An interdigital transducer structure, a filter structure and an electronic device

Abstract

The present invention provides an interdigital transducer structure, a filter structure and an electronic device. The interdigital transducer structure includes a plurality of first electrode bars and second electrode bars which are arranged at intervals between two bus bars; a weighted connection bar is located in a monopole region, and there is a preset distance in a second direction between the projection of a load structure on the electrode bar and the edge of the free end of the electrode bar. By arranging a weighted connection bar in the monopole region and a load structure in the interdigital region, the present invention suppresses the transverse mode in the band of a radio frequency filter and reduces the loss; at the same time, by arranging the weighted connection bars in a staggered manner, the transverse mode is further suppressed; in addition, with the arrangement of a weighted connection column, a sub-weighted part and an accessory weighted part, the suppression effect on the transverse mode is further improved; finally, by using the load structure as a weighted cross bar or a primary weighted part, the suppression effect on the transverse mode is further improved.

Description

Technical Field

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

[0002] With the development of communication technology from 2G to 5G, the number of communication frequency bands has gradually increased (rising from 4 frequency bands in 2G to more than 50 frequency bands in 5G). In order to improve the compatibility of smart phones with different communication systems, the demand for filters in 5G smart phones will increase significantly, driving the large-scale growth of the filter market. The radio frequency filters currently widely used in wireless communication terminals are surface acoustic wave (SAW) filters, which are responsible for filtering the radio frequency signals in the receiving and transmitting channels and outputting the signals with specific frequencies among the input multiple radio frequency signals. At the same time, with the continuous development of mobile communication technology and the development of radio frequency front-end modularization, the demand for filters in high-end applications tends to be more complex, high-end and miniaturized.

[0003] Ordinary SAW (Surface Acoustic Wave) filters have been widely used in radio frequency filters at present. However, for high-end devices, the performance deterioration caused by the transverse mode in the ordinary SAW structure can no longer meet the requirements of radio frequency front-end chips. As a conventional design method, the structure of ordinary SAW is as Figure 1 shown, including only an ordinary bus bar 61 and interdigital electrode bars 62. As a resonator and a radio frequency filter, ordinary SAW will generate a strong transverse mode, which cannot meet the low insertion loss requirement 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 of the technical background is only for the convenience of clearly and completely explaining the technical solutions of the present application and facilitating the understanding of those skilled in the art. It cannot be considered that the above technical solutions are well-known to those skilled in the art just because these solutions are described in the background art part of the present application. Summary of the Invention

[0006] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide an interdigital transducer structure, a filter structure and an electronic device, which are used to solve the problems of large insertion loss and poor performance caused by the transverse mode of surface acoustic wave filters in radio frequency applications in the prior art.

[0007] To achieve the above purpose, the present invention provides an interdigital transducer structure, which includes: a bus bar, electrode bars, a weighted connection bar and a load structure;

[0008] The bus bar includes a first bus bar and a second bus bar arranged in parallel. The electrode bars include a first electrode bar and a second electrode bar. A plurality of the first electrode bars are provided on the first bus bar, and a plurality of the second electrode bars are provided on the second bus bar. The plurality of first electrode bars and the plurality of second electrode bars are relatively spaced apart and arranged in the intermediate region between the first bus bar and the second bus bar. The end of the electrode bar connected to the bus bar is the connection end, and the end of the electrode bar away from the connection end is the free end.

[0009] 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 at the same time.

[0010] The intermediate region includes an interdigital region and a monopole region that does not belong to the interdigital region. The interdigital region is the region formed between the edges of the free ends of the first electrode bars and the edges of the free ends of the second electrode bars.

[0011] The weighted connection bar is located in the monopole region. The weighted connection 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 bar and the edge of the free end of the electrode bar.

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

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

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

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

[0017] Optionally, the load structure is a weighted crossbar, the weighted crossbar is parallel to the first direction, one weighted crossbar is disposed on the surface close to the free end of the first electrode bar in the second direction, and the other weighted crossbar is disposed on the surface close to the free end of the second electrode bar in the second direction.

[0018] Optionally, in the interdigital region, auxiliary weighted portions are provided at positions on the first electrode bar and the second electrode bar close to the two weighted crossbars; the auxiliary weighted portions are disposed between the two weighted crossbars, or the auxiliary weighted portions are not disposed between the two weighted crossbars.

[0019] Optionally, the weighted connection bars include a first weighted connection bar and a second weighted connection bar, and the projections of the first weighted connection bar in the first direction coincide, and the projections of the second weighted connection bar in the first direction coincide;

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

[0021] When the load structure is a primary weighted portion, the projections of the primary weighted portions on the plane where the interdigital transducer structure is located are located inside the projections of the electrode bars where the primary weighted portions are located on the plane where the interdigital transducer structure is located, the length of the electrode bar where the primary weighted portion is located in the first direction is greater than the length of the primary weighted portion in the first direction, and the lengths of the primary weighted portions in the direction parallel to the second direction are 0.5λ - 1λ; λ is the wavelength of the surface acoustic wave propagating in the interdigital transducer structure.

[0022] Optionally, the weighted connection bars include a first weighted connection bar and a second weighted connection bar, and two adjacent first weighted connection bars along the first direction are staggered in the second direction, so that the projections of the two adjacent first weighted connection bars in the first direction do not coincide; two adjacent second weighted connection bars along the first direction are staggered in the second direction, so that the projections of the two adjacent second weighted connection bars in the first direction do not coincide.

[0023] Optionally, the minimum distances between two adjacent first weighted connection bars in the first direction and their corresponding second electrode bars in the second direction are 0.02λ - 0.4λ and 0.1λ - 0.6λ respectively, and the minimum distances between two adjacent second weighted connection bars in the first direction and their corresponding first electrode bars in the second direction are 0.02λ - 0.4λ and 0.1λ - 0.6λ respectively. The lengths of the first weighted connection bar and the second weighted connection bar in a direction 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.

