger 20.

[0102] Please refer to Figure 5In some embodiments, the projection of the widened portion 21 and the auxiliary structure 400 corresponding to the same electrode finger 20 in the same edge region A12 in the top view direction is spaced apart by a preset distance L3 along the length extension direction of the electrode finger 20, and L3 < 2.6λ, where λ is the period of the electrode finger 20. For example, refer to FIG. 2B. Figure 5 In the same edge region A12, the projection of the widened portion 21 and the auxiliary structure 400 corresponding to the same electrode finger 20 in the top view direction is spaced apart along the length extension direction of the electrode finger 20, and the spacing distance between them is L3, L3 < 2.6λ, so that the size of the surface acoustic wave device 1000 along the length extension direction of the electrode finger 20 is as small as possible under the premise of better suppressing high-order transverse modes and low-order transverse modes, which is conducive to product miniaturization and cost reduction. For example, the size of the widened portion 21 along the length extension direction of the electrode finger 20 is greater than L3, and the size of the auxiliary structure 400 along the length extension direction of the electrode finger 20 is greater than L3.

[0103] For example, refer to FIG. 2B. Figure 6 In some embodiments, the projection of the widened portion 21 and the auxiliary structure 400 corresponding to the same electrode finger 20 in the same edge region A12 in the top view direction is spaced apart along the length extension direction of the electrode finger 20, and the spacing distance between them is L3, L3 < 2.6λ, where λ is the period of the electrode finger 20. For example, refer to FIG. 2B. Figure 6 In the same edge region A12, the projection of the widened portion 21 and the auxiliary structure 400 corresponding to the same electrode finger 20 in the top view direction is partially overlapped along the length extension direction of the electrode finger 20, and the overlap distance between them is L4, L4 < 2.6λ, so that the size of the widened portion 21 and the auxiliary structure 400 along the length extension direction of the electrode finger 20 is reduced under the premise of better suppressing high-order transverse modes and low-order transverse modes, which is conducive to product miniaturization and cost reduction. For example, in the same edge region A12, the widened portion 21 includes a first staggered region, the projection of the first staggered region and the auxiliary structure 400 corresponding to the same electrode finger 20 in the top view direction is adjacent and staggered, and the size of the first staggered region along the length extension direction of the electrode finger 20 is greater than L4; the auxiliary structure 400 includes a second staggered region, the projection of the second staggered region and the widened portion 21 corresponding to the same electrode finger 20 in the top view direction is adjacent and staggered, and the size of the second staggered region along the length extension direction of the electrode finger 20 is greater than L4.

[0104] For example, refer to FIG. 2B. Figure 3In some embodiments, within the same edge region A12, the widened portion 21 is closer to the middle region Al 1 than at least part of the auxiliary structure 400, so as to balance the ease of processing, good high-order transverse mode suppression effect and good low-order mode suppression effect. For example, within the same edge region A12, the projection of the widened portion 21 and the auxiliary structure 400 corresponding to the same electrode finger 20 in the top view direction abuts along the length extension direction of the electrode finger 20, and the widened portion 21 is closer to the middle region Al 1 than the auxiliary structure 400. Exemplarily, within the same edge region A12, the widened portion 21 is closer to the middle region Al 1 than the auxiliary structure 400, so that in the structure in which the acoustic impedance of the region provided with the widened portion 21 is greater than the acoustic impedance of the region provided with the auxiliary structure 400, the acoustic impedance difference of the two parts can be adjusted in a larger range, so as to make the width of the widened portion 21 (located inside the edge region A12) smaller on the basis of improving the high-order transverse mode and abutting transverse mode suppression effect, so that the influence of the widened portion 21 on the resonant frequency of the device is smaller, so that the spacing between the electrode fingers 20 of the device can be smaller, so that the device can be applied to a higher frequency band filter. Therefore, the high-order transverse mode and the low-order transverse mode can have better suppression effect at a higher frequency band. It can be understood that the widened portion 21 is closer to the middle region Al 1 than at least part of the auxiliary structure 400, including at least one of the following cases: case a), within the same edge region A12, the projection of the widened portion 21 and the auxiliary structure 400 corresponding to the same electrode finger 20 in the top view direction partially overlaps along the length extension direction of the electrode finger 20, and the widened portion 21 is closer to the middle region Al 1 than the part of the auxiliary structure 400 that does not overlap with the widened portion 21. Case b), within the same edge region A12, the projection of the widened portion 21 and the auxiliary structure 400 corresponding to the same electrode finger 20 in the top view direction is abutted or spaced along the length extension direction of the electrode finger 20, and the widened portion 21 is closer to the middle region Al 1 than the auxiliary structure 400.

[0105] Exemplarily, in the same edge region A12, the projection of the widened portion 21 and the auxiliary structure 400 corresponding to the same electrode finger 20 in the top view direction is adjacent along the length extension direction of the electrode finger 20, the widened portion 21 is closer to the middle region A11 than the auxiliary structure 400, the length of the auxiliary structure 400 along the arrangement direction of the two bus bars 10 is L1, 0.01λ<L1<2.6λ; the thickness of the auxiliary structure 400 is H1, 0.002λ<H1<2λ; the length of the widened portion 21 along the arrangement direction of the two bus bars 10 is L2, 0<L2<2.8λ; the width of the widened portion 21 along the arrangement direction of each electrode finger 20 is W2, the width of the electrode finger 20 along the arrangement direction of each electrode finger 20 is W3, the center distance between adjacent two electrode fingers 20 is P3, W3≤W2<(2P3 / 2-W3). In this way, the processing of the surface acoustic wave device 1000 can be facilitated, and the high-order transverse mode and the low-order transverse mode can be suppressed as much as possible.

