Interdigital transduction structure, filter structure and electronic device

Abstract

The invention provides an interdigital transduction structure, a filter structure and an electronic device. The interdigital transduction structure comprises a plurality of first electrode strips and second electrode strips which are arranged between two bus bars at intervals; the weighting connecting strip is located in the monopole area, and a preset distance exists between the projection of the load structure on the electrode strip and the edge of the free end of the electrode strip in the second direction. The weighting connecting strip is arranged in the monopole area, and the load structure is arranged in the interdigital area, so that the transverse mode in the radio frequency filter band is inhibited, and the loss is reduced; meanwhile, by arranging the weighting connecting strips in a staggered mode, the transverse mode is further restrained; in addition, the arrangement of a weighting connecting column, a sub weighting part and an auxiliary weighting part is matched, so that the inhibition effect on a transverse mode is further improved; and finally, a load structure is used as a weight increasing transverse strip or a primary weight increasing part, so that the inhibition effect on a transverse mode is further improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor integrated circuit manufacturing, and in particular relates to an interdigital transducer structure, a filter structure and an electronic device. Background Art

[0002] As communication technology develops from 2G to 5G, the number of communication frequency bands has gradually increased (from 4 frequency bands in 2G to more than 50 frequency bands in 5G). In order to improve the compatibility of smartphones with different communication standards, the amount of filters required for 5G smartphones will increase significantly, driving large-scale growth in the filter market. The RF filter currently widely used in wireless communication terminals is the SAW filter, which is responsible for filtering the RF signals of the receiving and transmitting channels and outputting signals of specific frequencies from the input multiple RF signals. At the same time, with the continuous development of mobile communication technology and the modularization of RF front-ends, the popularization of high-end applications has led to a trend of more complex, high-end, and miniaturized filters.

[0003] Ordinary SAW (Surface Acoustic Wave) filters are currently widely used in RF filters. However, for high-end devices, the performance degradation of ordinary SAW structures caused by the lateral mode is difficult to meet the requirements of RF front-end chips. Ordinary SAW is a conventional design method, and its structure is as follows Figure 1 As shown, it only includes ordinary bus bars 61 and interdigitated electrode bars 62. Ordinary SAW as a resonator and radio frequency filter will produce a strong lateral mode, which cannot meet the low insertion loss requirements for the design of high-end devices.

[0004] Therefore, there is an urgent need for a filter structure that can effectively suppress the transverse mode of SAW in radio frequency applications.

[0005] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solutions of the present application and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because these solutions are described in the background technology part of the present application. Summary of the invention

[0006] In view of the above shortcomings of the prior art, an object of the present invention is to provide an interdigital transducer structure, a filter structure and an electronic device for solving the problem of large insertion loss and poor performance of the lateral mode of the surface acoustic wave filter in radio frequency applications in the prior art.

[0007] To achieve the above object, the present invention provides an interdigital transducer structure, the interdigital transducer structure comprising: a bus bar, an electrode bar, a weighted connecting bar and a load structure;

[0008] The bus bar includes a first bus bar and a second bus bar arranged in parallel, and the electrode bar includes a first electrode bar and a second electrode bar; a plurality of the first electrode bars are arranged on the first bus bar, a plurality of the second electrode bars are arranged on the second bus bar, and the plurality of the first electrode bars and the plurality of the second electrode bars are arranged relatively spaced apart in a middle area between the first bus bar and the second bus bar; the end of the electrode bar connected to the bus bar is a connecting end, and the end of the electrode bar away from the connecting end is a free end;

[0009] A direction parallel to the first bus bar is a first direction, a direction perpendicular to the first direction and parallel to the plane where the interdigital transducer structure is located is a second direction, and a third direction is perpendicular to both the first direction and the second direction;

[0010] The middle region includes an interdigital region and a unipolar region not belonging to the interdigital region, wherein the interdigital region is a region formed between an edge of a free end of the first electrode strip and an edge of a free end of the second electrode strip;

[0011] The weighted connecting bar is located in the monopolar region, and the weighted connecting bar is located between the free end of the first electrode bar and the second bus bar, and / or between the free end of the second electrode bar and the first bus bar;

[0012] There is a preset distance in the second direction between the projection of the load structure on the electrode strip and the edge of the free end of the electrode strip.

[0013] Optionally, the load structure is a primary weighting part, which is respectively located on the surface of the free end of the first electrode strip, and / or the surface of the second electrode strip at a position corresponding to the free end of the first electrode strip in the first direction, and / or the surface of the free end of the second electrode strip, and / or the surface of the first electrode strip at a position corresponding to the free end of the second electrode strip in the first direction.

[0014] Optionally, each of the primary weight portions includes at least two sub-weight portions arranged along the second direction.

[0015] Optionally, the weighted connecting bar includes a first weighted connecting bar and a second weighted connecting bar, and the second weighted connecting bar is connected to the second bus bar at a position corresponding to the first electrode bar along the second direction through a weighted connecting column, and the first weighted connecting bar is connected to the first bus bar at a position corresponding to the second electrode bar along the second direction through a weighted connecting column.

[0016] Optionally, a secondary weighting portion is provided on each of the weighted connecting columns.

[0017] Optionally, the load structure is a weighted horizontal bar, which is parallel to the first direction, one of the weighted horizontal bars is arranged on the surface of the free end of the first electrode strip in the second direction, and the other weighted horizontal bar is arranged on the surface of the free end of the second electrode strip in the second direction.

[0018] Optionally, in the interdigitated area, an auxiliary weighting portion is provided on the first electrode strip and the second electrode strip near the two weighting horizontal strips; the auxiliary weighting portion is provided between the two weighting horizontal strips, or the auxiliary weighting portion is not provided between the two weighting horizontal strips.

[0019] Optionally, the weighted connecting strips include a first weighted connecting strip and a second weighted connecting strip, the projections of the first weighted connecting strip in the first direction overlap, and the projections of the second weighted connecting strip in the first direction overlap;

[0020] The lengths of the first weighted connecting strip and the second weighted connecting strip in parallel to the second direction are both 0.02λ-0.25λ, the minimum distance between each free end and the weighted connecting strip closest to it in parallel to the second direction is 0.02λ-0.4λ, and the minimum distance between each free end and the bus bar closest to it in parallel to the second direction is 1λ-2λ;

[0021] When the load structure is a primary weighting part, the projection of each primary weighting part on the plane where the interdigital transducer structure is located is located inside the projection of the electrode strip where each primary weighting part is located on the plane where the interdigital transducer structure is located, the length of the electrode strip where the primary weighting part is located in the first direction is greater than the length of the primary weighting part in the first direction, and the length of each primary weighting part parallel to the second direction is 0.5λ-1λ; λ is the wavelength of the surface acoustic wave propagating in the interdigital transducer structure.

[0022] Optionally, the weighted connecting strips include a first weighted connecting strip and a second weighted connecting strip, and two adjacent first weighted connecting strips along the first direction are staggered in the second direction so that the projections of the two adjacent first weighted connecting strips in the first direction do not overlap; and two adjacent second weighted connecting strips along the first direction are staggered in the second direction so that the projections of the two adjacent second weighted connecting strips in the first direction do not overlap.

[0023] Optionally, the minimum distances between two adjacent first weighted connecting strips along the first direction and their corresponding second electrode strips in the second direction are 0.02λ-0.4λ and 0.1λ-0.6λ respectively, the minimum distances between two adjacent second weighted connecting strips along the first direction and their corresponding first electrode strips in the second direction are 0.02λ-0.4λ and 0.1λ-0.6λ respectively, and the lengths of the first weighted connecting strip and the second weighted connecting strip parallel to the second direction are both 0.02λ-0.25λ; λ is the wavelength of surface acoustic waves propagating in the interdigital transducer structure.

[0024] The present invention also provides a filter structure, which includes any one of the above-mentioned interdigital transducer structures.

