Surface acoustic wave device and surface acoustic wave filter

Abstract

The present disclosure provides a surface acoustic wave device and a surface acoustic wave filter. The surface acoustic wave device comprises: a piezoelectric substrate; and an interdigital transducer configured to be arranged on a surface of the piezoelectric substrate; wherein the interdigital transducer comprises two parallel bus lines, each bus line is configured to connect a sub-bus line through a strip gate structure, the sub-bus line is configured to be connected with a plurality of first electrodes and a plurality of second electrodes arranged at intervals, wherein the first electrode of one sub-bus line is configured to be arranged opposite to the second electrode of the other sub-bus line along an electrode extension direction, and one end of the first electrode and the second electrode arranged opposite to each other is configured to have a preset end structure, wherein the length of the first electrode in the electrode extension direction is greater than the length of the second electrode in the electrode extension direction.

Description

Technical Field

[0001] This disclosure relates to the field of acoustic device technology, and more specifically, to a surface acoustic wave device and a surface acoustic wave filter. Background Technology

[0002] Surface acoustic waves (SAWs) are elastic waves that exist on the surface of a solid half-space and propagate along the surface, with their energy concentrated near the surface. Due to their high energy density and slow propagation speed, SAW devices have been widely used in products such as resonators, filters, and sensors.

[0003] Since surface acoustic waves (SAWs) are a type of sound wave, due to their inherent characteristics, SAW devices inevitably generate a significant number of transverse parasitic modes. In realizing the concept disclosed herein, the inventors discovered at least the following problems in the related technologies: improvements to SAW devices in the related technologies cannot effectively suppress transverse parasitic modes, resulting in a low quality factor for SAW devices. Summary of the Invention

[0004] In view of this, the present disclosure provides a surface acoustic wave device and a surface acoustic wave filter.

[0005] One aspect of this disclosure provides a surface acoustic wave device, comprising:

[0006] piezoelectric substrates; and

[0007] Interdigital transducers are configured to be disposed on the surface of the piezoelectric substrate described above;

[0008] The interdigitated transducer includes two parallel busbars, each of which is configured to connect to a sub-busbar via a strip grid structure. The sub-busbars are configured to connect to a plurality of first electrodes and a plurality of second electrodes spaced apart. The first electrode of one sub-busbar is configured to be opposite to the second electrode of the other sub-busbar along the electrode extension direction. The opposite ends of the first and second electrodes are each configured to have a preset end structure. The length of the first electrode in the electrode extension direction is greater than the length of the second electrode in the electrode extension direction.

[0009] According to an embodiment of the present disclosure, the preset end structure of the first electrode is configured to form a first edge region extending along the busbar extension direction, and the preset end structure of the second electrode is configured to form a second edge region extending along the busbar extension direction.

[0010] The first electrode is configured to have the preset end structure at the end that coincides with the first edge region, and / or to have the preset end structure at the end that coincides with the second edge region.

[0011] According to an embodiment of this disclosure, the widths of the first electrode and the second electrode are equal in the busbar extension direction, and the width of the preset end structure in the busbar extension direction is greater than the width of the first electrode or the second electrode in the busbar extension direction.

[0012] According to an embodiment of this disclosure, the interdigital transducer further includes a first metal strip structure, which is configured to be arranged parallel to the busbar and to connect a plurality of preset end structures of the second electrodes and the plurality of first electrodes.

[0013] According to an embodiment of this disclosure, the strip grid structure includes a plurality of second metal strip structures arranged in parallel at equal intervals, the second metal strip structures being configured to be arranged parallel to the busbar.

[0014] According to an embodiment of the present disclosure, the first electrode is configured to pass sequentially through the sub-busbar and the plurality of the second metal strip structures along the electrode extension direction to connect the busbar.

[0015] According to an embodiment of the present disclosure, the second electrode is configured to sequentially pass through the sub-busbar and the plurality of the second metal strip structures along the electrode extension direction to connect the busbar.