[0106] Please refer to Figure 7 In some embodiments, in the same edge region A12, the widened portion 21 is farther away from the middle region A11 than at least part of the auxiliary structure 400. Exemplarily, in the same edge region A12, the widened portion 21 is adjacent to the auxiliary structure 400, and the widened portion 21 is farther away from the middle region A11 than the auxiliary structure 400.

[0107] Please refer to Figure 8In some embodiments, the auxiliary structure 400 comprises a plurality of auxiliary blocks 401, which are arranged in sequence and spaced apart in the arrangement direction of the electrode fingers 20, and the projection of each electrode finger 20 and the corresponding auxiliary block 401 in the top view direction at least partially overlaps. That is, the auxiliary structure 400 is discontinuously arranged along the arrangement direction of the electrode fingers 20, so that the material used by the auxiliary structure 400 is less on the basis of ensuring better high-order transverse mode suppression effect and low-order transverse mode suppression effect, the weight of the auxiliary structure 400 can be reduced to reduce the weight of the surface acoustic wave device 1000, which is conducive to realizing the light weight of the product and reducing the cost. It can be understood that the overlapping area of the projection of each electrode finger 20 and the corresponding auxiliary block 401 in the top view direction can be the same or different. The size of the two in the arrangement direction of the electrode fingers 20 can be the same or different. For the same auxiliary structure 400, the length of each auxiliary block 401 included along the arrangement direction of the two bus bars 10 can be the same or different; the width of each auxiliary block 401 included along the arrangement direction of the electrode fingers 20 can be the same or different; the thickness of each auxiliary block 401 included can be the same or different. Exemplarily, the length, width and thickness of each auxiliary block 401 facilitate manufacturing in the same process, reducing process cost. In some embodiments, each auxiliary block 401 overlaps with the corresponding electrode finger 20 in the arrangement direction of the electrode fingers 20.

[0108] Referring to Figure 3 In some embodiments, the projection of the auxiliary structure 400 and the electrode fingers 20 in the top view direction overlaps in the arrangement direction of the electrode fingers 20 and overlaps with the projection of the gap between any two adjacent electrode fingers 20 in the top view direction. That is, the auxiliary structure 400 is continuously and uninterruptedly arranged along the arrangement direction of the electrode fingers 20, so that the processing of the auxiliary structure 400 is simple and convenient on the basis of ensuring better high-order transverse mode suppression effect and low-order transverse mode suppression effect.

[0109] Referring to Figure 9 In some embodiments, the auxiliary structure 400 is arranged on the side of the interdigital transducer 200 facing the piezoelectric substrate 100, so that the auxiliary structure 400 can be manufactured in the same process, reducing the process steps and reducing the cost. Referring to Figure 10In some embodiments, the auxiliary structure 400 is arranged on the side of the interdigital transducer 200 away from the piezoelectric substrate 100, so that the auxiliary structure 400 can be completed in the same process, thereby reducing the process steps and lowering the cost. In addition, the auxiliary structure 400 is arranged on the side of the interdigital transducer 200 away from the piezoelectric substrate 100, and the auxiliary structure 400 and the interdigital transducer 200 are easy and convenient to process, and the surface acoustic wave device 1000 is easy and convenient to process. In yet some embodiments, one part of the auxiliary structure 400 is arranged on the side of the interdigital transducer 200 facing the piezoelectric substrate 100, and another part of the auxiliary structure 400 is arranged on the side of the interdigital transducer 200 away from the piezoelectric substrate 100.

[0110] Referring to Figure 10 In some embodiments, the auxiliary structure 400 is arranged to be attached to the electrode finger 20 in the top view. Referring to Figure 11 In some embodiments, the auxiliary structure 400 is arranged to be spaced apart from the electrode finger 20 in the top view, which is conducive to taking into account the ease of processing and the reliability of the product.

[0111] The shape of the auxiliary structure 400, the auxiliary block 401 and / or the widened portion 21 can be designed according to actual needs, which is not limited herein. For example, the auxiliary structure 400 is shown as a strip in Figure 4 , or is shown as a shape in Figure 12 (a) or 12(b), or any other suitable regular shape or irregular shape, etc. For example, the shape of the widened portion 21 is shown as a square in Figure 4 , or is shown as any one of the shapes in Figure 12 (c)-12(f), or any other suitable regular shape or irregular shape, etc.

[0112] Exemplarily, the widened portion 21 can be made in the same process as the electrode finger 20, and the auxiliary structure 400 is made in another process. The auxiliary structure 400 can be made in the same process, which can reduce the manufacturing process of the surface acoustic wave device 1000 compared to the scheme of realizing the acoustic impedance difference by making the auxiliary structure 400 through two different processes.

[0113] The auxiliary structure 400 can be a single metal or a composite or alloy of different metals. Exemplarily, the material of the auxiliary structure 400 can be one of molybdenum, tungsten, ruthenium, gold, magnesium, aluminum, copper, chromium, titanium, osmium, iridium, or a composite or alloy thereof, etc. Of course, the material of the auxiliary structure 400 can also be a dielectric, such as tantalum oxide, etc. In some embodiments, the auxiliary structure 400 is a conductive structure or a non-conductive structure. The conductive structure can include a structure made of a conductive metal. The material of the non-conductive structure can include silicon dioxide or any other suitable material, etc.