[0025] Optionally, the filter structure also includes two reflection grating arrays, which are respectively arranged on both sides of the interdigital transducer structure along the first direction, each of the reflection grating arrays is composed of at least two metal reflection strips and two auxiliary bus bars, the metal reflection strips are parallel to the second direction and arranged along the first direction, and each of the metal reflection strips is respectively in contact with the two auxiliary bus bars at both ends in the second direction, and a reflection grating load structure is arranged on the reflection grating array at a position that coincides with the projection of the load structure of the interdigital transducer structure in the first direction.

[0026] Optionally, when the load structure of the interdigital transduction structure is a primary weighting part, the reflective grating load structure is also a primary weighting part, and the primary weighting part of the reflective grating array is located at a position on the metal reflective strip corresponding to the primary weighting part of the interdigital transduction structure in the first direction.

[0027] Optionally, when the primary weighting portion of the interdigital transduction structure is at least two sub-weighting portions, each primary weighting portion on the metal reflection strip is also at least two sub-weighting portions arranged along the second direction, and the sub-weighting portions of the reflection grating array are located at positions on the metal reflection strip corresponding to the sub-weighting portions of the interdigital transduction structure in the first direction.

[0028] When the load structure of the IDT structure is a weighted bar, the reflective grating load structure is also a weighted bar. The weighted bar of the reflective grating array is connected to the weighted bar of the IDT structure and their projections in the first direction overlap.

[0029] When the interdigital transducing structure is provided with an auxiliary weighting portion, the reflective grating array is also provided with an auxiliary weighting portion, and the auxiliary weighting portion of the reflective grating array is located at a position on the metal reflective strip corresponding to the auxiliary weighting portion of the interdigital transducing structure in the first direction.

[0030] The present invention further provides an electronic device, comprising any one of the filter structures described above.

[0031] As described above, the interdigital transducer structure, filter structure and electronic device of the present invention have the following beneficial effects:

[0032] The present invention suppresses the transverse mode in the band of the radio frequency filter and reduces the loss by arranging a weighted connecting strip in the monopole region and arranging a load structure in the interdigital region;

[0033] Furthermore, a load structure arranged in the interdigital area has a preset distance in the second direction between its projection on the electrode strip and the edge of the free end of the electrode strip, which can make the lateral mode suppression effect within the RF filter band better and the flatness within the passband better, further improve the characteristics of the RF filter, and enhance the performance of the RF filter.

[0034] The present invention further suppresses the lateral mode by staggering the weighted connecting strips;

[0035] The present invention cooperates with the arrangement of the weighted connecting column, the sub-weighted portion and the auxiliary weighted portion to further improve the suppression effect of the lateral mode;

[0036] The present invention further improves the suppression effect of the transverse mode by using the load structure as a weighted horizontal bar or a primary weighted part. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram showing the structure of a common SAW in the prior art.

[0038] Figure 2 It shows a schematic structural diagram of the interdigital transducer structure with a primary weighting part in Example 1 of the present invention.

[0039] Figure 3 It shows a comparison diagram of the resonance curves of the filters obtained by the interdigital transducer structure in the prior art and in Example 1.

[0040] Figure 4 It shows a comparison diagram of the resonance curves of the filters obtained by the interdigital transducer structure in the prior art and in Example 1.

[0041] Figure 5 It shows a comparison diagram of the resonance curves of the filters obtained by the interdigital transducer structure in the prior art and in Example 1.

[0042] Figure 6 It shows a comparison diagram of the resonance curves of the filters obtained by the interdigital transducer structure in the prior art and in Example 1.

[0043] Figure 7It shows a comparison diagram of the resonance curves of the filters obtained by the interdigital transducer structure in the prior art and in Example 1.

[0044] Figure 8 It shows an enlarged schematic diagram of the structure of the interdigital transducer structure with a primary weighting portion in Example 1 of the present invention.

[0045] Fig. 9 It shows a schematic structural diagram of an interdigital transducer structure with staggered distribution of weighted connecting strips in an optional example of Embodiment 1 of the present invention.

[0046] Fig.10 It shows an enlarged schematic diagram of the structure of the interdigital transducer structure with staggered distribution of weighted connecting strips in an optional example of Embodiment 1 of the present invention.

[0047] Fig.11 It shows a schematic structural diagram of an interdigital transducer structure with a sub-weighting portion in Embodiment 2 of the present invention.

[0048] Fig.12 It shows an enlarged schematic diagram of the structure of the interdigital transducer structure with a sub-weighting portion in Example 2 of the present invention.

[0049] Fig.13 It shows a schematic diagram of the structure of an interdigital transducer structure with staggered distribution of weighted connecting strips in an optional example of Embodiment 2 of the present invention.

[0050] Fig.14 It shows an enlarged schematic diagram of the structure of the interdigital transducer structure with staggered distribution of weighted connecting strips in an optional example of Embodiment 2 of the present invention.

[0051] Fig.15 It is a schematic structural diagram of an interdigital transducer structure with a weighted connecting column in Example 3 of the present invention.

[0052] Fig.16 It is a schematic diagram of the enlarged structure of the interdigital transducer structure with a weighted connecting column in Example 3 of the present invention.

[0053] Fig.17 It shows a schematic diagram of the structure of the interdigital transducer structure with a secondary weighting portion in Example 4 of the present invention.

[0054] Fig.18 It shows an enlarged schematic diagram of the structure of the interdigital transducer structure with a secondary weighting portion in Example 4 of the present invention.

[0055] Fig.19 It shows a schematic structural diagram of an interdigital transducer structure with a weighted horizontal bar in Example 5 of the present invention.

[0056] Fig. 20It is a schematic diagram of the enlarged structure of the interdigital transducer structure with the weighted horizontal strip in Example 5 of the present invention.

[0057] Fig.21 It shows a schematic structural diagram of an interdigital transducer structure with staggered distribution of weighted connecting strips in an optional example of Embodiment 5 of the present invention.

[0058] Fig. 22 It shows an enlarged schematic diagram of the structure of the interdigital transducer structure with staggered distribution of weighted connecting strips in an optional example of Embodiment 5 of the present invention.

[0059] Fig.23 It shows a schematic diagram of the structure of the interdigital transducer structure provided with an auxiliary weighting portion in Example 6 of the present invention.

[0060] Fig.24 It shows an enlarged schematic diagram of the structure of the interdigital transducer structure provided with an auxiliary weighting portion in Example 6 of the present invention.

[0061] Fig.25 It shows a schematic structural diagram of an interdigital transducer structure with staggered distribution of weighted connecting strips in an optional example of Embodiment 6 of the present invention.

[0062] Fig.26 It shows an enlarged schematic diagram of the structure of the interdigital transducer structure with staggered distribution of weighted connecting strips in an optional example of Embodiment 6 of the present invention.

[0063] Fig. 27 Shown is a structural schematic diagram of the filter structure in an optional example of Embodiment 7 of the present invention.

[0064] Component number description

[0065] A, unipolar region; B, interdigitated region;

[0066] 11. first bus bar; 12. second bus bar;

[0067] 21. first electrode strip; 22. second electrode strip; 23. connection end; 24. free end;

[0068] 31. First weighted connecting strip; 32. Second weighted connecting strip;

[0069] 40. Reflection grid array; 41. Auxiliary bus bar; 42. Metal reflective strip;

[0070] 51. Primary weighting part; 52. Sub-weighting part; 53. Weighting connecting column; 54. Secondary weighting part; 55. Weighting horizontal bar; 56. Auxiliary weighting part;

[0071] 61. Ordinary bus bar; 62. Interdigitated electrode bar. DETAILED DESCRIPTION

[0072] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0073] For example, when describing the embodiments of the present invention in detail, for the sake of convenience, the schematic diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0074] For convenience of description, spatially relative terms such as "under", "below", "below", "below", "above", "on", etc. may be used herein to describe the relationship of one element or feature shown in the drawings to other elements or features. It will be understood that these spatially relative terms are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the drawings.

[0075] In the context of the present application, a structure in which a first feature is described as being "above" a second feature may include embodiments in which the first and second features are in direct contact, and may also include embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0076] It should be noted that the illustrations provided in the various embodiments of the present invention are only used to schematically illustrate the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention rather than being drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout type may also be more complicated.