[0016] According to an embodiment of this disclosure, the strip grid structure further includes a plurality of third metal strip structures arranged in parallel at equal intervals, one end of each third metal strip structure being configured to connect to the busbar and the other end being configured to connect to the sub-busbar.

[0017] According to an embodiment of this disclosure, the third metal strip structure is configured such that its extension direction is parallel to the extension direction of the electrode.

[0018] Another aspect of this disclosure provides a surface acoustic wave filter, including at least one surface acoustic wave device as described above.

[0019] According to embodiments of this disclosure, by providing a second electrode in the region between the first electrode and the busbar, and by providing a preset end structure at one end opposite to the first electrode and the second electrode, the propagation speed of the sound wave in the interdigital transducer is changed. This allows the interdigital transducer to filter out the remaining waveforms that are not piston waveforms, and the propagation mode of these waveforms conforms to the piston waveform pattern. Furthermore, by providing a strip grid structure between the busbar and the busbar, a short-circuit structure can be formed in the region between the busbar and the busbar to weaken the electric field strength in that region and suppress the propagation of sound waves in that region. Through the above structural configuration, the technical problems of the inability to effectively suppress transverse parasitic modes and the low quality factor of surface acoustic wave (SAW) devices in related technologies can be overcome at least partially, thereby effectively reducing the parasitic modes of SAW devices and enabling SAW devices to have a higher quality factor. Attached Figure Description

[0020] The above and other objects, features, and advantages of this disclosure will become clearer from the following description of embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0021] Figure 1 A top view of a surface acoustic wave device according to an embodiment of the present disclosure is shown schematically.

[0022] Figure 2 A partially enlarged schematic diagram of an interdigital transducer according to an embodiment of the present disclosure is shown.

[0023] Figure 3A A partially enlarged schematic diagram of an interdigital transducer according to another embodiment of the present disclosure is shown.

[0024] Figure 3B A partially enlarged schematic diagram of an interdigital transducer according to another embodiment of the present disclosure is shown.

[0025] Figure 3C A partially enlarged schematic diagram of an interdigital transducer according to another embodiment of the present disclosure is shown.

[0026] Figure 4 A top view of a surface acoustic wave device according to another embodiment of the present disclosure is shown schematically.

[0027] Figure 5A A schematic diagram of a strip grid structure according to an embodiment of the present disclosure is shown.

[0028] Figure 5B A top view of a surface acoustic wave device according to another embodiment of the present disclosure is shown schematically.

[0029] Figure 5C A top view of a surface acoustic wave device according to another embodiment of the present disclosure is shown schematically.

[0030] Figure 5D A top view of a surface acoustic wave device according to another embodiment of the present disclosure is shown schematically.

[0031] Figure 5E A top view of a surface acoustic wave device according to another embodiment of the present disclosure is shown schematically.

[0032] Figure 6 A top view of a surface acoustic wave device according to another embodiment of the present disclosure is shown schematically.

[0033] Figure 7 A schematic diagram of a surface acoustic wave resonator according to an embodiment of the present disclosure is shown.

[0034] Figure 8 A schematic diagram of a surface acoustic wave filter according to an embodiment of the present disclosure is shown.

[0035] Figure 9 A schematic diagram of a surface acoustic wave filter according to another embodiment of the present disclosure is shown. Detailed Implementation

[0036] The embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0037] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0038] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0039] When using expressions such as "at least one of A, B, and C," the expression should generally be interpreted in accordance with the meaning commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, and C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.). Similarly, when using expressions such as "at least one of A, B, or C," the expression should generally be interpreted in accordance with the meaning commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, or C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).

[0040] Surface acoustic waves (SAWs) are elastic waves that exist on the surface of a solid half-space and propagate along the surface, with their energy concentrated near the surface. Due to their high energy density and slow propagation speed, SAW devices are widely used in resonators, filters, sensors, and other products. For example, SAW filters can be made based on SAW devices and used as bandpass filters in high-frequency circuits. Furthermore, Lamb waves, Rayleigh waves, Raf waves, and horizontal shear waves based on SAW devices can be used to make resonators, and filters or duplexers can be designed by arranging multiple such resonators into a trapezoidal or lattice topology.