[0114] In some embodiments, the auxiliary structure 400 is a conductive structure, and the auxiliary structure 400 comprises auxiliary blocks 401, which are arranged in sequence and spaced apart in the arrangement direction of the electrode fingers 20; each electrode finger 20 is arranged in contact with one auxiliary block 401 in the top view; and the surface acoustic wave device 1000 further comprises a dielectric layer 500 (see Figure 11 ). The surface acoustic wave device 1000 with such a structure has a reasonable design, is easy, convenient and simple to process, and has a good transverse mode suppression effect. For example, the auxiliary structure 400 is a conductive structure; each electrode finger 20 is arranged in contact with one auxiliary block 401 in the top view, and the electrode finger 20 and the auxiliary block 401 can be manufactured in the same process, such as the electrode finger 20 and the auxiliary block 401 are both manufactured by plating process, and the electrode finger 20 and the auxiliary block 401 do not need to be manufactured by two different processes, so that the surface acoustic wave device 1000 is easy, convenient and simple to process.

[0115] In some embodiments, the auxiliary structure 400 is a non-conductive structure; and the auxiliary structure 400 is arranged in contact with the interdigital transducer 200 in the top view. For example, the auxiliary structure 400 overlaps the projection of each electrode finger 20 in the top view, and overlaps the projection of the gap between any two adjacent electrode fingers 20 in the top view, that is, the auxiliary structure 400 is a continuous and uninterrupted strip structure, and the auxiliary structure 400 is arranged in contact with the interdigital transducer 200 in the top view, so that the auxiliary structure 400 is a non-conductive structure.

[0116] In other embodiments, the auxiliary structure 400 can be a conductive structure or a non-conductive structure. For example, a dielectric layer 500 is arranged between the auxiliary structure 400 and the interdigital transducer 200 in the top view; and the auxiliary structure 400 is a non-conductive structure. The surface acoustic wave device 1000 with such a structure is easy, convenient and simple to process, and has a good high-order transverse mode and low-order transverse mode suppression effect. For example, a dielectric layer 500 is arranged between the auxiliary structure 400 and the interdigital transducer 200 in the top view, and the auxiliary structure 400 and the interdigital transducer 200 are manufactured separately, such as the auxiliary structure 400 is manufactured by etching process or stripping process, and the interdigital transducer 200 is manufactured by plating process; the auxiliary structure 400 is a non-conductive structure, which is convenient for manufacturing the auxiliary structure 400 and / or the interdigital transducer 200, and thus the surface acoustic wave device 1000 is easy, convenient and simple to process.

[0117] Please refer to Figure 11In some embodiments, the surface acoustic wave device 1000 further comprises a dielectric layer 500, the dielectric layer 500 covering the interdigital transducer 200, the dielectric layer 500 being arranged on the side of the electrode fingers 20 away from the piezoelectric substrate 100. The dielectric layer 500 can protect the interdigital transducer 200 and / or the auxiliary structure 400, etc. For example, the dielectric layer 500 covers the interdigital transducer 200 and the auxiliary structure 400. The dielectric layer 500 can completely cover the interdigital transducer 200, or can not completely cover the interdigital transducer 200, for example, only covering the area where the electrode fingers 20 are located, and the bus bar 10 is not covered.

[0118] In some embodiments, the dielectric layer 500 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 silicon oxide, silicon nitride, silicon oxynitride, etc. The material of the temperature compensation layer is usually one of the above materials, i.e., 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, which can be a mixture of any of the above materials, or a mixture of one or more of the above materials and other materials. In other embodiments, the dielectric layer 500 can also include at least one of the following: a frequency adjustment layer, a passivation layer. The frequency adjustment layer is used to adjust the frequency of the surface acoustic wave device 1000. The material of the frequency adjustment layer can be at least one of silicon dioxide, silicon nitride, aluminum nitride, aluminum oxide, etc. The passivation layer is used to protect the interdigital transducer 200 and / or the auxiliary structure 400, etc. The material of the passivation layer can be at least one of silicon dioxide, silicon nitride, aluminum nitride, aluminum oxide, etc.

[0119] For example, Figure 11 In some embodiments, the auxiliary structure 400 is arranged on the side of the dielectric layer 500 away from the electrode fingers 20. For example, in the top view, at least part of the dielectric layer 500 is arranged between the auxiliary structure 400 and the electrode fingers 20, i.e., the auxiliary structure 400 and the electrode fingers 20 are arranged apart in the top view, and the dielectric layer 500 is filled between the auxiliary structure 400 and the electrode fingers 20. Figure 10 In some embodiments, the dielectric layer 500 is arranged on the side of the auxiliary structure 400 away from the electrode fingers 20, i.e., in the top view, the auxiliary structure 400 is arranged between the dielectric layer 500 and the electrode fingers 20.

[0120] For example, Figure 2 In some embodiments, the piezoelectric substrate 100 comprises a substrate 101 and a piezoelectric film 102 arranged in layers, and the interdigital transducer 200 is arranged 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 it can be applied to higher frequency bands of 5G and above. For example, the material of the substrate 101 can be silicon.

[0121] Referring to Figure 13 In some embodiments, the interdigital transducer 200 further comprises a dummy finger 30, one end of the dummy finger 30 being connected to one of the bus bars 10, and the other end of the dummy finger 30 being spaced apart from the tip of the electrode finger 20 connected to the other bus bar 10. By arranging the dummy finger 30, the transverse mode interference of the surface acoustic wave device 1000 can be suppressed, the energy leakage can be reduced, and thus the Q value of the surface acoustic wave device 1000 can be improved.

[0122] Referring to Figure 13 For example, the number of the dummy fingers 30 includes a plurality of dummy fingers 30, the plurality of dummy fingers 30 including a first dummy finger 31 and a second dummy finger 32, one end of the first dummy finger 31 being connected to the first bus bar 11, and the other end of the first dummy finger 31 being spaced apart from the second electrode finger 202 in the arrangement direction of the two bus bars 10; one end of the second dummy finger 32 being connected to the second bus bar 12, and the other end of the second dummy finger 32 being spaced apart from the first electrode finger 201 in the arrangement direction of the two bus bars 10. The number of the first dummy fingers 31 and the number of the second dummy fingers 32 can be designed according to actual needs, such as one or more. For example, the number of the first dummy fingers 31 is a plurality, and the end of each first dummy finger 31 away from the first bus bar 11 can be flush or not flush, and one first dummy finger 31 can be arranged between adjacent two first electrode fingers 201. The number of the second dummy fingers 32 is a plurality, and the end of each second dummy finger 32 away from the second bus bar 12 can be flush or not flush, and one second dummy finger 32 can be arranged between adjacent two second electrode fingers 202.