[0077] The “first direction” involved in the present invention is the x direction shown in the figure, the “second direction” is the y direction shown in the figure, and the “third direction” is the direction perpendicular to the paper plane and is not shown in the figure. The directions defined here are only for the convenience of illustration. The actual reference system of the directions can be set according to the application and are all within the protection scope of the present invention.

[0078] Numerical ranges in the context of the present invention all include the limits of the range.

[0079] Embodiment 1:

[0080] like Figure 2As shown, this embodiment provides an interdigital transducer structure, which includes: a bus bar, an electrode bar, a weighted connecting bar and a load structure;

[0081] The bus bar includes a first bus bar 11 and a second bus bar 12 arranged in parallel, and the electrode bar includes a first electrode bar 21 and a second electrode bar 22; a plurality of the first electrode bars 21 are arranged on the first bus bar 11, and a plurality of the second electrode bars 22 are arranged on the second bus bar 12, and the plurality of the first electrode bars 21 and the plurality of the second electrode bars 22 are arranged relatively and spaced in the middle area between the first bus bar 11 and the second bus bar 12; the end of the electrode bar connected to the bus bar is a connecting end 23, and the end of the electrode bar away from the connecting end 23 is a free end 24; the direction parallel to the first bus bar 11 is a first direction, the direction perpendicular to the first direction and parallel to the plane where the interdigital transducer structure is located is a second direction, and the third direction is perpendicular to both the first direction and the second direction;

[0082] The middle region includes an interdigital region B and a unipolar region A not belonging to the interdigital region B, wherein the interdigital region B is a region formed between an edge of a free end 24 of the first electrode strip 21 and an edge of a free end 24 of the second electrode strip 22;

[0083] The weighted connecting bar is located in the monopolar region A, and the weighted connecting bar is located between the free end 24 of the first electrode bar 21 and the second bus bar 12, and / or between the free end 24 of the second electrode bar 12 and the first bus bar 11;

[0084] There is a preset distance in the second direction between the projection of the load structure on the electrode strip and the edge of the free end 24 of the electrode strip.

[0085] The present invention arranges the load structure on the two end surfaces of the interdigital region B along the second direction, and adjusts the sound velocity of the monopolar region A and the interdigital region B through the load structure, thereby realizing maximum suppression of the transverse mode ripples; in addition, by arranging a preset distance between the projection of the load structure on the electrode strip and the edge of the free end 24 in the second direction, the cost required for the load structure is reduced, while avoiding the risk of short circuit between the electrode strips due to the existence of the load structure.

[0086] In addition, after testing, in the comparative test, by comparing whether there is a preset distance in the second direction between the projection of the load structure on the electrode strip and the edge of the free end 24, the presence of a preset distance in the second direction between the projection of the load structure on the electrode strip and the edge of the free end 24 is better than the absence of a preset distance in the second direction between the projection of the load structure on the electrode strip and the edge of the free end 24 (that is, the projection of the load structure on the electrode strip coincides with the edge of the free end 24, for example, the load structure is set on the edge of the free end, and the distance from the edge is zero), which can make the lateral mode suppression effect within the RF filter band better, the flatness in the passband better, and further improve the characteristics of the RF filter, so that the performance of the RF filter is improved. Specifically, Figure 2 The figure shows that the weighted connecting bar is provided between the free end 24 of the first electrode bar 21 and the second bus bar 12, and between the free end 24 of the second electrode bar 22 and the first bus bar 11. The weighted connecting bar may also be provided at only one of the locations.

[0087] In one embodiment, the load structure may be on the upper surface and / or the lower surface of the electrode strip, such as Figure 2 Shown is a schematic diagram of the structure of the load structure on the upper surface of the electrode strip.

[0088] In one embodiment, an additional layer is provided between the load structure and the electrode strips.

[0089] In one embodiment, the additional layer is a temperature compensation layer and / or a passivation layer.

[0090] In one embodiment, the load structure is a primary weighting portion 51, and the primary weighting portion 51 is respectively located on the surface of the free end 24 of the first electrode strip 21, and / or the surface of the second electrode strip 22 at a position corresponding to the free end 24 of the first electrode strip 21 in the first direction, and / or the surface of the free end 24 of the second electrode strip 22, and / or the surface of the first electrode strip 21 at a position corresponding to the free end 24 of the second electrode strip 22 in the first direction.

[0091] Specifically, Figure 2 The figure shows the case where the primary weighting portion 51 is set in all four positions. The primary weighting portion 51 can also be set in any one of the four positions or any combination of more than one of them. The selection can be adjusted according to the cost and performance requirements of the SAW, all of which belong to the protection scope of the present invention.

[0092] Specifically, the surface of the primary weighting part 51 includes an upper surface and / or a lower surface, or an additional layer is provided between the surface and the primary weighting part 51. The additional layer may be a temperature compensation layer and / or a passivation layer, etc., all of which belong to the protection scope of the present invention. Figure 2 FIG. 1 is a schematic diagram showing the structure of the primary weighting portion 51 on the upper surface of the electrode strip.

[0093] The present invention further improves the acoustic wave propagation properties between the monopole region A and the interdigital region B by arranging the primary weighting portion 51 on the surface of the free end 24 in the interdigital region B and the corresponding electrode strip surface, thereby further suppressing the transverse mode of the surface acoustic wave filter, reducing the loss and improving the quality factor. Figure 3-Figure 5 The figure shows the comparison of the resonance curves of the ordinary SAW in the prior art and the configuration of the weighted connecting strip and the primary weighted portion 51 in the present invention, wherein the prior art is represented by a dotted line and the solution of the present invention is represented by a solid line. It can be seen that compared with the prior art, the solution of the present invention greatly reduces the burrs and splitting phenomena in the resonance curve. Experiments have shown that the suppression effect of a single weighted connecting strip and the primary weighted portion 51 on the transverse mode ripple is better than that of multiple weighted connecting strips. Figure 6-Figure 7 Shown is a resonance curve diagram comparing a normal SAW (dotted line curve in the figure), a SAW with only a primary weighting portion 51 (dashed line curve in the figure), and a filter with a primary weighting portion 51 and a single weighting connecting strip (solid line curve in the figure). It can be seen that the resonance curve of the filter with a primary weighting portion 51 and a single weighting connecting strip is the smoothest, the burr phenomenon is minimal, the loss on both sides of the passband is smaller, and the quality factor obtained is the highest.

[0094] In one embodiment, Figure 8 The load structure is an enlarged view of the interdigital transducer structure of the primary weighted portion 51, wherein the weighted connecting strips include a first weighted connecting strip 31 and a second weighted connecting strip 32, wherein the projections of the first weighted connecting strip 31 in the first direction overlap, and the projections of the second weighted connecting strip 32 in the first direction overlap;

[0095] The lengths CB of the first weighted connecting bar 31 and the second weighted connecting bar 32 in parallel to the second direction are both 0.02λ-0.25λ, the minimum distance Gap2 between each free end 24 and the weighted connecting bar closest to it in parallel to the second direction is 0.02λ-0.4λ, and the minimum distance Gap1 between each free end 24 and the bus bar closest to it in parallel to the second direction is 1λ-2λ;

[0096] The projection of each of the primary weighted portions 51 on the plane where the interdigital transducer structure is located is located inside the projection of the electrode strip where each of the primary weighted portions 51 is located on the plane where the interdigital transducer structure is located, the length of the electrode strip where the primary weighted portion 51 is located in the first direction is greater than the length of the primary weighted portion 51 in the first direction, and the length Piston of each of the primary weighted portions 51 in parallel to the second direction is 0.5λ-1λ;

[0097] The projection of each of the primary weighted portions 51 on the plane where the interdigital transducer structure is located is located inside the projection of the electrode strip where each of the primary weighted portions 51 is located on the plane where the interdigital transducer structure is located, the length of the electrode strip where the primary weighted portion 51 is located in the first direction is greater than the length of the primary weighted portion 51 in the first direction, the minimum distance Gap3 between each of the primary weighted portions 51 and the edge of the electrode strip where each of the primary weighted portions 51 is located parallel to the first direction is 0.005λ-0.03λ, and the minimum distance Gap4 between each of the primary weighted portions 51 and the edge of the electrode strip where each of the primary weighted portions 51 is located parallel to the second direction is 0.005λ-0.03λ;

[0098] λ is the wavelength of the surface acoustic wave propagating in the interdigital transducer structure.