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

[0025] Optionally, the filter structure further includes two reflection grating arrays, which are respectively arranged on both sides of the interdigital transducer structure along the first direction. Each reflection grating array is composed of at least two metal reflection bars and two sub-bus bars. The metal reflection bars are parallel to the second direction and arranged along the first direction. Both ends of each metal reflection bar in the second direction are respectively in contact with the two sub-bus bars. A reflection grating load structure is arranged at a position on the reflection grating array where the projection of the load structure of the interdigital transducer structure coincides with it in the first direction.

[0026] Optionally, when the load structure of the interdigital transducer structure is a primary weighted part, the reflection grating load structure is also a primary weighted part, and the primary weighted part of the reflection grating array is located at a position on the metal reflection bar corresponding to the primary weighted part of the interdigital transducer structure in the first direction.

[0027] Optionally, when the primary weighted part of the interdigital transducer structure is at least two sub-weighted parts, each primary weighted part on the metal reflection bar is also at least two sub-weighted parts arranged along the second direction, and the sub-weighted part of the reflection grating array is located at a position on the metal reflection bar corresponding to the sub-weighted part of the interdigital transducer structure in the first direction.

[0028] When the load structure of the interdigital transducer structure is a weighted cross bar, the reflection grating load structure is also a weighted cross bar, and the weighted cross bar of the reflection grating array is connected to the weighted cross bar of the interdigital transducer structure and their projections coincide in the first direction.

[0029] When the interdigital transducer structure is provided with an accessory weighted part, the reflection grating array is also provided with an accessory weighted part, and the accessory weighted part of the reflection grating array is located at a position on the metal reflection bar corresponding to the accessory weighted part of the interdigital transducer structure in the first direction.

[0030] The present invention further provides an electronic device, which includes any one of the above-mentioned filter structures.

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

[0032] By arranging a weighted connection bar in the monopole region and a load structure in the interdigital region, the present invention suppresses the transverse mode in the band of the RF filter and reduces the loss;

[0033] Furthermore, for the load structure arranged in the interdigital region, there is a preset distance in the second direction between the projection on the electrode bar and the edge of the free end of the electrode bar, which can make the suppression effect of the transverse mode in the band of the RF filter better, the flatness in the passband better, further improve the characteristics of the RF filter, and enhance the performance of the RF filter.

[0034] By arranging the weighted connection bars in an interleaved manner, the present invention further suppresses the transverse mode;

[0035] In cooperation with the arrangement of the weighted connection posts, sub-weighted parts and auxiliary weighted parts, the present invention further improves the suppression effect on the transverse mode;

[0036] By using the load structure as a weighted cross bar or a primary weighted part, the present invention further improves the suppression effect on the transverse mode. Description of the Drawings

[0037] Figure 1 It shows a schematic structural diagram 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 weighted part in Embodiment 1 of the present invention.

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

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

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

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

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

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

[0045] Figure 9 It shows a schematic diagram of the structure of the interdigital transducer structure with staggered weighting connection bars set in an alternative example of Example 1 of the present invention.

[0046] Figure 10 It shows an enlarged schematic diagram of the structure of the interdigital transducer structure with staggered weighting connection bars set in an alternative example of Example 1 of the present invention.

[0047] Figure 11 It shows a schematic diagram of the structure of the interdigital transducer structure with a sub-weighting portion set in Example 2 of the present invention.

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

[0049] Figure 13 It shows a schematic diagram of the structure of the interdigital transducer structure with staggered weighting connection bars set in an alternative example of Example 2 of the present invention.

[0050] Figure 14 It shows an enlarged schematic diagram of the structure of the interdigital transducer structure with staggered weighting connection bars set in an alternative example of Example 2 of the present invention.

[0051] Figure 15 It shows a schematic diagram of the structure of the interdigital transducer structure with a weighting connection column set in Example 3 of the present invention.

[0052] Figure 16 It shows an enlarged schematic diagram of the structure of the interdigital transducer structure with a weighting connection column set in Example 3 of the present invention.

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

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

[0055] Figure 19 It shows a schematic diagram of the structure of the interdigital transducer structure with a weighting cross bar set in Example 5 of the present invention.

[0056] Figure 20It shows an enlarged structural schematic diagram of the interdigital transducer structure with a weighted crossbar set in Embodiment 5 of the present invention.

[0057] Figure 21 It shows a structural schematic diagram of the interdigital transducer structure with staggered weighted connection bars set in an alternative example of Embodiment 5 of the present invention.

[0058] Figure 22 It shows an enlarged structural schematic diagram of the interdigital transducer structure with staggered weighted connection bars set in an alternative example of Embodiment 5 of the present invention.

[0059] Figure 23 It shows a structural schematic diagram of the interdigital transducer structure with an attached weighted part set in Embodiment 6 of the present invention.

[0060] Figure 24 It shows an enlarged structural schematic diagram of the interdigital transducer structure with an attached weighted part set in Embodiment 6 of the present invention.

[0061] Figure 25 It shows a structural schematic diagram of the interdigital transducer structure with staggered weighted connection bars set in an alternative example of Embodiment 6 of the present invention.

[0062] Figure 26 It shows an enlarged structural schematic diagram of the interdigital transducer structure with staggered weighted connection bars set in an alternative example of Embodiment 6 of the present invention.

[0063] Figure 27 It shows a structural schematic diagram of the filter structure in an alternative example of Embodiment 7 of the present invention.