[0123] It can be understood that when the surface acoustic wave device 1000 is provided with the first dummy finger 31 and the second dummy finger 32, the gap region B1 is actually a region located between the first dummy finger 31 and the second electrode finger 202 in the arrangement direction of the two bus bars 10; or a region located between the second dummy finger 32 and the first electrode finger 201.

[0124] As Figure 14- Figure 16 shown, the surface acoustic wave device 1000 of the embodiment of the present application is compared with the surface acoustic wave device 1000 of the conventional structure.

[0125] Figure 14 The admittance curve of the surface acoustic wave device 1000 of Comparative Example 1 is shown in FIG. 6, wherein the surface acoustic wave device 1000 of Comparative Example 1 is not provided with the widened portion 21 and the auxiliary structure 400. Figure 14 In FIG. 6, the abscissa is frequency, unit: GHz; and the ordinate is admittance, unit: dB. It can be seen from FIG. 6 that the surface acoustic wave device 1000 has a large transverse mode between the resonance point and the anti-resonance point. Figure 14

[0126] Figure 15 ​A graph of the admittance curve of the surface acoustic wave device 1000 of Comparative Example 2, in which the surface acoustic wave device 1000 of Comparative Example 2 is provided with only one of the widened portion 21 and the auxiliary structure 400. Figure 15 In the graph, the horizontal axis represents frequency in GHz, and the vertical axis represents admittance in dB. Figure 15 The surface acoustic wave device 1000 of Comparative Example 2 can suppress the lateral mode by adjusting the structural features of the widened portion 21 or the auxiliary structure 400, but Figure 15 In Comparative Example 2, the low-order lateral mode can be suppressed, but the high-order lateral mode is not suppressed well.

[0127] Figure 16 A graph of the admittance curve of the surface acoustic wave device 1000 of an embodiment of the present application. Figure 16 In the graph, the horizontal axis represents frequency in GHz, and the vertical axis represents admittance in dB. Figure 16 The surface acoustic wave device 1000 of the embodiment of the present application can suppress the lateral mode well. Figure 14 , Figure 15 As can be seen from the comparison, the embodiment of the present application can suppress the high-order lateral mode and the low-order lateral mode well by providing the widened portion 21 and the auxiliary structure 400 at the same time, the widened portion 21 and the auxiliary structure 400 being at least partially staggered and having different acoustic impedances.

[0128] Figure 17 A comparison graph of the real part of the admittance curve of the surface acoustic wave device 1000 of an embodiment of the present application and the surface acoustic wave device 1000 of a comparative example. In the graph, the dashed line represents the real part of the admittance curve of the surface acoustic wave device 1000 of the comparative example, and the solid line represents the real part of the admittance curve of the surface acoustic wave device 1000 of the embodiment of the present application. The comparative example is a graph of the real part of the admittance curve in which only one acoustic impedance is provided, and the lateral mode is suppressed well by adjusting the acoustic impedance. In the graph, Figure 17 In the graph, the horizontal axis represents frequency in GHz, and the vertical axis represents the real part of the admittance in dB. Figure 17 As can be seen from the comparison between the solid line and the dashed line in the graph, the high-order lateral mode and the low-order lateral mode of the surface acoustic wave device 1000 of the embodiment of the present application are suppressed well.

[0129] The embodiment of the present application also provides a surface acoustic wave device 1000, comprising a piezoelectric substrate 100, an interdigital transducer 200, an auxiliary structure 400 and a dielectric layer 500, the interdigital transducer 200 is arranged on the piezoelectric substrate 100. In the arrangement direction of the two bus bars 10 of the interdigital transducer 200, the two bus bars 10 have a crossing area A1 between them, the crossing area A1 comprises a middle area A11 and edge areas A12 located at both ends of the middle area A11; wherein, in the arrangement direction of each electrode finger 20 of the interdigital transducer 200, the crossing area A1 is the area where each electrode finger 20 overlaps with each other. The electrode finger 20 comprises a widened part 21 located in the edge area A12; at least one of the two edge areas A12 is provided with the widened part 21 and the auxiliary structure 400. Wherein, in the same edge area A12, the projection of the widened part 21 and the auxiliary structure 400 in the top view direction is at least partially staggered in the length extension direction of the electrode finger 20; the auxiliary structure 400 is a conductive structure, the auxiliary structure 400 comprises a plurality of auxiliary blocks 401, in the arrangement direction of each electrode finger 20, each auxiliary block 401 is arranged in sequence and is spaced apart; in the top view direction, each electrode finger 20 is arranged in close contact with an auxiliary block 401. The dielectric layer 500 is arranged on the piezoelectric substrate 100 and covers the interdigital transducer 200 and the auxiliary structure 400.