[0099] The present invention further optimizes the sound wave propagation mode and reduces the transverse mode ripples by setting the width of the primary weighting part 51 smaller than the electrode strips. While optimizing the SAW performance, the primary weighting part 51 required to be used is reduced, the weight required for the filter is reduced, and the application of SAW miniaturization and lightness is facilitated.

[0100] In one embodiment, the primary weight portion 51 is a laminated structure of chromium, copper, and chromium from top to bottom along the third direction; or the primary weight portion 51 is a laminated structure of chromium, silver, and chromium from top to bottom along the third direction.

[0101] The present invention further optimizes the suppression of the lateral mode by the primary weight part 51 by setting the material of the primary weight part 51 to a laminated structure of chromium / copper / chromium or chromium / silver / chromium. Experiments on various materials have shown that the laminated structures of chromium / copper / chromium and chromium / silver / chromium as the material of the primary weight part 51 can achieve the best performance and improve the adhesion of the primary weight part 51 on the electrode strip.

[0102] In one embodiment, Fig. 9As shown, the weighted connecting strips include a first weighted connecting strip 31 and a second weighted connecting strip 32. The two adjacent first weighted connecting strips 31 along the first direction are staggered in the second direction so that the projections of the two adjacent first weighted connecting strips 31 in the first direction do not overlap; the two adjacent second weighted connecting strips 32 along the first direction are staggered in the second direction so that the projections of the two adjacent second weighted connecting strips 32 in the first direction do not overlap.

[0103] The present invention further improves the influence of the weighted connecting strips on the acoustic wave propagation properties between the monopole region A and the interdigital region B by coordinating the structure of the staggered distribution of the weighted connecting strips, and further optimizes the suppression effect on the transverse mode.

[0104] In one embodiment, Fig.10 The figure shows an enlarged view of the interdigital transducer structure in which the weighted connecting strips 31 are staggeredly distributed. The minimum distances Gap5 and Gap6 between two adjacent first weighted connecting strips 31 and their corresponding second electrode strips 22 along the first direction are 0.02λ-0.4λ and 0.1λ-0.6λ respectively. The minimum distances Gap5 and Gap6 between two adjacent second weighted connecting strips 32 and their corresponding first electrode strips 21 along the first direction are 0.02λ-0.4λ and 0.1λ-0.6λ respectively. The lengths CB1 and CB2 of the first weighted connecting strip 31 and the second weighted connecting strip 32 in parallel to the second direction are both 0.02λ-0.25λ. The minimum distance Gap1 between each free end 24 and the bus bar closest to it in parallel to the second direction is 1λ-2λ.

[0105] The projection of each of the primary weighted portions 51 on the plane where the interdigital transducer structure is located is located inside the projection of the electrode strip where each of the primary weighted portions 51 is located on the plane where the interdigital transducer structure is located, the length of the electrode strip where the primary weighted portion 51 is located in the first direction is greater than the length of the primary weighted portion 51 in the first direction, and the length Piston of each of the primary weighted portions 51 in parallel to the second direction is 0.5λ-1λ;

[0106] The projection of each primary weighting portion 51 on the plane where the interdigital transducer structure is located is located inside the projection of the electrode strip where each primary weighting portion 51 is located on the plane where the interdigital transducer structure is located, the length of the electrode strip where the primary weighting portion 51 is located in the first direction is greater than the length of the primary weighting portion 51 in the first direction, the minimum distance Gap3 between each primary weighting portion 51 and the edge of the electrode strip where each primary weighting portion 51 is located parallel to the first direction is 0.005λ-0.03λ, and the minimum distance Gap4 between each primary weighting portion 51 and the edge of the electrode strip where each primary weighting portion 51 is located parallel to the second direction is 0.005λ-0.03λ; λ is the wavelength of the surface acoustic wave propagating in the interdigital transducer structure.

[0107] In one embodiment, projections of two spaced-apart first weighted connecting strips 31 in the first direction overlap, and / or projections of two spaced-apart second weighted connecting strips 32 in the first direction overlap.

[0108] In one embodiment, projections of two spaced-apart first weighted connecting strips 31 in the first direction do not overlap, and / or projections of two spaced-apart second weighted connecting strips 32 in the first direction do not overlap.

[0109] This embodiment can also be combined with any one or more combinations of any features in other embodiments to obtain a new structure, and the obtained structures are all within the scope of protection of the present invention.

[0110] Embodiment 2:

[0111] This embodiment provides an IDT structure, which has the same other features as the IDT structure in Embodiment 1, except that:

[0112] Each of the primary weight portions 51 includes at least two sub-weight portions 52 arranged along the second direction.

[0113] The present invention further improves the primary emphasis portion 51 by dividing it into two sub-emphasis portions 52 , thereby further improving the acoustic wave propagation properties between the monopole region A and the interdigital region B and optimizing the suppression effect on the transverse mode.

[0114] In one embodiment, Fig.11 As shown, each of the primary weight portions 51 includes two sub-weight portions 52 arranged along the second direction.

[0115] In one embodiment, the plurality of sub-weighting parts 52 may be arranged in different arrays, and the specific arrangement may be adjusted according to actual structural requirements and experimental results.

[0116] In one embodiment, the weighted connecting strips include a first weighted connecting strip 31 and a second weighted connecting strip 32, the projections of the first weighted connecting strip 31 in the first direction overlap, and the projections of the second weighted connecting strip 32 in the first direction overlap;

[0117] like Fig.12 The figure shows an enlarged view of the interdigital transducer structure including at least two sub-weighted portions 52, wherein the lengths CB of the first weighted connecting strip 31 and the second weighted connecting strip 32 in parallel to the second direction are both 0.02λ-0.25λ, the minimum distance Gap2 between each free end 24 and the weighted connecting strip closest thereto in parallel to the second direction is 0.02λ-0.4λ, and the minimum distance Gap1 between each free end 24 and the bus bar closest thereto in parallel to the second direction is 1λ-2λ;

[0118] The projections of the two sub-weighted portions 52 on the plane where the interdigital transducer structure is located are located inside the projections of the electrode strips where the two sub-weighted portions 52 are located on the plane where the interdigital transducer structure is located, and the length of the electrode strips where the two sub-weighted portions 52 are located in the first direction is greater than the total length of the two sub-weighted portions 52 in the first direction;

[0119] The lengths Piston1 and Piston2 of the two sub-weighting portions 52 in the second direction are both 0.2λ-1λ, and the minimum distance Gap7 between the two sub-weighting portions 52 in the second direction is 0.1λ-1λ; the minimum distance Gap3 between each sub-weighting portion 52 and the edge of the electrode strip where each sub-weighting portion 52 is located parallel to the first direction is 0.005λ-0.03λ, and the minimum distance Gap4 between each sub-weighting portion 52 and the edge of the electrode strip where each sub-weighting portion 52 is located parallel to the second direction is 0.005λ-0.03λ;

[0120] λ is the wavelength of the surface acoustic wave propagating in the interdigital transducer structure.

[0121] In one embodiment, Fig.13 As shown, the weighted connecting strips include a first weighted connecting strip 31 and a second weighted connecting strip 32. The two adjacent first weighted connecting strips 31 along the first direction are staggered in the second direction so that the projections of the two adjacent first weighted connecting strips 31 in the first direction do not overlap; the two adjacent second weighted connecting strips 32 along the first direction are staggered in the second direction so that the projections of the two adjacent second weighted connecting strips 32 in the first direction do not overlap.