[0064] Element number description

[0065] A, monopole region; B, interdigital region;

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

[0067] 21, first electrode bar; 22, second electrode bar; 23, connection end; 24, free end;

[0068] 31, first weighted connection bar; 32, second weighted connection bar;

[0069] 40, reflection grating array; 41, sub-bus bar; 42, metal reflection bar;

[0070] 51, primary weighted part; 52, sub-weighted part; 53, weighted connection column; 54, secondary weighted part; 55, weighted crossbar; 56, attached weighted part;

[0071] 61, ordinary bus bar; 62, interdigital electrode bar. Detailed implementation manners

[0072] The following specific examples illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. All details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0073] When detailing the embodiments of the present invention, for ease of description, the schematic diagrams showing the device structure will be enlarged locally in a non-general proportion, and the schematic diagrams are only examples and should not limit the scope of protection of the present invention here. In addition, in actual production, three-dimensional spatial dimensions including length, width, and depth should be included.

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

[0075] In the context of the present application, the structure in which the first feature is "above" the 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 diagrams provided in the embodiments of the present invention only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The types, quantities, and proportions of the components in actual implementation may be arbitrarily changed, and the component layout type may also be more complex.

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

[0078] The numerical ranges in the context of the present invention include the boundary values of the ranges.

[0079] Embodiment 1:

[0080] As Figure 2As shown in the figure, this embodiment provides an interdigital transducer structure, which includes: a bus bar, electrode bars, a weighted connection bar, and a load structure;

[0081] The bus bar includes a first bus bar 11 and a second bus bar 12 arranged in parallel. The electrode bars include 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. The plurality of first electrode bars 21 and the plurality of second electrode bars 22 are arranged at intervals relative to each other 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 the connection end 23, and the end of the electrode bar away from the connection end 23 is the free end 24. The direction parallel to the first bus bar 11 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 at the same time;

[0082] The middle area includes an interdigital area B and a monopole area A that does not belong to the interdigital area B. The interdigital area B is the area formed between the edges of the free ends 24 of the first electrode bar 21 and the edges of the free ends 24 of the second electrode bar 22;

[0083] The weighted connection bar is located in the monopole area A, and the weighted connection 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 bar and the edge of the free end 24 of the electrode bar.

[0085] In the present invention, the load structure is arranged on the two end surfaces of the interdigital area B along the second direction. By adjusting the sound velocity of the monopole area A and the interdigital area B through the load structure, the maximum suppression of the lateral mode ripple is achieved. In addition, by setting a preset distance in the second direction between the projection of the load structure on the electrode bar and the edge of the free end 24, the cost required for the load structure is reduced, and at the same time, the short-circuit risk between the electrode bars caused by the existence of the load structure is avoided.

[0086] In addition, through experiments, in the comparative experiment, it is compared 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. When 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, compared with the case where there is no 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 arranged on the free end edge with a distance of zero from the edge), the lateral mode suppression effect in the passband of the RF filter can be better, the flatness in the passband is better, the characteristics of the RF filter can be further improved, and the performance of the RF filter can be enhanced. Specifically, Figure 2 The situation shown in Figure 2 is that the heavy connecting strip is provided both between the free end 24 of the first electrode strip 21 and the second bus bar 12 and between the free end 24 of the second electrode strip 22 and the first bus bar 11. The heavy connecting strip can also be provided only at one of them.

[0087] In one embodiment, the load structure can be on the upper surface and / or the lower surface of the electrode strip. For example, Figure 2 The figure shows a schematic structural diagram 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 strip.

[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. The primary weighting portion 51 is respectively located on the surface of the free end 24 of the first electrode strip 21, and / or on 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 on the surface of the free end 24 of the second electrode strip 22, and / or on 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, for example, Figure 2 The figure shows the situation where the primary weighting portion 51 is provided at all the above four positions. The primary weighting portion 51 can also be provided in any one or more arbitrary combinations of the above four positions, and can be adjusted and selected according to the cost and the performance requirements of the SAW, and all belong to the protection scope of the present invention.

[0092] Specifically, the primary weighting portion 51 includes an upper surface and / or a lower surface on the surface where it is located, or has a structure with an additional layer provided between the surface, and the additional layer can be a temperature compensation layer and / or a passivation layer, etc., all of which fall within the protection scope of the present invention. For example, Figure 2 The figure shows a schematic structural diagram of the primary weighting portion 51 presented on the upper surface of the electrode strip.

[0093] By providing the primary weighting portion 51 on the surface of the free end 24 in the interdigital region B and the corresponding surface of the electrode strip, the present invention further improves the acoustic wave propagation properties between the single-pole region A and the interdigital region B, thereby further suppressing the transverse mode of the surface acoustic wave filter, reducing losses, and improving the quality factor. For example, Figures 3 - 5 The figure shows a comparison of the resonance curves of a common SAW in the prior art and the resonance curves of the present invention with a weighting connection strip and a primary weighting portion 51 provided. Among them, the prior art is represented by a dashed 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 prove that the suppression effect of a single weighting connection strip and the primary weighting portion 51 on the transverse mode ripples is better than that of multiple weighting connection strips. For example, Figures 6 - 7 The figure shows a resonance curve graph comparing a common SAW (the dotted curve in the figure), a SAW with only the primary weighting portion 51 provided (the dashed curve in the figure), and a filter with the primary weighting portion 51 and a single weighting connection strip provided (the solid curve in the figure). It can be seen that the resonance curve of the filter with the primary weighting portion 51 and a single weighting connection strip provided is the smoothest, with the smallest burr phenomenon, smaller losses on both sides of the passband, and the highest quality factor obtained.