[0130] The surface acoustic wave device 1000 of the above embodiment, because the projection of the widened part 21 and the auxiliary structure 400 in the top view direction is at least partially staggered in the length extension direction of the electrode finger 20 at the same edge area A12 of the interdigital transducer 200 of the surface acoustic wave device 1000, the acoustic impedance of the edge area A12 is adjusted, so that the acoustic impedance of the area provided with the widened part 21 is different from the acoustic impedance of the area provided with the auxiliary structure 400, thereby making the surface acoustic wave device 1000 not only able to better suppress high-order transverse modes, but also able to better suppress low-order transverse modes, so as to effectively suppress the transverse modes of the surface acoustic wave device 1000, as far as possible to reduce the adverse effects of the transverse modes on the surface acoustic wave device 1000, and effectively prevent energy leakage. In addition, the surface acoustic wave device 1000 of the embodiment of the present application staggeredly arranges the widened part 21 and the auxiliary structure 400, so that the surface acoustic wave device 1000 is not easily affected by the spacing distance of the adjacent electrode fingers 20 in the second direction during device manufacturing, and can be applied to a higher frequency band. In addition, the embodiment can also reduce the occurrence of quality problems such as difficult to process or easy to process short circuit due to too small spacing distance of adjacent electrode fingers 20, and compared with two additional structures 400 of different thicknesses, the process steps can be reduced and the cost can be reduced. In addition, the scheme of realizing the acoustic impedance difference of the two areas by the two additional structures 40 of different thicknesses needs multiple processing of the additional structures 400 of different thicknesses; compared with the scheme of realizing the acoustic impedance difference of the two areas by the two additional structures 40 of different thicknesses, the surface acoustic wave device 1000 of the embodiment can reduce the processing technology and reduce the process cost.

[0131] In addition, since the surface acoustic wave device 1000 comprises the auxiliary structure 400 and the medium layer 500, the auxiliary structure 400 is a conductive structure, the auxiliary structure 400 comprises a plurality of auxiliary blocks 401, the auxiliary blocks 401 are sequentially and spacedly arranged in the arrangement direction of the electrode fingers 20; each electrode finger 20 is arranged in close contact with an auxiliary block 401 in the top view; the medium layer 500 is arranged on the piezoelectric substrate 100 and covers the interdigital transducer 200 and the auxiliary structure 400, so that the surface acoustic wave device 1000 is easy, convenient and simple to process. The surface acoustic wave device 1000 of the embodiment of the application has a reasonable structure design, is easy to process, and has a good transverse mode suppression effect.

[0132] Exemplarily, one of the two edge regions A12 is provided with the widened portion 21 and the auxiliary structure 400. Exemplarily, both of the two edge regions A12 are simultaneously provided with the widened portion 21 and the auxiliary structure 400.

[0133] Exemplarily, the piezoelectric substrate 100 comprises the piezoelectric substrate 100 of any one of the above embodiments. The interdigital transducer 200 comprises the interdigital transducer 200 of any one of the embodiments of the application. The auxiliary structure 400 comprises the auxiliary structure 400 of any one of the above embodiments. The medium layer 500 comprises the medium layer 500 of any one of the above embodiments.

[0134] The embodiment of the application also provides a surface acoustic wave device 1000, comprising a piezoelectric substrate 100, an interdigital transducer 200 and an auxiliary structure 400; the interdigital transducer 200 is arranged on the piezoelectric substrate 100; in the arrangement direction of the two bus bars 10 of the interdigital transducer 200, the two bus bars 10 have a crossing region A1, the crossing region A1 comprises a middle region A11 and edge regions A12 located at both ends of the middle region A11; wherein, in the arrangement direction of the electrode fingers 20 of the interdigital transducer 200, the crossing region A1 is a region in which the electrode fingers 20 overlap each other. The electrode fingers 20 comprise a widened portion 21 located in the edge region A12, at least one of the two edge regions A12 is provided with the widened portion 21 and the auxiliary structure 400. Wherein, in the same edge region A12, the projection of the widened portion 21 and the auxiliary structure 400 in the top view is at least partially staggered in the length extension direction of the electrode fingers 20; the auxiliary structure 400 is a non-conductive structure; in the top view, the auxiliary structure 400 and the interdigital transducer 200 are provided with the medium layer 500 therebetween.

[0135] The surface acoustic wave device 1000 of the above embodiment can effectively suppress the transverse mode of the surface acoustic wave device 1000, reduce the adverse effects of the transverse mode on the surface acoustic wave device 1000 as much as possible, and effectively prevent energy leakage. In addition, the surface acoustic wave device 1000 of the embodiment of the present application is arranged by staggering the widening portion 21 and the auxiliary structure 400, and is not easily affected by the spacing distance of the adjacent electrode fingers 20 along the second direction during device manufacturing, and can be applied to a higher frequency band. In addition, the embodiment can also reduce the occurrence of quality problems such as difficulty in processing or easy processing of short circuits due to too small spacing distance of the adjacent electrode fingers 20, and compared with two auxiliary structures 400 of different thicknesses, the process steps can be reduced and the cost can be reduced. In addition, the scheme of realizing the acoustic impedance difference of the two regions by the two auxiliary structures 400 of different thicknesses needs multiple processing of the auxiliary structure 400 of different thicknesses; compared with the scheme of realizing the acoustic impedance difference of the two regions by the two auxiliary structures 400 of different thicknesses, the surface acoustic wave device 1000 of the embodiment can reduce the processing technology and reduce the process cost.

[0136] In addition, since the auxiliary structure 400 is a non-conductive structure, a dielectric layer 500 is arranged between the auxiliary structure 400 and the interdigital transducer 200 in the top view direction, so that the surface acoustic wave device 1000 is easy, convenient and simple to process. The surface acoustic wave device 1000 of the embodiment of the present application has a reasonable structure design, is easy to process, and has a good transverse mode suppression effect.

[0137] Exemplarily, one of the two edge regions A12 is provided with the widening portion 21 and the auxiliary structure 400. Exemplarily, both of the two edge regions A12 are simultaneously provided with the widening portion 21 and the auxiliary structure 400.