[0041] With the development of surface acoustic wave (SAW) device technology, SAW devices are evolving towards miniaturization, higher frequency, and wider bandwidth, while the power handling requirements for SAW devices are also increasing. Accordingly, a series of improved SAW devices have been proposed based on existing technologies, such as the buried temperature-compensated surface acoustic wave (TC-SAW) and the POI-SAW based on piezoelectric materials on an insulating substrate. However, since SAW is a type of sound wave, due to its inherent characteristics, SAW devices inevitably generate a significant number of transverse parasitic modes. Current improvements to SAW devices cannot effectively suppress these transverse parasitic modes while simultaneously meeting the aforementioned requirements.

[0042] For example, buried temperature-compensated surface acoustic wave (SAW) devices have a temperature compensation layer deposited on the piezoelectric substrate and electrode surface, thus exhibiting better temperature coefficient of frequency (TCF) and quality factor (Q value) compared to conventional SAW devices. However, this device exhibits a strong transverse mode, resulting in larger ripple in the passband and a decrease in overall insertion loss.

[0043] For example, surface acoustic wave (SAW) devices based on piezoelectric materials on insulating substrates are made by fabricating LiNbO3 and LiTaO3 into thin films for use in SAW devices. Compared with conventional SAW devices, they have better operating frequencies, equivalent coupling coefficients (k2eff), and quality factors. However, due to the poor frequency temperature coefficient of the piezoelectric layer in this device, a large frequency deviation will occur in the industrial temperature range (-20 to 85°C), which will deteriorate its insertion loss.

[0044] In view of this, embodiments of the present disclosure provide a surface acoustic wave (SAW) device and a SAW filter. The SAW device can effectively suppress transverse parasitic modes, thereby improving the device's quality factor and performance. Specifically, the SAW device provided in the embodiments of the present disclosure includes: a piezoelectric substrate; and an interdigital transducer configured to be disposed on the surface of the piezoelectric substrate. The interdigital transducer includes two parallel busbars, each busbar configured to connect to a sub-busbar via a strip-shaped grid structure. The sub-busbars are configured to connect to a plurality of spaced first electrodes and a plurality of second electrodes. The first electrode of one sub-busbar is configured to be opposite to the second electrode of the other sub-busbar along its electrode extension direction. The opposite ends of the first and second electrodes are each configured to have a preset end structure. The length of the first electrode in its electrode extension direction is greater than the length of the second electrode in its electrode extension direction.

[0045] Figure 1 A top view of a surface acoustic wave device according to an embodiment of the present disclosure is shown schematically.

[0046] like Figure 1 As shown, the surface acoustic wave device may include a piezoelectric substrate 100 and an interdigital transducer 200.

[0047] According to embodiments of this disclosure, piezoelectric substrate 100 may refer to a substrate made of piezoelectric material.

[0048] According to embodiments of this disclosure, the piezoelectric material used to fabricate the piezoelectric substrate 100 may include, but is not limited to, SiO2 (silicon dioxide), AlN (aluminum nitride), Al2O3 (aluminum oxide), LiNbO3 (lithium niobate), LiTaO3 (lithium tantalate), or the above-mentioned materials doped with other elements. The specific piezoelectric material used to fabricate the piezoelectric substrate 100 can be selected according to the application scenario and is not limited herein.

[0049] According to embodiments of this disclosure, the piezoelectric substrate 100 can exhibit both direct and inverse piezoelectric effects. Specifically, the direct piezoelectric effect refers to the phenomenon where, when the piezoelectric substrate 100 is deformed by an external force along a certain direction, polarization occurs inside the piezoelectric substrate 100, meaning that opposite charges appear on the two opposing surfaces of the piezoelectric substrate 100. When the external force is removed, the piezoelectric substrate 100 returns to its uncharged state. The inverse piezoelectric effect refers to the deformation of the piezoelectric substrate 100 when an electric field is applied in the polarization direction, which disappears when the applied electric field is removed.