[0094] In one embodiment, for example, Figure 8 The figure shows an enlarged view of the above load structure as a primary weighting portion 51 interdigital transducer structure. The weighting connection strip includes a first weighting connection strip 31 and a second weighting connection strip 32. The projections of the first weighting connection strip 31 in the first direction coincide, and the projections of the second weighting connection strip 32 in the first direction coincide;

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

[0096] The projection of each of the primary weighting 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 weighting portions 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 length Piston of each of the primary weighting portions 51 in the direction parallel to the second direction is 0.5λ - 1λ;

[0097] The projection of each of the primary weighting 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 weighting portions 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 of the primary weighting portions 51 and the edge of the electrode strip where each of the primary weighting portions 51 is located and parallel to the first direction is 0.005λ - 0.03λ. The minimum distance Gap4 between each of the primary weighting portions 51 and the edge of the electrode strip where each of the primary weighting portions 51 is located and 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] By setting the width of the primary weighting portion 51 to be smaller than that of the electrode strip, the present invention further optimizes the acoustic wave propagation mode, reduces the lateral mode ripple, reduces the number of primary weighting portions 51 required while optimizing the SAW performance, and reduces the weight required for the filter, which is beneficial to the miniaturization and lightweight application of the SAW.

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

[0101] By setting the material of the primary weighting portion 51 to be a laminated structure of chromium / copper / chromium or chromium / silver / chromium, the present invention further optimizes the suppression of the lateral mode. In experiments on various materials, it is found that the laminated structures of chromium / copper / chromium and chromium / silver / chromium as the material of the primary weighting portion 51 can achieve the optimal performance, and at the same time improve the adhesion of the primary weighting portion 51 on the electrode strip.

[0102] In one embodiment, as Figure 9As shown, the weighted connection bars include a first weighted connection bar 31 and a second weighted connection bar 32. Two adjacent first weighted connection bars 31 along the first direction are staggered in the second direction, so that the projections of two adjacent first weighted connection bars 31 in the first direction do not overlap; two adjacent second weighted connection bars 32 along the first direction are staggered in the second direction, so that the projections of two adjacent second weighted connection bars 32 in the first direction do not overlap.

[0103] Through the structure in which the weighted connection bars are staggered, the present invention further improves the influence of the weighted connection bars on the acoustic wave propagation properties between the monopole region A and the interdigital region B, and further optimizes the suppression effect on the transverse mode.

[0104] In one embodiment, as Figure 10 shown is an enlarged view of the interdigital transducer structure with the above-mentioned staggered weighted connection bars 31. The minimum distances Gap5 and Gap6 between two adjacent first weighted connection bars 31 and their corresponding second electrode bars 22 in the second direction are 0.02λ - 0.4λ and 0.1λ - 0.6λ respectively. The minimum distances Gap5 and Gap6 between two adjacent second weighted connection bars 32 and their corresponding first electrode bars 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 connection bar 31 and the second weighted connection bar 32 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 parallel to the second direction is 1λ - 2λ;

[0105] The projections of the primary weighted portions 51 on the plane where the interdigital transducer structure is located are located inside the projections of the electrode bars where the primary weighted portions 51 are located on the plane where the interdigital transducer structure is located. The length of the electrode bar 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 length Piston of each primary weighted portion 51 parallel to the second direction is 0.5λ - 1λ;

[0106] The projection of each of the primary weighting 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 weighting portions 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 of the primary weighting portions 51 and the edge of the electrode strip where each of the primary weighting portions 51 is located and parallel to the first direction is 0.005λ - 0.03λ. The minimum distance Gap4 between each of the primary weighting portions 51 and the edge of the electrode strip where each of the primary weighting portions 51 is located and 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, the projections of two adjacent first weighting connection bars 31 in the first direction coincide, and / or the projections of two adjacent second weighting connection bars 32 in the first direction coincide.

[0108] In one embodiment, the projections of two adjacent first weighting connection bars 31 in the first direction do not coincide, and / or the projections of two adjacent second weighting connection bars 32 in the first direction do not coincide.

[0109] This embodiment can also be combined with any one or a combination of one or more of the 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 interdigital transducer structure, which is the same as the interdigital transducer structure in Embodiment 1 in other features, and the difference lies in:

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

[0113] The present invention further improves the acoustic wave propagation properties between the monopole region A and the interdigital region B by further improving the primary weighting portion 51 into a structure of two sub-weighting portions 52, and optimizes the suppression effect on the transverse mode.

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

[0115] In one embodiment, multiple sub-weighting portions 52 can also be arranged in different arrays, and the specific settings can be adjusted according to the actual structural needs and experimental effects.

[0116] In one embodiment, the weighted connection bars include a first weighted connection bar 31 and a second weighted connection bar 32. The projections of the first weighted connection bar 31 in the first direction coincide, and the projections of the second weighted connection bar 32 in the first direction coincide.

[0117] As Figure 12 Shown is an enlarged view of the above-mentioned interdigital transducer structure including at least two sub-weighted portions 52. The lengths CB of the first weighted connection bar 31 and the second weighted connection bar 32 in a direction parallel to the second direction are both 0.02λ - 0.25λ. The minimum distance Gap2 between each free end 24 and the weighted connection bar closest to it in a direction parallel to the second direction is 0.02λ - 0.4λ. The minimum distance Gap1 between each free end 24 and the bus bar closest to it in a direction 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 inside the projections of the electrode bars where the two sub-weighted portions 52 are located on the plane where the interdigital transducer structure is located. The lengths of the electrode bars where the two sub-weighted portions 52 are located in the first direction are 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-weighted portions 52 in the second direction are both 0.2λ - 1λ. The minimum distance Gap7 between the two sub-weighted portions 52 in the second direction is 0.1λ - 1λ. The minimum distance Gap3 between each sub-weighted portion 52 and the edge of the electrode bar where the sub-weighted portion 52 is located and parallel to the first direction is 0.005λ - 0.03λ. The minimum distance Gap4 between each sub-weighted portion 52 and the edge of the electrode bar where the sub-weighted portion 52 is located and 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, as Figure 13 Shown, the weighted connection bars include a first weighted connection bar 31 and a second weighted connection bar 32. Two adjacent first weighted connection bars 31 along the first direction are staggered in the second direction, so that the projections of the two adjacent first weighted connection bars 31 in the first direction do not coincide. Two adjacent second weighted connection bars 32 along the first direction are staggered in the second direction, so that the projections of the two adjacent second weighted connection bars 32 in the first direction do not coincide.