[0122] The present invention further improves the influence of the weighted connecting strips on the acoustic wave propagation properties between the monopole region A and the interdigital region B by coordinating the structure of the staggered distribution of the weighted connecting strips, and further optimizes the suppression effect on the transverse mode.

[0123] In one embodiment, Fig.14 The figure shows an enlarged view of the interdigital transducer structure in which the weighted connecting strips 31 are staggeredly distributed. The minimum distances Gap5 and Gap6 between two adjacent first weighted connecting strips 31 and their corresponding second electrode strips 22 along the first direction are 0.02λ-0.4λ and 0.1λ-0.6λ respectively. The minimum distances Gap5 and Gap6 between two adjacent second weighted connecting strips 32 and their corresponding first electrode strips 21 along the first direction are 0.02λ-0.4λ and 0.1λ-0.6λ respectively. The lengths CB1 and CB2 of the first weighted connecting strip 31 and the second weighted connecting strip 32 in parallel to the second direction are both 0.02λ-0.25λ. The minimum distance Gap1 between each free end 24 and the bus bar closest to it in parallel to the second direction is 1λ-2λ.

[0124] The projections of the two sub-weighted portions 52 on the plane where the interdigital transducer structure is located are located inside the projections of the electrode strips where the two sub-weighted portions 52 are located on the plane where the interdigital transducer structure is located, and the length of the electrode strips where the two sub-weighted portions 52 are located in the first direction is greater than the total length of the two sub-weighted portions 52 in the first direction;

[0125] The lengths Piston1 and Piston2 of the two sub-weighting portions 52 in the second direction are both 0.2λ-1λ, and the minimum distance Gap7 between the two sub-weighting portions 52 in the second direction is 0.1λ-1λ; the minimum distance Gap3 between each sub-weighting portion 52 and the edge of the electrode strip where each sub-weighting portion 52 is located parallel to the first direction is 0.005λ-0.03λ, and the minimum distance Gap4 between each sub-weighting portion 52 and the edge of the electrode strip where each sub-weighting portion 52 is located parallel to the second direction is 0.005λ-0.03λ;

[0126] λ is the wavelength of the surface acoustic wave propagating in the interdigital transducer structure.

[0127] In one embodiment, projections of two spaced-apart first weighted connecting strips 31 in the first direction overlap, and / or projections of two spaced-apart second weighted connecting strips 32 in the first direction overlap.

[0128] In one embodiment, projections of two spaced-apart first weighted connecting strips 31 in the first direction do not overlap, and / or projections of two spaced-apart second weighted connecting strips 32 in the first direction do not overlap.

[0129] This embodiment can also be combined with any one or more combinations of any features in other embodiments to obtain a new structure, and the obtained structures are all within the scope of protection of the present invention.

[0130] Embodiment 3:

[0131] This embodiment provides an IDT structure, which has the same other features as the IDT structure in Embodiment 1 or Embodiment 2, except that:

[0132] The weighted connecting bar includes a first weighted connecting bar 31 and a second weighted connecting bar 32. The second weighted connecting bar 32 is connected to the second bus bar 12 at a position corresponding to the first electrode bar 21 along the second direction through a weighted connecting column 53. The first weighted connecting bar 31 is connected to the first bus bar 11 at a position corresponding to the second electrode bar 22 along the second direction through a weighted connecting column 53.

[0133] The present invention further improves the acoustic wave propagation properties between the monopole region A and the interdigital region B and optimizes the suppression effect on the transverse mode by arranging a weighted connecting column 53 between the adjacent weighted connecting bars and the bus bar for connection.

[0134] In one embodiment, Fig.15 As shown, the weighted connecting strips include a first weighted connecting strip 31 and a second weighted connecting strip 32 , the projections of the first weighted connecting strip 31 in the first direction overlap, and the projections of the second weighted connecting strip 32 in the first direction overlap.

[0135] In one embodiment, Fig.16The figure shows an enlarged view of the interdigital transducer structure provided with the weighted connecting column 53, wherein the minimum distance Gap3 between each of the primary weighted portions 51 and the edge of the electrode strip where each of the primary weighted portions 51 is located parallel to the first direction is 0.005λ-0.03λ, and the minimum distance Gap4 between each of the primary weighted portions 51 and the edge of the electrode strip where each of the primary weighted portions 51 is located parallel to the second direction is 0.005λ-0.03λ; the length Pitch1 of the weighted connecting column 53 corresponding to the first electrode strip 21 in the first direction is the same as that of the first electrode strip 21, and the length Pitch1 of the weighted connecting column 53 corresponding to the second electrode strip 22 in the first direction is the same as that of the second electrode strip 22, and λ is the wavelength of the surface acoustic wave propagating in the interdigital transducer structure;

[0136] The lengths CB of the first weighted connecting bar 31 and the second weighted connecting bar 32 in parallel to the second direction are both 0.02λ-0.25λ, the minimum distance Gap2 between each free end 24 and the weighted connecting bar closest to it in parallel to the second direction is 0.02λ-0.4λ, and the minimum distance Gap1 between each free end 24 and the bus bar closest to it in parallel to the second direction is 1λ-2λ;

[0137] When the load structure is a primary weighting part 51, the projection of each primary weighting part 51 on the plane where the interdigital transducer structure is located is located inside the projection of the electrode strip where each primary weighting part 51 is located on the plane where the interdigital transducer structure is located, the length of the electrode strip where the primary weighting part 51 is located in the first direction is greater than the length of the primary weighting part 51 in the first direction, and the length Piston of each primary weighting part 51 in parallel to the second direction is 0.5λ-1λ;

[0138] λ is the wavelength of the surface acoustic wave propagating in the interdigital transducer structure.

[0139] In one embodiment, projections of two spaced-apart first weighted connecting strips 31 in the first direction overlap, and / or projections of two spaced-apart second weighted connecting strips 32 in the first direction overlap.

[0140] In one embodiment, projections of two spaced-apart first weighted connecting strips 31 in the first direction do not overlap, and / or projections of two spaced-apart second weighted connecting strips 32 in the first direction do not overlap.

[0141] This embodiment can also be combined with any one or more combinations of any features in other embodiments to obtain a new structure, and the obtained structures are all within the scope of protection of the present invention.

[0142] Embodiment 4:

[0143] This embodiment provides an IDT structure, which has the same other features as the IDT structure in Embodiment 3, except that:

[0144] A secondary weight portion 54 is provided on each of the weight connection columns 53 .

[0145] The present invention further improves the acoustic wave propagation properties between the monopole region A and the interdigital region B by arranging the secondary weighted portion 54 on the weighted connecting column 53, thereby optimizing the suppression effect on the transverse mode.

[0146] In one embodiment, Fig.17 As shown, the weighted connecting strips include a first weighted connecting strip 31 and a second weighted connecting strip 32 , the projections of the first weighted connecting strip 31 in the first direction overlap, and the projections of the second weighted connecting strip 32 in the first direction overlap.

[0147] In one embodiment, Fig.18 The figure shows an enlarged view of the interdigital transducer structure with the secondary weighted portion 54, wherein the length Piston3 of the secondary weighted portion 54 in the second direction is 0.2λ-1λ; the minimum distance Gap10 between each of the secondary weighted portions 54 and the bus bar to which each of the secondary weighted portions 54 is close in the first direction is 0.005λ-0.03λ, the minimum distance Gap11 between each of the secondary weighted portions 54 and the edge of the electrode strip where each of the secondary weighted portions 54 is located parallel to the second direction is 0.005λ-0.03λ, and each The minimum distance Gap12 between the secondary weighted parts 54 and the weighted connecting strips close to each of the secondary weighted parts 54 in the first direction is 0.005λ-0.03λ; the minimum distance Gap3 between each of the primary weighted parts 51 and the edge of the electrode strip where each of the primary weighted parts 51 is located parallel to the first direction is 0.005λ-0.03λ, and the minimum distance Gap4 between each of the primary weighted parts 51 and the edge of the electrode strip where each of the primary weighted parts 51 is located parallel to the second direction is 0.005λ-0.03λ;

[0148] The lengths CB of the first weighted connecting bar 31 and the second weighted connecting bar 32 in parallel to the second direction are both 0.02λ-0.25λ, the minimum distance Gap2 between each free end 24 and the weighted connecting bar closest to it in parallel to the second direction is 0.02λ-0.4λ, and the minimum distance Gap1 between each free end 24 and the bus bar closest to it in parallel to the second direction is 1λ-2λ;

[0149] When the load structure is a primary weighting part 51, the projection of each primary weighting part 51 on the plane where the interdigital transducer structure is located is located inside the projection of the electrode strip where each primary weighting part 51 is located on the plane where the interdigital transducer structure is located, the length of the electrode strip where the primary weighting part 51 is located in the first direction is greater than the length of the primary weighting part 51 in the first direction, and the length Piston of each primary weighting part 51 in parallel to the second direction is 0.5λ-1λ;

[0150] λ is the wavelength of the surface acoustic wave propagating in the interdigital transducer structure.