[0050] According to embodiments of this disclosure, the piezoelectric substrate 100 can achieve acoustic-electric conversion based on the direct and inverse piezoelectric effects. Specifically, by applying a varying voltage, such as an alternating current voltage, to the piezoelectric substrate 100, the piezoelectric substrate 100 can be made to vibrate, thereby generating sound waves on the surface of the piezoelectric substrate 100. After the piezoelectric substrate 100 vibrates due to the received sound waves, it can generate a varying voltage due to polarization.

[0051] According to embodiments of this disclosure, the interdigital transducer 200 can be configured to be disposed on the surface of the piezoelectric substrate 100. The surface of the piezoelectric substrate 100 can refer to the surface of the piezoelectric substrate 100 that can generate and transmit sound waves.

[0052] According to an embodiment of this disclosure, the interdigital transducer 200 includes two parallel busbars 210. Each busbar is configured to connect to a sub-busbar 230 via a strip grid structure 220. The sub-busbar 230 is configured to connect to a plurality of spaced-apart first electrodes 240 and a plurality of second electrodes 250. The first electrode 240 of one sub-busbar is configured to be opposite to the second electrode 250 of the other sub-busbar along the electrode extension direction. The opposite ends of the first electrode 240 and the second electrode 250 are both configured to have a preset end structure 260. The length of the first electrode 240 in the electrode extension direction is greater than the length of the second electrode 250 in the electrode extension direction.

[0053] According to embodiments of this disclosure, the two buses 210 of the interdigital transducer 200 can be connected to the two ports of the surface acoustic wave device respectively, so as to receive externally input electrical signals through the ports or output electrical signals to the outside through the ports.

[0054] According to embodiments of this disclosure, the strip grid structure 220 may be composed of a plurality of intersecting metal strips. At least one of the plurality of metal strips may have its two ends connected to a busbar 210 and a sub-busbar 230, respectively, to achieve an electrical connection between the busbar 210 and the sub-busbar 230.

[0055] According to embodiments of this disclosure, the sub-bus 230 can be configured to be arranged parallel to the bus 210.

[0056] According to embodiments of this disclosure, the busbar 230 may be connected to staggered first electrodes 240 and second electrodes 250. The plurality of first electrodes 240 and the plurality of second electrodes 250 may be arranged in parallel, with a certain gap between adjacent electrodes, and the gap between any two adjacent electrodes may be equal.

[0057] According to embodiments of this disclosure, the electrode extension direction may refer to the direction of the long side of the first electrode 240. The electrode extension direction of the first electrode 240 or the second electrode 250 may be perpendicular to the extension direction of the generatrix 230, or the angle between the electrode extension direction of the first electrode 240 or the second electrode 250 and the extension direction of the generatrix 230 may be any value between 0 and 90°, and is not limited herein.

[0058] According to embodiments of this disclosure, the interdigital transducer 200 can be formed by the intersection of two interdigital electrode structures. Specifically, an interdigital electrode structure can consist of a busbar 210, a strip grid structure 220, a sub-busbar 230, and a plurality of first electrodes 240 and a plurality of second electrodes 250 connected to the sub-busbar 230. When the two interdigital electrode structures are intersected, the first electrode 240 of one interdigital electrode structure can be positioned opposite to the second electrode 250 of the other interdigital electrode structure. A certain gap can be left between the oppositely positioned first electrode 240 and second electrode 250, and the long side of the first electrode 240 and the long side of the second electrode 250 can be located on the same straight line.

[0059] According to embodiments of this disclosure, the preset end structure 260 can refer to a structure located at the edge of the first electrode 240 and the second electrode 250, and having a certain shape. The shape of the preset end structure 260 is not limited here; for example, it can be a matrix, triangle, rhombus, hexagon, etc. The specific dimensions of the preset end structure 260 can be determined according to the specific application scenario and are not limited here.