[0122] The present invention further improves the influence of the weighted connection bars on the acoustic wave propagation properties between the monopole region A and the interdigital region B by means of the structure in which the weighted connection bars are staggered, and further optimizes the suppression effect on the transverse mode.

[0123] In one embodiment, as Figure 14 shown is an enlarged view of the interdigital transducer structure in which the above-mentioned weighted connection bars 31 are staggered. The minimum distances Gap5 and Gap6 between two adjacent first weighted connection bars 31 and their corresponding second electrode bars 22 in the second direction 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 connection bars 32 and their corresponding first electrode bars 21 in the second direction along the first direction are 0.02λ - 0.4λ and 0.1λ - 0.6λ respectively. The lengths CB1 and CB2 of the first weighted connection bar 31 and the second weighted connection bar 32 in the direction 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 the direction 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 bars where the two sub-weighted portions 52 are located on the plane where the interdigital transducer structure is located. The length of the electrode bars 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-weighted portions 52 in the second direction are both 0.2λ - 1λ, and the minimum distance Gap7 between the two sub-weighted portions 52 in the second direction is 0.1λ - 1λ; the minimum distance Gap3 between each sub-weighted portion 52 and the edge of the electrode bar where each sub-weighted portion 52 is located parallel to the first direction is 0.005λ - 0.03λ, and the minimum distance Gap4 between each sub-weighted portion 52 and the edge of the electrode bar where each sub-weighted 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, the projections of two adjacent first weighted connection bars 31 in the first direction coincide, and / or the projections of two adjacent second weighted connection bars 32 in the first direction coincide.

[0128] In one embodiment, the projections of two spaced-apart first weighted connection bars 31 in the first direction do not overlap, and / or the projections of two spaced-apart second weighted connection bars 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 interdigital transducer structure, which is the same as the interdigital transducer structure in Embodiment 1 or Embodiment 2 in other features, and the difference lies in:

[0132] The weighted connection bars include a first weighted connection bar 31 and a second weighted connection bar 32. The second weighted connection 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 connection column 53, and the first weighted connection 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 connection 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 providing a weighted connection column 53 for connection between the adjacent weighted connection bar and the bus bar.

[0134] In one embodiment, as Figure 15 shown, the weighted connection bars include a first weighted connection bar 31 and a second weighted connection bar 32. The projection of the first weighted connection bar 31 in the first direction overlaps, and the projection of the second weighted connection bar 32 in the first direction overlaps.

[0135] In one embodiment, as Figure 16Shown is an enlarged view of the above-described weighted connection column 53 interdigital transducer structure. 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. 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 connection column 53 corresponding to the first electrode strip 21 in the first direction is the same as that of the first electrode strip 21. The length Pitch1 of the weighted connection column 53 corresponding to the second electrode strip 22 in the first direction is the same as that of the second electrode strip 22. λ is the wavelength of the surface acoustic wave propagating within the interdigital transducer structure.

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

[0137] When the load structure is the primary weighted portion 51, the projections of each of the primary weighted portions 51 on the plane where the interdigital transducer structure is located are within the projections of the electrode strips 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 length Piston of each of the primary weighted portions 51, parallel to the second direction, is 0.5λ - 1λ.

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

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

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

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

[0142] Example 4:

[0143] This embodiment provides an interdigital transducer structure. The interdigital transducer structure is the same as the interdigital transducer structure in Embodiment 3 in other features, and the difference lies in that:

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

[0145] The present invention further improves the acoustic wave propagation properties between the monopole region A and the interdigital region B by providing the secondary weighting portion 54 on the weighting connection post 53, and optimizes the suppression effect on the transverse mode.

[0146] In one embodiment, as Figure 17 shown, the weighting connection bars include a first weighting connection bar 31 and a second weighting connection bar 32. The projections of the first weighting connection bar 31 in the first direction coincide, and the projections of the second weighting connection bar 32 in the first direction coincide.

[0147] In one embodiment, as Figure 18 shown is an enlarged view of the interdigital transducer structure with the secondary weighting portion 54 provided as above. The length Piston3 of the secondary weighting portion 54 in the second direction is 0.2λ - 1λ; the minimum distance Gap10 between each of the secondary weighting portions 54 and the bus bar closest to it in the first direction is 0.005λ - 0.03λ, the minimum distance Gap11 between each of the secondary weighting portions 54 and the edge of the electrode bar where each of the secondary weighting portions 54 is located parallel to the second direction is 0.005λ - 0.03λ, and the minimum distance Gap12 between each of the secondary weighting portions 54 and the weighting connection bar closest to it in the first direction is 0.005λ - 0.03λ; the minimum distance Gap3 between each of the primary weighting portions 51 and the edge of the electrode bar where each of the primary weighting portions 51 is located parallel to the first direction is 0.005λ - 0.03λ, and the minimum distance Gap4 between each of the primary weighting portions 51 and the edge of the electrode bar where each of the primary weighting portions 51 is located parallel to the second direction is 0.005λ - 0.03λ;

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

[0149] When the load structure is the primary weighting portion 51, 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 length Piston of each primary weighting portion 51 in the direction 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 a combination of one or more arbitrary features in other embodiments to obtain a new structure, and the obtained structures are all within the protection scope 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 or Embodiment 3 or Embodiment 4, and the difference lies in:

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

[0155] Specifically, the surface where the weighting crossbar 55 is located includes an upper surface and / or a lower surface, or a structure with an additional layer is arranged between the surface and the surface. The additional layer can be a temperature compensation layer and / or a passivation layer, etc., and all belong to the protection scope of the present invention. For example, Figures 19 - 22 The schematic structural diagram shown in is the structure presented by the weighting crossbar 55 on the upper surface of the electrode strip.