[0151] This embodiment can also be combined with any one or more combinations of any features in other embodiments to obtain a new structure, and the obtained structures are all within the scope of protection of the present invention.

[0152] Embodiment 5:

[0153] This embodiment provides an interdigital transducer structure, which has the same other features as the interdigital transducer structure in Embodiment 1, Embodiment 3 or Embodiment 4, except that:

[0154] The load structure is a weighted horizontal bar 55, which is parallel to the first direction. One weighted horizontal bar 55 is arranged on the surface of the free end 24 of the first electrode strip 21 in the second direction, and the other weighted horizontal bar 55 is arranged on the surface of the free end 24 of the second electrode strip 22 in the second direction.

[0155] Specifically, the surface where the weighted horizontal strip 55 is located includes the upper surface and / or the lower surface, or an additional layer is provided between the surface and the structure, and the additional layer can be a temperature compensation layer and / or a passivation layer, etc., all of which belong to the protection scope of the present invention. Figure 19-Figure 22 FIG. 4 is a schematic diagram showing the structure of the weighted horizontal strip 55 on the upper surface of the electrode strip.

[0156] The present invention improves the acoustic wave propagation property between the monopole region A and the interdigital region B by arranging the weighted horizontal strip 55 in the interdigital region B, thereby optimizing the suppression effect on the transverse mode.

[0157] In one embodiment, a distance Gap8 between the weighted horizontal bar 55 and the edge of the free end 24 close to it in the second direction is 0.005λ-0.03λ, and a length S of the weighted horizontal bar 55 in the second direction is 0.5λ-1λ.

[0158] In one embodiment, the weighted horizontal strip 55 is made of silicon dioxide.

[0159] In one embodiment, Fig.19 As shown, the projections of the first weighted connecting strips 31 in the second direction overlap, and the projections of the second weighted connecting strips 32 in the second direction overlap.

[0160] In one embodiment, Fig. 20 The figure shows an enlarged view of the interdigital transducer structure with the weighted horizontal bar 55, wherein the length CB of the first weighted connecting bar 31 and the second weighted connecting bar 32 in parallel to the second direction is 0.02λ-0.25λ, the minimum distance Gap2 between each free end 24 and the weighted connecting bar closest to it in parallel to the second direction is 0.02λ-0.4λ, and the minimum distance Gap1 between each free end 24 and the bus bar closest to it in parallel to the second direction is 1λ-2λ; the distance Gap8 between the weighted horizontal bar 55 and the edge of the free end 24 to which it is close in the second direction is 0.005λ-0.03λ, and the length S of the weighted horizontal bar 55 in the second direction is 0.5λ-1λ;

[0161] λ is the wavelength of the surface acoustic wave propagating in the interdigital transducer structure.

[0162] In one embodiment, Fig.21 As shown, the weighted connecting strips include a first weighted connecting strip 31 and a second weighted connecting strip 32. The two adjacent first weighted connecting strips 31 along the first direction are staggered in the second direction so that the projections of the two adjacent first weighted connecting strips 31 in the first direction do not overlap; the two adjacent second weighted connecting strips 32 along the first direction are staggered in the second direction so that the projections of the two adjacent second weighted connecting strips 32 in the first direction do not overlap.

[0163] The present invention further improves the influence of the weighted connecting strips on the acoustic wave propagation properties between the monopole region A and the interdigital region B by coordinating the structure of the staggered distribution of the weighted connecting strips, and further optimizes the suppression effect on the transverse mode.

[0164] In one embodiment, Fig. 22The diagram shows an enlarged view of the interdigital transducer structure of the staggered weighted connecting strips, wherein the distance Gap8 between the weighted horizontal strip 55 and the edge of the free end 24 to which it is close in the second direction is 0.005λ-0.03λ, and the length S of the weighted horizontal strip 55 in the second direction is 0.5λ-1λ; the minimum distance Gap1 between each free end 24 and the closest bus bar in parallel to the second direction is 1λ-2λ; the two first weighted connecting strips 31 adjacent to each other in the first direction and the corresponding second electrode strips 22 in the second direction are The minimum distances Gap5 and Gap6 are 0.02λ-0.4λ and 0.1λ-0.6λ respectively, the minimum distances Gap5 and Gap6 between two adjacent second weighted connecting strips 32 along the first direction and their corresponding first electrode strips 21 in the second direction are 0.02λ-0.4λ and 0.1λ-0.6λ respectively, the lengths CB1 and CB2 of the first weighted connecting strip 31 and the second weighted connecting strip 32 parallel to the second direction are both 0.02λ-0.25λ; λ is the wavelength of the surface acoustic wave propagating in the interdigital transducer structure.

[0165] In one embodiment, projections of two spaced-apart first weighted connecting strips 31 in the first direction overlap, and / or projections of two spaced-apart second weighted connecting strips 32 in the first direction overlap.

[0166] In one embodiment, projections of two spaced-apart first weighted connecting strips 31 in the first direction do not overlap, and / or projections of two spaced-apart second weighted connecting strips 32 in the first direction do not overlap.

[0167] This embodiment can also be combined with any one or more combinations of any features in other embodiments to obtain a new structure, and the obtained structures are all within the scope of protection of the present invention.

[0168] Embodiment 6:

[0169] This embodiment provides an IDT structure, which has the same other features as the IDT structure in Embodiment 5, except that:

[0170] In the interdigital area B, an auxiliary weighting portion 56 is provided on the first electrode strip 21 and the second electrode strip 22 near the two weighting horizontal strips 55 ; the auxiliary weighting portion 56 is provided between the two weighting horizontal strips 55 , or the auxiliary weighting portion 56 is not provided between the two weighting horizontal strips 55 .

[0171] In one embodiment, Fig.23As shown, the weighted connecting strips include a first weighted connecting strip 31 and a second weighted connecting strip 32 , the projections of the first weighted connecting strip 31 in the first direction overlap, and the projections of the second weighted connecting strip 32 in the first direction overlap.

[0172] In one embodiment, Fig.24 The figure shows an enlarged view of the interdigital transducer structure with the auxiliary weighted portion 56, wherein the minimum distance Gap9 between the auxiliary weighted portion 56 and the weighted horizontal bar 55 adjacent to it in the second direction is 0.1λ-0.5λ, the minimum distance Gap3 between the free end of the weighted horizontal bar 55 and the edge of the electrode strip adjacent to it parallel to the first direction is 0.005λ-0.03λ, and the minimum distance Gap4 between each of the auxiliary weighted portions 56 and the edge of the electrode strip where each of the auxiliary weighted portions 56 is located parallel to the second direction is 0.005λ-0.03λ; the weighted horizontal bar 55 is located at the The length S in the second direction is 0.2λ-1λ, and the length Piston4 of the auxiliary weighted portion 56 in the second direction is 0.2λ-1λ; the lengths CB of the first weighted connecting bar 31 and the second weighted connecting bar 32 in parallel to the second direction are both 0.02λ-0.25λ, and the minimum distance Gap2 between each free end 24 and the weighted connecting bar closest to it in parallel to the second direction is 0.02λ-0.4λ, and the minimum distance Gap1 between each free end 24 and the bus bar closest to it in parallel to the second direction is 1λ-2λ;

[0173] λ is the wavelength of the surface acoustic wave propagating in the interdigital transducer structure.