[0060] According to embodiments of this disclosure, by providing a second electrode in the region between the first electrode and the busbar, and by providing a preset end structure at one end opposite to the first electrode and the second electrode, the propagation speed of the sound wave in the interdigital transducer is changed. This allows the interdigital transducer to filter out the remaining waveforms that are not piston waveforms, and the propagation mode of these waveforms conforms to the piston waveform pattern. Furthermore, by providing a strip grid structure between the busbar and the busbar, a short-circuit structure can be formed in the region between the busbar and the busbar to weaken the electric field strength in that region and suppress the propagation of sound waves in that region. Through the above structural configuration, the technical problems of the inability to effectively suppress transverse parasitic modes and the low quality factor of surface acoustic wave (SAW) devices in related technologies can be overcome at least partially, thereby effectively reducing the parasitic modes of SAW devices and enabling SAW devices to have a higher quality factor.

[0061] The following is for reference. Figure 2 , Figures 3A-3C , Figure 4 , Figures 5A-5E and Figure 6 In conjunction with specific embodiments, Figure 1 The surface acoustic wave device shown will be further explained.

[0062] Figure 2 A partially enlarged schematic diagram of an interdigital transducer according to an embodiment of the present disclosure is shown.

[0063] like Figure 2 As shown, the lengths of the short sides of the first electrode 240 and the second electrode 250 can be equal, that is, the widths of the first electrode 240 and the second electrode 250 in the direction of extension of the busbar are equal, for example, both can be L.

[0064] According to embodiments of this disclosure, the duty cycle of the region where the first electrode 240 and the second electrode 250 are located in the interdigital transducer 200 can be L / P, where P can refer to the period of the electrode. P can be obtained by summing the width of the first electrode 240 and the width of the gap between two adjacent first electrodes 240.

[0065] According to embodiments of this disclosure, the width of the gap between the opposing first electrode 240 and the second electrode 250 can be GD, and the width of the busbar 230 can be WB. By setting the dimensions of GD and WB, the edge of the interdigital transducer 200 can be located at the peak of the S2 mode distribution, thereby reducing the S2 lateral mode.

[0066] According to embodiments of this disclosure, the preset end structure 260 can be a rectangular structure, and its dimensions along the electrode extension direction and the busbar extension direction can be Wm and Lm, respectively. Lm can be greater than L, that is, the width of the preset end structure 260 in the busbar extension direction can be greater than the width of the first electrode 240 or the second electrode 250 in the busbar extension direction.

[0067] According to embodiments of this disclosure, by providing the preset end structure 260, the sound velocity of each part in the interdigital transducer 200 can be affected. Specifically, the sound velocity in the region where the preset end structure 260 is located on the first electrode 240 and the region where the preset end structure 260 is located on the second electrode 250 will decrease, while the sound velocity in the region between the connection end of the first electrode 240 and the preset end structure 260, the region between the connection end of the second electrode 250 and the preset end structure 260, and the gap region between the first electrode 240 and the second electrode 250 will not be affected.

[0068] According to embodiments of this disclosure, the preset end structure 260 may also be disposed at other positions on the first electrode 240 to further adjust the sound velocity of each part in the interdigital transducer 200.

[0069] Figure 3A A partially enlarged schematic diagram of an interdigital transducer according to another embodiment of the present disclosure is shown.

[0070] like Figure 3A As shown, the predetermined end structure of the first electrode 240 can be configured to form a first edge region extending along the busbar extension direction. The first electrode 240 can be configured to have a predetermined end structure 260 at the end coinciding with the first edge region.

[0071] Figure 3B A partially enlarged schematic diagram of an interdigital transducer according to another embodiment of the present disclosure is shown.

[0072] like Figure 3B As shown, the predetermined end structure of the second electrode 250 can be configured to form a second edge region extending along the busbar extension direction. The first electrode 240 can be configured to have a predetermined end structure 260 at the end coinciding with the second edge region.

[0073] Figure 3C A partially enlarged schematic diagram of an interdigital transducer according to another embodiment of the present disclosure is shown.

[0074] like Figure 3C As shown, the first electrode 240 can be configured to have a preset end structure 260 at both the end coinciding with the first edge region and the end coinciding with the second edge region.