[0156] The present invention improves the acoustic wave propagation property between the single-pole region A and the interdigital region B by arranging the weighting crossbar 55 in the interdigital region B, and optimizes the suppression effect on the transverse mode.

[0157] In one embodiment, the distance Gap8 between the weighting crossbar 55 and the edge of the free end 24 it approaches in the second direction is 0.005λ - 0.03λ, and the length S of the weighting crossbar 55 in the second direction is 0.5λ - 1λ.

[0158] In one embodiment, the material of the weighting crossbar 55 is silicon dioxide.

[0159] In one embodiment, for example,Figure 19 As shown, the projections of the first weighted connection bar 31 in the second direction coincide, and the projections of the second weighted connection bar 32 in the second direction coincide.

[0160] In one embodiment, as Figure 20 shown is an enlarged view of the interdigital transducer structure provided with the weighted cross bar 55. The lengths CB of the first weighted connection bar 31 and the second weighted connection bar 32 in a direction parallel to the second direction are both 0.02λ - 0.25λ. The minimum distance Gap2 between each free end 24 and the weighted connection bar closest to it in a direction parallel to the second direction is 0.02λ - 0.4λ. The minimum distance Gap1 between each free end 24 and the bus bar closest to it in a direction parallel to the second direction is 1λ - 2λ. The distance Gap8 between the weighted cross bar 55 and the edge of the free end 24 closest to it in the second direction is 0.005λ - 0.03λ. The length S of the weighted cross 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, as Figure 21 shown, the weighted connection bars include a first weighted connection bar 31 and a second weighted connection bar 32. Two adjacent first weighted connection bars 31 along the first direction are staggered in the second direction, so that the projections of two adjacent first weighted connection bars 31 in the first direction do not coincide. Two adjacent second weighted connection bars 32 along the first direction are staggered in the second direction, so that the projections of two adjacent second weighted connection bars 32 in the first direction do not coincide.

[0163] The present invention further improves the influence of the weighted connection bars on the acoustic wave propagation properties between the monopole region A and the interdigital region B by cooperating with the structure in which the weighted connection bars are staggered, and further optimizes the suppression effect on the transverse mode.

[0164] In one embodiment, as Figure 22Shown is an enlarged view of the interdigital transducer structure with the above-described staggered and distributed weighted connection bars. The distance Gap8 between the weighted cross bar 55 and the edge of the free end 24 it is close to in the second direction is 0.005λ - 0.03λ, and the length S of the weighted cross bar 55 in the second direction is 0.5λ - 1λ; the minimum distance Gap1 between each free end 24 and the bus bar closest to it in the direction parallel to the second direction is 1λ - 2λ; the minimum distances Gap5 and Gap6 between two adjacent first weighted connection bars 31 and their corresponding second electrode bars 22 in the second direction along the first direction are 0.02λ - 0.4λ and 0.1λ - 0.6λ respectively, and the minimum distances Gap5 and Gap6 between two adjacent second weighted connection bars 32 and their corresponding first electrode bars 21 in the second direction along the first direction are 0.02λ - 0.4λ and 0.1λ - 0.6λ respectively. The lengths CB1 and CB2 of the first weighted connection bar 31 and the second weighted connection bar 32 in the direction 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, the projections of two spaced-apart first weighted connection bars 31 in the first direction coincide, and / or the projections of two spaced-apart second weighted connection bars 32 in the first direction coincide.

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

[0167] This embodiment can also be combined with any one or a combination of one or more of the 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 interdigital transducer structure, which is the same as the interdigital transducer structure in Embodiment 5 in other features, and the difference lies in:

[0170] In the interdigital region B, auxiliary weighted portions 56 are provided at positions on the first electrode bar 21 and the second electrode bar 22 close to the two weighted cross bars 55; the auxiliary weighted portions 56 are provided between the two weighted cross bars 55, or the auxiliary weighted portions 56 are not provided between the two weighted cross bars 55.

[0171] In one embodiment, as Figure 23As shown, the weighted connection bars include a first weighted connection bar 31 and a second weighted connection bar 32. The projections of the first weighted connection bar 31 in the first direction coincide, and the projections of the second weighted connection bar 32 in the first direction coincide.

[0172] In one embodiment, as Figure 24 shown is an enlarged view of the interdigital transducer structure with the above-mentioned additional weighted portion 56 provided. The minimum distance Gap9 between the additional weighted portion 56 and the weighted cross bar 55 adjacent to it in the second direction is 0.1λ - 0.5λ. The minimum distance Gap3 between the weighted cross bar 55 and the edge of the free end of the electrode bar adjacent to it parallel to the first direction is 0.005λ - 0.03λ. The minimum distance Gap4 between each additional weighted portion 56 and the edge of the electrode bar where each additional weighted portion 56 is located parallel to the second direction is 0.005λ - 0.03λ. The length S of the weighted cross bar 55 in the second direction is 0.2λ - 1λ, and the length Piston4 of the additional weighted portion 56 in the second direction is 0.2λ - 1λ. The lengths CB of the first weighted connection bar 31 and the second weighted connection bar 32 in the direction parallel to the second direction are both 0.02λ - 0.25λ. The minimum distance Gap2 between each free end 24 and the weighted connection bar closest to it in the direction parallel to the second direction is 0.02λ - 0.4λ. The minimum distance Gap1 between each free end 24 and the bus bar closest to it in the direction 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 additional weighted portion 56 is provided between two of the weighted cross bars 55, or the additional weighted portion 56 is not provided between two of the weighted cross bars 55, that is, the order of the additional weighted portion 56 and the weighted cross bar 55 adjacent to it in the second direction can be swapped.