[0138] Exemplarily, the piezoelectric substrate 100 includes the piezoelectric substrate 100 of any one of the above embodiments. The interdigital transducer 200 includes the interdigital transducer 200 of any one of the embodiments of the present application. The auxiliary structure 400 includes the auxiliary structure 400 of any one of the above embodiments. The dielectric layer 500 includes the dielectric layer 500 of any one of the above embodiments.

[0139] The embodiment of the present application also provides a surface acoustic wave device 1000, which comprises a piezoelectric substrate 100, an interdigital transducer 200 and an auxiliary structure 300, the interdigital transducer 200 is arranged on the piezoelectric substrate 100; in the arrangement direction of two bus bars 10 of the interdigital transducer 200, the two bus bars 10 have a crossing area A1 between them, the crossing area A1 comprises a middle area A11 and edge areas A12 located at both ends of the middle area A11; wherein in the arrangement direction of each electrode finger 20 of the interdigital transducer 200, the crossing area A1 is an area in which each electrode finger 20 overlaps with each other; the electrode finger 20 comprises a widened part 21 located in the edge area A12; the auxiliary structure 400 is located in the edge area A12, the auxiliary structure 400 comprises a first area, a second area and a third area, the first area and the third area are respectively located on the two sides away from each other of the second area in the length extension direction of the electrode finger 20; wherein in the same edge area A12, the auxiliary structure 400 covers the widened part 21, and the projection of the second area in the top view direction overlaps with the widened part 21 along the length extension direction of the electrode finger 20.

[0140] The surface acoustic wave device 1000 of the above embodiment can adjust the acoustic impedance of the edge area A12, so that the acoustic impedance of the area provided with the widened part 21 is different from the acoustic impedance of the area provided with the auxiliary structure 400, thereby making the surface acoustic wave device 1000 not only be able to better suppress the high-order transverse mode, but also be able to better suppress the low-order transverse mode, so as to effectively suppress the transverse mode of the surface acoustic wave device 1000, as far as possible to reduce the adverse effects of the transverse mode on the surface acoustic wave device 1000, and effectively prevent energy leakage.

[0141] For example, the length of at least one of the first area and the third area in the length extension direction of the electrode finger 20 is less than 50% of the length of the second area in the length extension direction of the electrode finger 20.

[0142] For example, the related description of the acoustic impedance refers to any suitable embodiment described above, which will not be repeated here.

[0143] For example, the piezoelectric substrate 100 comprises the piezoelectric substrate 100 of any one of the above embodiments. The interdigital transducer 200 comprises the interdigital transducer 200 of any one of the above embodiments. The widened part 21 comprises the widened part 21 of any one of the above embodiments. The auxiliary structure 400 comprises the auxiliary structure 400 of any one of the above embodiments.

[0144] Exemplarily, the positional relationship of the auxiliary structure 400 can refer to the previous embodiments, which will not be repeated here.

[0145] The embodiment of the present application further provides a surface acoustic wave device 1000, comprising a piezoelectric substrate 100, an interdigital transducer 200 and an auxiliary structure 400, the interdigital transducer 200 is arranged on the piezoelectric substrate 100; in the arrangement direction of the two bus bars 10 of the interdigital transducer 200, the two bus bars 10 have a crossing area A1 between them, the crossing area A1 comprises a middle area A11 and edge areas A12 located at both ends of the middle area A11; wherein, in the arrangement direction of each electrode finger 20 of the interdigital transducer 200, the crossing area A1 is the area where each electrode finger 20 overlaps with each other; the electrode finger 20 comprises a widened part 21 located in the edge area A12; the auxiliary structure 400 is located in the edge area A12; wherein, the widened part 21 comprises a fourth area, a fifth area and a sixth area, the fourth area and the sixth area are respectively located on the two sides away from the fifth area in the length extension direction of the electrode finger 20; in the same edge area A12, the projection of the auxiliary structure 400 in the top view direction overlaps with the fifth area along the length extension direction of the electrode finger 20.

[0146] The surface acoustic wave device 1000 of the above embodiment can adjust the acoustic impedance of the edge area A12, so that the acoustic impedance of the area provided with the widened part 21 is different from the acoustic impedance of the area provided with the auxiliary structure 400, thereby making the surface acoustic wave device 1000 not only better suppress the high-order transverse mode, but also better suppress the low-order transverse mode, so as to effectively suppress the transverse mode of the surface acoustic wave device 1000, as far as possible to reduce the adverse effects of the transverse mode on the surface acoustic wave device 1000, and effectively prevent energy leakage.

[0147] Exemplarily, the length of at least one of the fourth area and the sixth area in the length extension direction of the electrode finger 20 is less than 50% of the length of the fifth area in the length extension direction of the electrode finger 20.

[0148] Exemplarily, the related description of the acoustic impedance can refer to any suitable one of the above embodiments, which will not be repeated here.

[0149] Exemplarily, the piezoelectric substrate 100 comprises the piezoelectric substrate 100 of any one of the above embodiments. The interdigital transducer 200 comprises the interdigital transducer 200 of any one of the above embodiments. The widened portion 21 comprises the widened portion 21 of any one of the above embodiments. The auxiliary structure 400 comprises the auxiliary structure 400 of any one of the above embodiments.

[0150] Exemplarily, the positional relationship of the interdigital transducer 200 or the widened portion 21 can refer to the above embodiments, which will not be repeated here.

[0151] The embodiments of the present application further provide a filter comprising the surface acoustic wave device 1000 of any one of the above embodiments.

[0152] Exemplarily, the filter comprises a plurality of surface acoustic wave devices 1000, wherein at least one of the surface acoustic wave devices 1000 comprises the surface acoustic wave device 1000 of any one of the above embodiments. The structures of the surface acoustic wave devices 1000 can be the same or different, which is not limited herein.