[0075] According to the embodiments of this disclosure, by setting the preset end structure 260, the sound velocity in the region between the preset end structure 260 and the busbar 230 can be lower than the sound velocity in the middle region of the interdigital transducer, thereby causing the surface acoustic wave device to exhibit a piston motion mode, effectively reducing the lateral mode.

[0076] Figure 4 A top view of a surface acoustic wave device according to another embodiment of the present disclosure is shown schematically.

[0077] like Figure 4 As shown, the interdigital transducer also includes a first metal strip structure 270.

[0078] According to embodiments of this disclosure, the first metal strip structure 270 may be made of a material with high conductivity, such as aluminum, copper, silver, etc.

[0079] According to an embodiment of the present disclosure, the first metal strip structure 270 can be configured to be arranged parallel to the busbar 230, and the first metal strip structure 270 is configured to connect the preset end structures 260 of the plurality of second electrodes 250 and the plurality of first electrodes 240, that is, the first metal strip structure 270 can be used to short-circuit the preset end structures 260 of the plurality of second electrodes 250 located on the same side.

[0080] According to embodiments of this disclosure, the width of the first metal strip structure 270 in the electrode extension direction may be greater than, equal to or less than the width of the preset end structure 260 in the electrode extension direction, and is not limited herein.

[0081] According to embodiments of this disclosure, the sound velocity in the region between the busbar 230 and the first metal strip structure 270 can be further reduced by connecting the first metal strip structure 270, so as to better suppress the transverse mode of the surface acoustic wave device.

[0082] Figure 5A A schematic diagram of a strip grid structure according to an embodiment of the present disclosure is shown.

[0083] like Figure 5A As shown, the strip grid structure 220 can be formed by cross-connecting a plurality of second metal strip structures 221 arranged in parallel at equal intervals and a plurality of third metal strip structures 222 arranged in parallel at equal intervals.

[0084] According to embodiments of this disclosure, the second metal strip structure 221 can be configured to be arranged parallel to the busbar 210.

[0085] According to embodiments of this disclosure, the width of the second metal strip structure 221 along the electrode extension direction and the gap width between every two second metal strip structures 221 can be used to configure the duty cycle of the strip gate structure 220. Specifically, the width of the second metal strip structure 221 along the electrode extension direction can be Wr, and the gap width between every two second metal strip structures 221 can be Wg, then the duty cycle of the strip gate structure 220 is Wr / (Wr+Wg).

[0086] According to embodiments of this disclosure, at least a portion of the plurality of third metal strip structures 222 can be connected to the busbar 210 and the sub-busbar 230 respectively to realize the connection between the busbar 210 and the sub-busbar 230. That is, one end of the portion of the third metal strip structure 222 can be configured to connect to the busbar 210, and the other end can be configured to connect to the sub-busbar 230.

[0087] According to the embodiments of this disclosure, the number of the second metal strip structure 221 and the third metal strip structure 222 in the strip gate structure 220 is not limited. That is, the density of the gate structure in the strip gate structure 220 along the electrode extension direction and the density along the busbar extension direction can be set to any value according to the characteristics of the surface acoustic wave device in the specific application scenario.

[0088] Figure 5B A top view of a surface acoustic wave device according to another embodiment of the present disclosure is shown schematically.

[0089] like Figure 5B As shown, compared to Figure 1 The surface acoustic wave device shown has a sparser gate structure along the electrode extension direction and a denser gate structure along the bus extension direction.

[0090] According to embodiments of this disclosure, Figure 5B The third metal strip structure 222 can also move any distance along the extension direction of the busbar to achieve a phase transition of the generated sound wave. Specifically, the period of the electrodes of the interdigital transducer 200 can be P, and the distance that the third metal strip structure 222 moves along the extension direction of the busbar can be p, then the phase transition of the sound wave is p / P*180°.

[0091] According to embodiments of this disclosure, the third metal strip structure 222 can be configured to be perpendicular to the second metal strip structure 221, that is, the third metal strip structure 222 can be configured to have its extension direction parallel to the electrode extension direction; or, the third metal strip structure 222 can also be configured to be inclined to the second metal strip structure 221 at any angle, which is not limited here.