[0175] In one embodiment, as Figure 25 shown, the weighted connection bars include a first weighted connection bar 31 and a second weighted connection bar 32. Two adjacent first weighted connection bars 31 along the first direction are staggered in the second direction, so that the projections of two adjacent first weighted connection bars 31 in the first direction do not coincide. Two adjacent second weighted connection bars 32 along the first direction are staggered in the second direction, so that the projections of two adjacent second weighted connection bars 32 in the first direction do not coincide.

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

[0177] In one embodiment, as Figure 26 shown is an enlarged view of the interdigital transducer structure with the above-mentioned staggered distribution of the weighted connection bars. The minimum distance Gap9 between the auxiliary weighted part 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 weighted horizontal bar 55 and the free end of the electrode bar adjacent to it parallel to the edge in the first direction is 0.005λ - 0.03λ. The minimum distance Gap4 between each auxiliary weighted part 56 and the edge of the electrode bar where each auxiliary weighted part 56 is located parallel to 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 part 56 in the second direction is 0.2λ - 1λ. The minimum distance Gap1 between each free end 24 and the bus bar closest to it parallel to the second direction is 1λ - 2λ. The minimum distances Gap5 and Gap6 between two adjacent first weighted connection bars 31 and their corresponding second electrode bars 22 in the second direction 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 connection bars 32 and their corresponding first electrode bars 21 in the second direction along the first direction are 0.02λ - 0.4λ and 0.1λ - 0.6λ respectively. The lengths CB1 and CB2 of the first weighted connection bar 31 and the second weighted connection 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, the projections of two adjacent first weighted connection bars 31 in the first direction coincide, and / or the projections of two adjacent second weighted connection bars 32 in the first direction coincide.

[0179] In one embodiment, the projections of two adjacent first weighted connection bars 31 in the first direction do not coincide, and / or the projections of two adjacent second weighted connection bars 32 in the first direction do not coincide.

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

[0181] Embodiment 7:

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

[0183] In one embodiment, as Figure 27 shown, the filter structure is a topology structure including a duplexer composed of 9 of the 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 filter the receiving end frequency band in the filter structure.

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

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

[0187] In one embodiment, as Figure 2 shown, when the load structure of the interdigital transducer structure is the primary weighting part 51, the reflection grating load structure is also the primary weighting part 51. The primary weighting part 51 of the reflection grating array 40 is located at a position on the metal reflection bar 42 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 the primary weighting part 51 corresponding to the interdigital transducer structure at the corresponding position on the reflection grating array 40.

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

[0190] Embodiment 8:

[0191] This embodiment provides a filter structure. The other features of the filter structure are the same as those in Embodiment 7, and the difference is that:

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

[0193] In the present invention, by providing at least two sub-weight portions 52 corresponding to the interdigital transducer structure at corresponding positions on the reflection grating array 40, the reflection efficiency of the filter is further improved.

[0194] This embodiment can also be combined with any one or a combination of one or more arbitrary features in other embodiments to obtain a new structure, and the obtained structures are all within the protection scope 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, and the difference lies in:

[0197] As Figure 19 shown, when the load structure of the interdigital transducer structure is the weight bar 55, the reflection grating load structure is also the weight bar 55, and the weight bar 55 of the reflection grating array 40 is connected to the weight bar 55 of the interdigital transducer structure and their projections in the first direction coincide.

[0198] In the present invention, by providing a weight bar 55 corresponding to the interdigital transducer structure at a corresponding position on the reflection grating array 40, the reflection efficiency of the filter is further improved.

[0199] This embodiment can also be combined with any one or a combination of one or more arbitrary features in other embodiments to obtain a new structure, and the obtained structures are all within the protection scope 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, and the difference lies in:

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

[0203] In the present invention, an auxiliary weight portion 56 corresponding to the interdigital transducer structure is provided at a corresponding position on the reflection grating array 40, further improving the reflection efficiency of the filter.

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

[0205] Embodiment 11:

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

[0207] In summary, for the interdigital transducer structure, filter structure and electronic device of the present invention, the lateral mode in the RF filter band can be suppressed and the loss can be reduced by arranging a weighted connection bar in the monopole region and a load structure in the interdigital region; at the same time, the lateral mode can be further suppressed by arranging the weighted connection bars in a staggered manner; in addition, with the arrangement of the weighted connection column, sub - weight portion and auxiliary weight portion, the suppression effect on the lateral mode is further improved; finally, by using the load structure as the weighted cross bar or primary weight portion, the suppression effect on the lateral mode is further improved.

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

[0209] The above embodiments are only illustrative of the principles and effects of the present invention, and are not used to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. An interdigital transducer structure, characterized in that, The interdigital transducer structure includes: a bus bar, electrode bars, a weighted connection bar, and a load structure; The bus bar includes a first bus bar and a second bus bar arranged in parallel. The electrode bars include a first electrode bar and a second electrode bar. A plurality of the first electrode bars are provided on the first bus bar, and a plurality of the second electrode bars are provided on the second bus bar. The plurality of first electrode bars and the plurality of second electrode bars are arranged at intervals relative to each other in the intermediate region between the first bus bar and the second bus bar. The end of the electrode bar connected to the bus bar is the connection end, and the end of the electrode bar far from the connection end is the 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 at the same time. The intermediate region includes an interdigital region and a monopole region that does not belong to the interdigital region. The interdigital region is the region formed between the edges of the free ends of the first electrode bar and the edges of the free ends of the second electrode bar; The weighted connection bar is located in the monopole region. The weighted connection 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 bar and the edge of the free end of the electrode bar; The load structure is a primary weighted part. The primary weighted parts are respectively located on the surface of the free end of the first electrode bar, and / or on the surface of the second electrode bar at the position corresponding to the free end of the first electrode bar in the first direction, and / or on the surface of the free end of the second electrode bar, and / or on the surface of the first electrode bar at the position corresponding to the free end of the second electrode bar in the first direction. The projection of each primary weighted part on the plane where the interdigital transducer structure is located is located inside the projection of the electrode bar where each primary weighted part is located on the plane where the interdigital transducer structure is located. The length of the electrode bar where the primary weighted part is located in the first direction is greater than the length of the primary weighted part in the first direction. The minimum distance between each primary weighted part and the edge of the electrode bar where each primary weighted part is located and parallel to the first direction is 0.005λ - 0.03λ, where λ is the wavelength of the surface acoustic wave propagating in the interdigital transducer structure; Or, the load structure is a weighted cross bar. The weighted cross bar is parallel to the first direction. One weighted cross bar is provided on the surface of the first electrode bar close to the free end in the second direction, and the other weighted cross bar is provided on the surface of the second electrode bar close to the free end in the second direction. The distance between the weighted cross bar and the edge of the free end it is close to in the second direction is 0.005λ - 0.03λ, where λ is the wavelength of the surface acoustic wave propagating in the interdigital transducer structure.