[0153] The embodiments of the present application further provide a radio frequency front-end module comprising the surface acoustic wave device 1000 of any one of the above embodiments.

[0154] In some embodiments, the radio frequency front-end module can be applied to an electronic device, which can include but is not limited to an LED panel, a tablet computer, a notebook computer, a computer, a navigator, a mobile phone, an electronic watch and other electronic devices or components with a PCB, which is not limited herein.

[0155] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "mechanically coupling", "coupling" should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected. It can be mechanically connected, or it can be electrically connected. It can be directly connected, or it can be indirectly connected through an intermediate medium. It can be the internal communication 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 those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0156] The above disclosure provides many different embodiments or examples for implementing different structures of the present application. In order to simplify the present application, components and settings of specific examples are described in the 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 numerals and / or reference letters in different examples, and such 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 present application provides examples of various specific processes and materials, but those skilled in the art can realize the application of other processes and / or the use of other materials.

[0157] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific method steps, features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the exemplary description 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 can be combined in any one or more embodiments or examples in a suitable manner.

[0158] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any skilled person in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed by 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 should be subject to the protection scope of the claims.

Claims

1. A surface acoustic wave device, characterized by, The surface acoustic wave device comprises: a piezoelectric substrate; an interdigital transducer provided on the piezoelectric substrate, wherein, in the arrangement direction of two bus bars of the interdigital transducer, the two bus bars have a crossing area between them, the crossing area comprises a middle area and edge areas located at both ends of the middle area, wherein, in the arrangement direction of each electrode finger of the interdigital transducer, the crossing area is an area in which each electrode finger overlaps with each other, and the electrode finger comprises a widened part located in the edge area; an auxiliary structure located in the edge area; wherein, in the same edge area, the projection of the widened part and the auxiliary structure in the top view direction is at least partially staggered in the length extension direction of the electrode finger, and the acoustic impedance of the area provided with the widened part is different from the acoustic impedance of the area provided with the auxiliary structure.

2. The SAW device of claim 1, wherein, In the crossing area, the average of the acoustic impedance of the area provided with the widened part and the acoustic impedance of the area provided with the auxiliary structure is E; the E is less than the acoustic impedance of the middle area.

3. The SAW device of claim 1, wherein, The surface acoustic wave device has at least one of the following characteristics: In the same edge area, the acoustic impedance of the area provided with the widened part is less than the acoustic impedance of the area not provided with the auxiliary structure and the widened part; In the same edge area, the acoustic impedance of the area provided with the auxiliary structure is less than the acoustic impedance of the area not provided with the auxiliary structure and the widened part; The acoustic impedance of the area provided with the auxiliary structure is less than the acoustic impedance of the area provided with the widened part.

4. The SAW device of claim 1, wherein, The acoustic impedance of one of the widened part and the auxiliary structure closer to the middle area is greater than the acoustic impedance of the other farther away from the middle area.

5. The SAW device according to any one of claims 1 to 4, characterized in that The length of the auxiliary structure in the arrangement direction of the two bus bars is L1, 0.01λ 6. The SAW device according to any one of claims 1 to 4, characterized in that The thickness of the auxiliary structure is H1, 0.002λ 7. The SAW device according to any one of claims 1 to 4, characterized in that The length of the widened part in the arrangement direction of the two bus bars is L2, 0 8. The SAW device according to any one of claims 1 to 4, characterized by The thickness of the widened part is equal to the thickness of the electrode finger located in the middle area.

9. The SAW device according to any one of claims 1 to 4, characterized in that The width of the auxiliary structure in the arrangement direction of each electrode finger is W1, and the width of the electrode finger in the arrangement direction of each electrode finger is W3, W1≥W3 / 2.

10. The SAW device according to any one of claims 1 to 4, characterized by In the same edge area, the width of the widened part in the arrangement direction of each electrode finger is W2, the width of the electrode finger in the arrangement direction of each electrode finger is W3, and the center distance between adjacent two electrode fingers is P3, W3≤W2<(2P3-W3).

11. The SAW device according to any one of claims 1 to 4, characterized by The auxiliary structure is provided on the side of the interdigital transducer facing the piezoelectric substrate; or, the auxiliary structure is provided on the side of the interdigital transducer away from the piezoelectric substrate.

12. The SAW device according to any one of claims 1 to 4, characterized by In the same edge area, the projection of the widened part and the auxiliary structure corresponding to the same electrode finger in the top view direction is adjacent in the length extension direction of the electrode finger; Or, In the same edge region, the projection of the widened portion and the auxiliary structure corresponding to the same electrode finger in the top view direction is arranged apart along the length extension direction of the electrode finger; Or, In the same edge region, the projection of the widened portion and the auxiliary structure corresponding to the same electrode finger in the top view direction is partially overlapped along the length extension direction of the electrode finger.

13. The SAW device of claim 12, wherein, In the same edge region, the projection of the widened portion and the auxiliary structure corresponding to the same electrode finger in the top view direction is arranged apart by a preset distance L3 along the length extension direction of the electrode finger, L3 < 2.6λ, λ being the period of the electrode finger; or, In the same edge region, the projection of the widened portion and the auxiliary structure corresponding to the same electrode finger in the top view direction is overlapped by a preset distance L4 along the length extension direction of the electrode finger, L4 < 2.6λ, λ being the period of the electrode finger.

14. The SAW device of any of claims 1-4, wherein, In the same edge region, the widened portion is farther away from the intermediate region than at least part of the auxiliary structure; or, In the same edge region, the widened portion is closer to the intermediate region than at least part of the auxiliary structure.

15. The SAW device of any of claims 1-4, wherein, The auxiliary structure is arranged on the side of the electrode finger facing the piezoelectric substrate; or, The auxiliary structure is arranged on the side of the electrode finger and / or the widened portion away from the piezoelectric substrate.