[0092] Figure 5CA top view of a surface acoustic wave device according to another embodiment of the present disclosure is shown schematically.

[0093] like Figure 5C As shown, the second metal strip structure 221 can be configured to be parallel to the busbar 210, and the third metal strip structure 222 can be configured to be inclined relative to the electrode extension direction. The inclination angle, that is, the angle between the extension direction of the third metal strip structure 222 and the electrode extension direction, can be α.

[0094] In other embodiments of this disclosure, the first electrode 240 or the second electrode 250 may replace the third metal strip structure 222 to achieve the connection between the busbar 210 and the sub-busbar 230.

[0095] Figure 5D A top view of a surface acoustic wave device according to another embodiment of the present disclosure is shown schematically.

[0096] like Figure 5D As shown, the first electrode 240 can be configured to pass sequentially through the sub-busbar 230 and multiple second metal strip structures 221 along the electrode extension direction to connect to the busbar 210. That is, the multiple second metal strip structures 221 and the extension portion of the first electrode 240 can together constitute the strip-shaped grid structure 220.

[0097] Figure 5E A top view of a surface acoustic wave device according to another embodiment of the present disclosure is shown schematically.

[0098] like Figure 5E As shown, the second electrode 250 can be configured to pass sequentially through the sub-busbar 230 and multiple second metal strip structures 221 along the electrode extension direction to connect to the busbar 210. That is, the multiple second metal strip structures 221 and the extension portion of the second electrode 250 can together constitute the strip-shaped grid structure 220.

[0099] Figure 6 A top view of a surface acoustic wave device according to another embodiment of the present disclosure is shown schematically.

[0100] like Figure 6 As shown, the interdigital transducer 200 can be tilted. Specifically, the busbar 210, the strip grid structure 220, and the sub-busbar 230 can be tilted relative to the direction of acoustic wave propagation. This direction of acoustic wave propagation can be a direction perpendicular to the electrode extension direction on the surface of the piezoelectric substrate 100. The tilt angle can be 5°, 10°, 15°, etc., and is not limited here.

[0101] According to embodiments of this disclosure, by tilting the interdigital transducer 200, other types of transverse vibration modes can be further suppressed to improve the quality factor and performance of the surface acoustic wave device.

[0102] Figure 7 A schematic diagram of a surface acoustic wave resonator according to an embodiment of the present disclosure is shown.

[0103] like Figure 7 As shown, a surface acoustic wave resonator can be composed of a surface acoustic wave device and two reflective gratings on both sides, and the surface acoustic wave device and the two reflective gratings on both sides can share a piezoelectric substrate.

[0104] According to embodiments of this disclosure, the surface acoustic wave device can be as follows: Figure 1 , Figure 2 , Figures 3A-3C , Figure 4 , Figures 5A-5E and Figure 6 The surface acoustic wave device shown in any of the figures is described in detail in the above embodiments, and will not be repeated here.

[0105] According to the embodiments of this disclosure, by setting the structure of the surface acoustic wave device as described above and setting appropriate dimensions for each structure in combination with specific application scenarios, the transverse mode of the surface acoustic wave device can be fully suppressed, the quality factor of the surface acoustic wave device can be improved, and the overall performance of the surface acoustic wave resonator can be improved.

[0106] According to embodiments of this disclosure, such as Figure 7 The surface acoustic wave (SAW) resonators shown can be the basic units for constructing devices such as filters and sensors. By connecting multiple SAW resonators in series, parallel, and / or cascade, different topologies can be constructed to obtain filters, sensors, and other devices with different functions. For example, filters can be designed by connecting multiple SAW resonators to form a trapezoidal or lattice topology.

[0107] Figure 8 A schematic diagram of a surface acoustic wave filter according to an embodiment of the present disclosure is shown.

[0108] like Figure 8 As shown, the filter can be a trapezoidal filter constructed by cascading multiple surface acoustic wave (SAW) resonators. Each SAW resonator can consist of a single SAW device provided in this embodiment and two reflective gratings on both sides.