2. The interdigital transducer structure according to claim 1, characterized in that, When the load structure is a primary weighted part, each primary weighted part includes at least two sub-weighted parts arranged along the second direction.

3. The interdigital transducer structure according to claim 1, characterized in that, The weighted connection bars include a first weighted connection bar and a second weighted connection bar. The second weighted connection bar and the second bus bar are connected by a weighted connection post at a position corresponding to the first electrode bar along the second direction. The first weighted connection bar and the first bus bar are connected by a weighted connection post at a position corresponding to the second electrode bar along the second direction.

4. The interdigital transducer structure according to claim 3, characterized in that, A secondary weighted portion is provided on each of the weighted connection posts.

5. The interdigital transducer structure according to claim 1, characterized in that, In the interdigital region, when the load structure is a weighted cross bar, an auxiliary weighted portion is provided at positions on the first electrode bar and the second electrode bar close to the two weighted cross bars; the auxiliary weighted portion is provided between the two weighted cross bars, or the auxiliary weighted portion is not provided between the two weighted cross bars.

6. The interdigital transducer structure according to any one of claims 1-5, characterized in that, The weighted connection bars include a first weighted connection bar and a second weighted connection bar. The projections of the first weighted connection bar in the first direction coincide, and the projections of the second weighted connection bar in the first direction coincide. The lengths of the first weighted connection bar and the second weighted connection bar in a direction parallel to the second direction are both 0.02λ - 0.25λ. The minimum distance between each free end and the weighted connection bar closest to it in a direction parallel to the second direction is 0.02λ - 0.4λ. The minimum distance between each free end and the bus bar closest to it in a direction parallel to the second direction is 1λ - 2λ; λ is the wavelength of the surface acoustic wave propagating in the interdigital transducer structure. When the load structure is a primary weighted portion, the lengths of the primary weighted portions in a direction parallel to the second direction are 0.5λ - 1λ; λ is the wavelength of the surface acoustic wave propagating in the interdigital transducer structure.

7. The interdigital transducer structure according to any one of claims 1-5, characterized in that, The weighted connection bars include a first weighted connection bar and a second weighted connection bar. Two adjacent first weighted connection bars along the first direction are staggered in the second direction, so that the projections of the two adjacent first weighted connection bars in the first direction do not coincide. Two adjacent second weighted connection bars along the first direction are staggered in the second direction, so that the projections of the two adjacent second weighted connection bars in the first direction do not coincide.

8. The interdigital transducer structure according to claim 7, characterized in that, The minimum distances between two adjacent first weighted connection bars along the first direction and their corresponding second electrode bars in the second direction are 0.02λ - 0.4λ and 0.1λ - 0.6λ respectively. The minimum distances between two adjacent second weighted connection bars along the first direction and their corresponding first electrode bars in the second direction are 0.02λ - 0.4λ and 0.1λ - 0.6λ respectively. The lengths of the first weighted connection bar and the second weighted connection bar in a direction 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.

9. A filter structure, the filter structure comprising the interdigital transducer structure according to any one of claims 1-8.

10. The filter structure according to claim 9, characterized in that, The filter structure further includes two reflection grating arrays, which are respectively arranged on both sides of the interdigital transducer structure along the first direction. Each reflection grating array is composed of at least two metal reflection bars and two sub-bus bars. The metal reflection bars are parallel to the second direction and arranged along the first direction. Two ends of each metal reflection bar in the second direction are respectively in contact with the two sub-bus bars. A reflection grating load structure is arranged at a position on the reflection grating array where the projection of the load structure of the interdigital transducer structure coincides with the first direction.

11. The filter structure according to claim 10, characterized in that, When the load structure of the interdigital transducer structure is a primary weighting portion, the reflection grating load structure is also a primary weighting portion. The primary weighting portion of the reflection grating array is located at a position on the metal reflection bar corresponding to the primary weighting portion of the interdigital transducer structure in the first direction.

12. The filter structure according to claim 11, characterized in that, When the primary weighting portion of the interdigital transducer structure is at least two sub-weighting portions, each primary weighting portion on the metal reflection bar is also at least two sub-weighting portions arranged along the second direction. The sub-weighting portions of the reflection grating array are located at positions on the metal reflection bar corresponding to the sub-weighting portions of the interdigital transducer structure in the first direction.

13. The filter structure according to claim 10, characterized in that, When the load structure of the interdigital transducer structure is a weighting cross bar, the reflection grating load structure is also a weighting cross bar. The weighting cross bar of the reflection grating array is connected to the weighting cross bar of the interdigital transducer structure and their projections coincide in the first direction.

14. The filter structure according to claim 13, characterized in that, When the interdigital transducer structure is provided with an auxiliary weighting portion, the reflection grating array is also provided with an auxiliary weighting portion. The auxiliary weighting portion of the reflection grating array is located at a position on the metal reflection bar corresponding to the auxiliary weighting portion of the interdigital transducer structure in the first direction.

15. An electronic device, the electronic device comprising the filter structure according to any one of claims 9-14.

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