16. The SAW device of any one of claims 1-4, wherein, In the top view direction, the auxiliary structure is arranged apart from or in contact with the electrode finger.

17. The SAW device of any of claims 1-4, wherein, The auxiliary structure comprises a plurality of auxiliary blocks, and in the arrangement direction of the electrode fingers, the auxiliary blocks are arranged apart in sequence; and the projection of each electrode finger and each auxiliary block in the top view direction is at least partially overlapped.

18. The SAW device of any one of claims 1-4, wherein, The projection of the auxiliary structure and each electrode finger in the top view direction is overlapped in the arrangement direction of the electrode fingers, and the projection of the auxiliary structure and the gap between any two adjacent electrode fingers in the top view direction is overlapped.

19. The SAW device of any one of claims 1-4, wherein, The auxiliary structure is a conductive structure or a non-conductive structure.

20. The SAW device of any one of claims 1-4, wherein, The surface acoustic wave device further comprises: A dielectric layer covering the interdigital transducer, and arranged on the side of the electrode finger away from the piezoelectric substrate.

21. The SAW device of claim 20, wherein, The dielectric layer is a temperature compensation layer.

22. The SAW device of claim 20, wherein, The auxiliary structure is arranged on the side of the dielectric layer away from the electrode finger; or, The dielectric layer is arranged on the side of the auxiliary structure away from the electrode finger.

23. The SAW device of any one of claims 1-4, wherein, The piezoelectric substrate comprises a piezoelectric film and a substrate arranged in layers, and the interdigital transducer is arranged on the surface of the piezoelectric film away from the substrate.

24. The SAW device of any one of claims 1-4, wherein, The interdigital transducer further comprises: A dummy finger, one end of which is connected to one of the bus bars, and the other end is arranged apart from the tip of the electrode finger connected to the other bus bar.

25. A surface acoustic wave device, characterized by, The surface acoustic wave device comprises: A piezoelectric substrate; An interdigital transducer arranged on the piezoelectric substrate; in the arrangement direction of the two bus bars of the interdigital transducer, the two bus bars have a crossing region between them, the crossing region comprises an intermediate region and edge regions located at both ends of the intermediate region; wherein, in the arrangement direction of each electrode finger of the interdigital transducer, the crossing region is the region where each electrode finger overlaps with each other; the electrode finger comprises a widened portion located in the edge region; The auxiliary structure is provided with the widened portion and the auxiliary structure in at least one of the two edge regions; The projection of the widened portion and the auxiliary structure in the top view direction is at least partially staggered in the length extension direction of the electrode finger within the same edge region; The auxiliary structure is a conductive structure, and the auxiliary structure comprises a plurality of auxiliary blocks, and each auxiliary block is sequentially and spacedly arranged in the arrangement direction of each electrode finger; each electrode finger is arranged in contact with an auxiliary block in the top view direction; A dielectric layer is arranged on the piezoelectric substrate and covers the interdigital transducer and the auxiliary structure.

26. A surface acoustic wave device, characterized by The surface acoustic wave device comprises: A piezoelectric substrate; An interdigital transducer is arranged on the piezoelectric substrate; in the arrangement direction of the two bus bars of the interdigital transducer, the two bus bars have a crossing region between them, and the crossing region comprises a middle region and edge regions located at both ends of the middle region; in the arrangement direction of each electrode finger of the interdigital transducer, the crossing region is an area in which each electrode finger overlaps each other; the electrode finger comprises a widened portion located in the edge region; An auxiliary structure is provided with the widened portion and the auxiliary structure in at least one of the two edge regions; The projection of the widened portion and the auxiliary structure in the top view direction is at least partially staggered in the length extension direction of the electrode finger within the same edge region; the auxiliary structure is a non-conductive structure; in the top view direction, a dielectric layer is arranged between the auxiliary structure and the interdigital transducer.

27. A surface acoustic wave device, characterized by, The surface acoustic wave device comprises: A piezoelectric substrate; An interdigital transducer is arranged on the piezoelectric substrate; in the arrangement direction of the two bus bars of the interdigital transducer, the two bus bars have a crossing region between them, and the crossing region comprises a middle region and edge regions located at both ends of the middle region; in the arrangement direction of each electrode finger of the interdigital transducer, the crossing region is an area in which each electrode finger overlaps each other; the electrode finger comprises a widened portion located in the edge region; An auxiliary structure is located in the edge region, and the auxiliary structure comprises a first region, a second region and a third region, and the first region and the third region are respectively located on the two sides away from each other of the second region in the length extension direction of the electrode finger; In the same edge region, the second region overlaps the widened portion in the length extension direction of the electrode finger in the top view direction.

28. A surface acoustic wave device, characterized by The surface acoustic wave device comprises: A piezoelectric substrate; An interdigital transducer is arranged on the piezoelectric substrate; in the arrangement direction of the two bus bars of the interdigital transducer, the two bus bars have a crossing region between them, and the crossing region comprises a middle region and edge regions located at both ends of the middle region; in the arrangement direction of each electrode finger of the interdigital transducer, the crossing region is an area in which each electrode finger overlaps each other; the electrode finger comprises a widened portion located in the edge region; An auxiliary structure is located in the edge region; The widened portion comprises a fourth region, a fifth region and a sixth region, the fourth region and the sixth region are respectively located on two sides of the fifth region in the length extension direction of the electrode finger; In the same edge region, the projection of the auxiliary structure in the top view direction overlaps with the fifth region in the length extension direction of the electrode finger.

29. A filter, characterized by A surface acoustic wave device comprising any one of claims 1-28.

30. A radio frequency front end module, comprising: A surface acoustic wave device comprising any one of claims 1-28.

Images