[0174] In one embodiment, the auxiliary weight portion 56 is disposed between two of the weighted horizontal bars 55, or the auxiliary weight portion 56 is not disposed between two of the weighted horizontal bars 55, that is, the order of the auxiliary weight portion 56 and the adjacent weighted horizontal bars 55 in the second direction can be interchanged.

[0175] In one embodiment, Fig.25 As shown, the weighted connecting strips include a first weighted connecting strip 31 and a second weighted connecting strip 32. The two adjacent first weighted connecting strips 31 along the first direction are staggered in the second direction so that the projections of the two adjacent first weighted connecting strips 31 in the first direction do not overlap; the two adjacent second weighted connecting strips 32 along the first direction are staggered in the second direction so that the projections of the two adjacent second weighted connecting strips 32 in the first direction do not overlap.

[0176] The present invention further improves the influence of the weighted connecting strips on the acoustic wave propagation properties between the monopole region A and the interdigital region B by coordinating the structure of the staggered distribution of the weighted connecting strips, and further optimizes the suppression effect on the transverse mode.

[0177] In one embodiment, Fig.26 The figure shows an enlarged view of the interdigital transducer structure of the staggered distribution of the weighted connecting strips, wherein the minimum distance Gap9 between the auxiliary weighted portion 56 and the weighted horizontal bar 55 adjacent to it in the second direction is 0.1λ-0.5λ, the minimum distance Gap3 between the free end of the weighted horizontal bar 55 and the edge of the electrode strip adjacent to it in parallel with the first direction is 0.005λ-0.03λ, the minimum distance Gap4 between each of the auxiliary weighted portions 56 and the edge of the electrode strip where each of the auxiliary weighted portions 56 is located in parallel with the second direction is 0.005λ-0.03λ; the length S of the weighted horizontal bar 55 in the second direction is 0.2λ-1λ, the length Piston4 of the auxiliary weighted portion 56 in the second direction is 0.2λ-1λ; each of the free ends 24 and the electrode strip closest to it is parallel to the first direction. The minimum distance Gap1 of the bus bar parallel to the second direction is 1λ-2λ; the minimum distances Gap5 and Gap6 between two adjacent first weighted connecting bars 31 and their corresponding second electrode bars 22 along the first direction are 0.02λ-0.4λ and 0.1λ-0.6λ respectively, the minimum distances Gap5 and Gap6 between two adjacent second weighted connecting bars 32 and their corresponding first electrode bars 21 along the first direction are 0.02λ-0.4λ and 0.1λ-0.6λ respectively, the lengths CB1 and CB2 of the first weighted connecting bar 31 and the second weighted connecting bar 32 parallel to the second direction are both 0.02λ-0.25λ; λ is the wavelength of the surface acoustic wave propagating in the interdigital transducer structure.

[0178] In one embodiment, projections of two spaced-apart first weighted connecting strips 31 in the first direction overlap, and / or projections of two spaced-apart second weighted connecting strips 32 in the first direction overlap.

[0179] In one embodiment, projections of two spaced-apart first weighted connecting strips 31 in the first direction do not overlap, and / or projections of two spaced-apart second weighted connecting strips 32 in the first direction do not overlap.

[0180] This embodiment can also be combined with any one or more combinations of any features in other embodiments to obtain a new structure, and the obtained structures are all within the scope of protection of the present invention.

[0181] Embodiment 7:

[0182] This embodiment provides a filter structure, which includes any one of the interdigital transducer structures in Embodiments 1-6.

[0183] In one embodiment, Fig. 27 As shown, the filter structure is a topological structure including a duplexer composed of 9 interdigital transducer structures F8-F16, parallel resonators P1-P6, series resonators S1-S7, and inductors L3-L6.

[0184] Specifically, the interdigital transducer structure is usually applied to filtering at a receiving end frequency band in a filter structure.

[0185] In one embodiment, the filter structure further includes two reflection grating arrays 40, which are respectively arranged on both sides of the interdigital transducer structure along the first direction, each of the reflection grating arrays 40 is composed of at least two metal reflection strips 42 and two auxiliary bus bars 41, the metal reflection strips 42 are parallel to the second direction and arranged along the first direction, and each of the metal reflection strips 42 is respectively in contact with the two auxiliary bus bars 41 at both ends in the second direction, and a reflection grating load structure is arranged on the reflection grating array 40 at a position where the projection of the load structure of the interdigital transducer structure in the first direction coincides.

[0186] The present invention improves the reflection efficiency of the filter by providing the reflection grid array 40.

[0187] In one embodiment, Figure 2 As shown, when the load structure of the interdigital transducer structure is the primary weighting part 51, the reflective grating load structure is also the primary weighting part 51, and the primary weighting part 51 of the reflective grating array 40 is located on the metal reflective strip 42 at a position corresponding to the primary weighting part 51 of the interdigital transducer structure in the first direction.

[0188] The present invention further improves the reflection efficiency of the filter by arranging a primary emphasis portion 51 corresponding to the interdigital transducer structure at a corresponding position on the reflection grid array 40 .

[0189] This embodiment can also be combined with any one or more combinations of any features in other embodiments to obtain a new structure, and the obtained structures are all within the scope of protection of the present invention.

[0190] Embodiment 8:

[0191] This embodiment provides a filter structure, which has the same other features as the filter structure in Embodiment 7, except that:

[0192] like Fig.11As shown, when the primary weighting portion 51 of the interdigital transducer structure is composed of at least two sub-weighting portions 52, each primary weighting portion 51 on the metal reflective strip 42 is also composed of at least two sub-weighting portions 52 arranged along the second direction, and the sub-weighting portions 52 of the reflective grating array 40 are located at positions on the metal reflective strip 42 corresponding to the sub-weighting portions 52 of the interdigital transducer structure in the first direction.

[0193] In the present invention, at least two sub-emphasis portions 52 corresponding to the interdigital transducing structures are arranged at corresponding positions on the reflection grid array 40 to further improve the reflection efficiency of the filter.

[0194] This embodiment can also be combined with any one or more combinations of any features in other embodiments to obtain a new structure, and the obtained structures are all within the scope of protection of the present invention.

[0195] Embodiment 9:

[0196] This embodiment provides a filter structure, which has the same other features as the filter structure in Embodiment 7, except that:

[0197] like Fig.19 As shown, when the load structure of the interdigital transducer structure is a weighted bar 55, the reflective grating load structure is also a weighted bar 55, and the weighted bar 55 of the reflective grating array 40 is connected to the weighted bar 55 of the interdigital transducer structure and their projections in the first direction overlap.

[0198] The present invention further improves the reflection efficiency of the filter by arranging weighted horizontal bars 55 corresponding to the interdigital transducing structure at corresponding positions on the reflection grid array 40 .

[0199] This embodiment can also be combined with any one or more combinations of any features in other embodiments to obtain a new structure, and the obtained structures are all within the scope of protection of the present invention.

[0200] Embodiment 10:

[0201] This embodiment provides a filter structure, which has the same other features as the filter structure in Embodiment 9, except that:

[0202] like Fig.23 As shown, when the interdigital transducer structure is provided with an auxiliary weighting portion 56, the reflection grating array 40 is also provided with an auxiliary weighting portion 56, and the auxiliary weighting portion 56 of the reflection grating array 40 is located at a position on the metal reflection strip 42 corresponding to the auxiliary weighting portion 56 of the interdigital transducer structure in the first direction.

[0203] The present invention further improves the reflection efficiency of the filter by arranging the auxiliary weighting part 56 corresponding to the interdigital transducing structure at the corresponding position on the reflection grid array 40 .

[0204] This embodiment can also be combined with any one or more combinations of any features in other embodiments to obtain a new structure, and the obtained structures are all within the scope of protection of the present invention.