[0109] In another embodiment of this disclosure, the filter can also be constructed by arranging surface acoustic wave devices side by side.

[0110] Figure 9 A schematic diagram of a surface acoustic wave filter according to another embodiment of the present disclosure is shown.

[0111] like Figure 9As shown, the filter can be a DMS (Double Mode SAW) device composed of multiple interdigital transducers arranged side by side and reflective gratings on both sides. The multiple interdigital transducers and the reflective gratings on both sides can share a single piezoelectric substrate. The DMS device can have good left roll-off characteristics, and filters or duplex devices can be further designed based on this DMS device.

[0112] It should be noted that the surface acoustic wave device provided in the embodiments of this disclosure can also be used to make other filters, sensors and other devices. The original surface acoustic wave device in other filters, sensors and other devices can be replaced with the surface acoustic wave device provided in the embodiments of this disclosure, which will not be described in detail here.

[0113] Those skilled in the art will understand that the features described in the various embodiments and / or claims of this disclosure can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. In particular, the features described in the various embodiments and / or claims of this disclosure can be combined and / or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.

[0114] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A surface acoustic wave device, comprising: piezoelectric substrate; as well as Interdigital transducers are configured to be disposed on the surface of the piezoelectric substrate; The interdigitated transducer includes two parallel busbars, each busbar being configured to connect to a sub-busbar via a strip grid structure. The sub-busbar is configured to connect to a plurality of first electrodes and a plurality of second electrodes spaced apart. The first electrode of one sub-busbar is configured to be opposite to the second electrode of the other sub-busbar along the electrode extension direction. The opposite ends of the first electrode and the second electrode are both configured to have a preset end structure. The length of the first electrode in the electrode extension direction is greater than the length of the second electrode in the electrode extension direction. The strip grid structure is an intermediate coupling structure independent of the busbar and the sub-busbar. The strip grid structure includes multiple metal strips arranged in a cross pattern. At least one of the multiple metal strips has its two ends connected to the busbar and the sub-busbar respectively, so as to realize the electrical connection between the busbar and the sub-busbar.

2. The surface acoustic wave device according to claim 1, wherein, The preset end structure of the first electrode is configured to form a first edge region extending along the extension direction of the busbar, and the preset end structure of the second electrode is configured to form a second edge region extending along the extension direction of the busbar. The first electrode is configured to have the preset end structure at the end that coincides with the first edge region, and / or to have the preset end structure at the end that coincides with the second edge region.

3. The surface acoustic wave device according to claim 1 or 2, wherein, The widths of the first electrode and the second electrode are equal in the busbar extension direction, and the width of the preset end structure in the busbar extension direction is greater than the width of the first electrode or the second electrode in the busbar extension direction.

4. The surface acoustic wave device according to claim 1 or 2, wherein, The interdigital transducer further includes a first metal strip structure, which is configured to be arranged parallel to the busbar and is configured to connect a plurality of preset end structures of the second electrodes and the plurality of first electrodes.

5. The surface acoustic wave device according to claim 1 or 2, wherein, The strip grid structure includes a plurality of second metal strip structures arranged in parallel at equal intervals, the second metal strip structures being configured to be arranged parallel to the busbar.

6. The surface acoustic wave device according to claim 5, wherein, The first electrode is configured to connect the busbar by sequentially passing through the sub-busbar and a plurality of second metal strip structures along the electrode extension direction.

7. The surface acoustic wave device according to claim 5, wherein, The second electrode is configured to connect to the busbar by sequentially passing through the sub-busbar and a plurality of the second metal strip structures along the electrode extension direction.

8. The surface acoustic wave device according to claim 5, wherein, The strip grid structure also includes a plurality of third metal strip structures arranged in parallel at equal intervals. One end of each third metal strip structure is configured to connect to the busbar, and the other end is configured to connect to the sub-busbar.

9. The surface acoustic wave device according to claim 8, wherein, The third metal strip structure is configured to extend in a direction parallel to the extension direction of the electrode.

10. A surface acoustic wave filter, comprising at least one surface acoustic wave device according to any one of claims 1 to 9.

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