[0205] Embodiment 11:

[0206] This embodiment provides an electronic device, which includes the filter structure described in any one of Embodiments 7-10.

[0207] In summary, the interdigital transducer structure, filter structure and electronic device of the present invention can suppress the transverse mode in the RF filter band and reduce the loss by setting a weighted connecting strip in the monopole area and setting a load structure in the interdigital area; at the same time, the transverse mode can be further suppressed by staggered setting of the weighted connecting strips; in addition, the suppression effect on the transverse mode can be further improved by coordinating the setting of the weighted connecting column, the sub-weighted part and the auxiliary weighted part; finally, the load structure can be used as a weighted horizontal strip or a primary weighted part to further improve the suppression effect on the transverse mode.

[0208] Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0209] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. An interdigital transducer structure, characterized in that: The interdigital transducer structure comprises: a bus bar, an electrode bar, a weighted connecting bar and a load structure; The bus bar includes a first bus bar and a second bus bar arranged in parallel, and the electrode bar includes a first electrode bar and a second electrode bar; a plurality of the first electrode bars are arranged on the first bus bar, a plurality of the second electrode bars are arranged on the second bus bar, and the plurality of the first electrode bars and the plurality of the second electrode bars are arranged relatively spaced apart in a middle area between the first bus bar and the second bus bar; the end of the electrode bar connected to the bus bar is a connecting end, and the end of the electrode bar away from the connecting end is a free end; The direction parallel to the first bus bar is the first direction, the direction perpendicular to the first direction and parallel to the plane where the interdigital transducer structure is located is the second direction, and the third direction is perpendicular to both the first direction and the second direction; the intermediate region includes an interdigital region and a unipolar region that does not belong to the interdigital region, and the interdigital region is a region formed between the edge of the free end of the first electrode strip and the edge of the free end of the second electrode strip; The weighted connecting bar is located in the monopolar region, and the weighted connecting bar is located between the free end of the first electrode bar and the second bus bar, and / or between the free end of the second electrode bar and the first bus bar; There is a preset distance in the second direction between the projection of the load structure on the electrode strip and the edge of the free end of the electrode strip.

2. The interdigital transducer structure according to claim 1, characterized in that: The load structure is a primary weighting part, which is respectively located on the surface of the free end of the first electrode strip, and / or the surface of the second electrode strip at a position corresponding to the free end of the first electrode strip in the first direction, and / or the surface of the free end of the second electrode strip, and / or the surface of the first electrode strip at a position corresponding to the free end of the second electrode strip in the first direction.

3. The interdigital transducer structure according to claim 2, characterized in that: Each of the primary weight portions includes at least two sub-weight portions arranged along the second direction.

4. The interdigital transducer structure according to claim 2, characterized in that: The weighted connecting bar includes a first weighted connecting bar and a second weighted connecting bar, the second weighted connecting bar is connected to the second bus bar at a position corresponding to the first electrode bar along the second direction through a weighted connecting column, and the first weighted connecting bar is connected to the first bus bar at a position corresponding to the second electrode bar along the second direction through a weighted connecting column.

5. The interdigital transducer structure according to claim 4, characterized in that: A secondary weight portion is arranged on each of the weighted connecting columns.

6. The interdigital transducer structure according to claim 1, characterized in that: The load structure is a weighted horizontal bar, which is parallel to the first direction. One of the weighted horizontal bars is arranged on the surface of the free end of the first electrode bar in the second direction, and the other weighted horizontal bar is arranged on the surface of the free end of the second electrode bar in the second direction.

7. The interdigital transducer structure according to claim 6, characterized in that: In the interdigital area, an auxiliary weighting portion is provided on the first electrode strip and the second electrode strip near the two weighting horizontal strips; the auxiliary weighting portion is provided between the two weighting horizontal strips, or the auxiliary weighting portion is not provided between the two weighting horizontal strips.

8. The interdigital transducer structure according to any one of claims 1 to 7, characterized in that: The weighted connecting strips include a first weighted connecting strip and a second weighted connecting strip, the projections of the first weighted connecting strip in the first direction overlap, and the projections of the second weighted connecting strip in the first direction overlap; The lengths of the first weighted connecting strip and the second weighted connecting strip in parallel to the second direction are both 0.02λ-0.25λ, the minimum distance between each free end and the weighted connecting strip closest to it in parallel to the second direction is 0.02λ-0.4λ, and the minimum distance between each free end and the bus bar closest to it in parallel to the second direction is 1λ-2λ; When the load structure is a primary weighting part, the projection of each primary weighting part on the plane where the interdigital transducer structure is located is located inside the projection of the electrode strip where each primary weighting part is located on the plane where the interdigital transducer structure is located, the length of the electrode strip where the primary weighting part is located in the first direction is greater than the length of the primary weighting part in the first direction, and the length of each primary weighting part parallel to the second direction is 0.5λ-1λ; λ is the wavelength of the surface acoustic wave propagating in the interdigital transducer structure.

9. The interdigital transducer structure according to any one of claims 1 to 7, characterized in that: The weighted connecting strips include a first weighted connecting strip and a second weighted connecting strip, and two adjacent first weighted connecting strips along the first direction are staggered in the second direction so that the projections of the two adjacent first weighted connecting strips in the first direction do not overlap; Two adjacent second weighted connecting strips along the first direction are staggeredly distributed in the second direction, so that the projections of the two adjacent second weighted connecting strips in the first direction do not overlap.

10. The interdigital transducer structure according to claim 9, characterized in that: The minimum distances between two adjacent first weighted connecting strips along the first direction and their corresponding second electrode strips in the second direction are 0.02λ-0.4λ and 0.1λ-0.6λ respectively, the minimum distances between two adjacent second weighted connecting strips along the first direction and their corresponding first electrode strips in the second direction are 0.02λ-0.4λ and 0.1λ-0.6λ respectively, the lengths of the first weighted connecting strip and the second weighted connecting strip parallel to the second direction are both 0.02λ-0.25λ; λ is the wavelength of surface acoustic waves propagating in the interdigital transducer structure.

11. A filter structure, comprising the interdigital transducer structure according to any one of claims 1 to 10.

12. The filter structure according to claim 11, characterized in that The filter structure also includes two reflection grating arrays, which are respectively arranged on both sides of the interdigital transducer structure along the first direction, each of the reflection grating arrays is composed of at least two metal reflection bars and two auxiliary bus bars, the metal reflection bars are parallel to the second direction and arranged along the first direction, and each of the metal reflection bars is respectively in contact with the two auxiliary bus bars at two ends in the second direction, and a reflection grating load structure is arranged on the reflection grating array at a position where the projection of the load structure of the interdigital transducer structure in the first direction coincides.

13. The filter structure according to claim 12, characterized in that: When the load structure of the interdigital transducer structure is a primary weighting part, the reflective grating load structure is also a primary weighting part, and the primary weighting part of the reflective grating array is located at a position on the metal reflective strip corresponding to the primary weighting part of the interdigital transducer structure in the first direction.

14. The filter structure according to claim 13, characterized in that: When the primary weighting portion of the interdigital transduction structure is at least two sub-weighting portions, each primary weighting portion on the metal reflection strip is also at least two sub-weighting portions arranged along the second direction, and the sub-weighting portions of the reflection grating array are located at positions on the metal reflection strip corresponding to the sub-weighting portions of the interdigital transduction structure in the first direction.

15. The filter structure according to claim 12, characterized in that: When the load structure of the IDT structure is a weighted bar, the reflective grating load structure is also a weighted bar. The weighted bar of the reflective grating array is connected to the weighted bar of the IDT structure and their projections in the first direction overlap.

16. The filter structure according to claim 15, characterized in that When the interdigital transducing structure is provided with an auxiliary weighting portion, the reflective grating array is also provided with an auxiliary weighting portion, and the auxiliary weighting portion of the reflective grating array is located at a position on the metal reflective strip corresponding to the auxiliary weighting portion of the interdigital transducing structure in the first direction.

17. An electronic device, comprising the filter structure according to any one of claims 11 to 16.

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