Surface acoustic wave filter and electronic device

Abstract

The utility model provides a surface acoustic wave filter and an electronic device. The surface acoustic wave filter comprises a piezoelectric substrate; the series arm resonator is located on a part of the surface of the piezoelectric substrate, the series arm resonator has a first inclination angle, and the first inclination angle is not zero; and the parallel arm resonator is located on a part of the surface of the piezoelectric substrate, the parallel arm resonator has a second inclination angle, and the second inclination angle is not zero. The IPD filter solves the problems that in the prior art, an IPD filter is large in passband insertion loss at a high frequency band and poor in rectangularity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of filters, in particular to a surface acoustic wave filter and an electronic device. BACKGROUND

[0002] With the development of communication technology from 2G to 5G, the number of communication frequency bands gradually increases (from 4 frequency bands of 2G to more than 50 frequency bands of 5G). In order to improve the compatibility of smart phones to different communication systems, the amount of filters required by 5G smart phones will increase significantly, which will promote the large-scale growth of the filter market. With the increasing demand for performance and stability of 5G communication systems, such as N77, N78, N79, 5G Wifi and other frequency bands, the demand for SAW (Surface Acoustic Wave) filter devices to make ultra-high frequency filters is also increasing day by day.

[0003] SAW has been widely used in <3GHz radio frequency filters, but for high frequency bands (>3GHz), most of the current applications are implemented in IPD (Integrated Passive Device). IPD is limited by poor rectangularity and large size, and cannot be applied to high-end devices. As a common filter method applied to high frequency bands, IPD usually has the characteristics of large insertion loss and poor rectangularity in the passband. CONTENT OF THE UTILITY MODEL

[0004] The main purpose of the present application is to provide a surface acoustic wave filter and an electronic device to solve the problem of large insertion loss and poor rectangularity of IPD filter in high frequency band in the prior art.

[0005] In order to achieve the above purpose, according to one aspect of the present application, a surface acoustic wave filter is provided, comprising: a piezoelectric substrate; a series arm resonator located on part of the surface of the piezoelectric substrate, the series arm resonator having a first tilt angle, the first tilt angle being not 0; and a parallel arm resonator located on part of the surface of the piezoelectric substrate, the parallel arm resonator having a second tilt angle, the second tilt angle being not 0.

[0006] Optionally, the series arm resonator comprises a first IDT (Interdigital Transducer) electrode, the first tilt angle is the tilt angle of the first IDT electrode, the parallel arm resonator comprises a second IDT electrode, and the second tilt angle is the tilt angle of the second IDT electrode.

[0007] Optionally, the series arm resonator comprises the first IDT electrode and a first reflector array arranged in parallel with the first IDT electrode, and the parallel arm resonator comprises the second IDT electrode and a second reflector array arranged in parallel with the second IDT electrode.

[0008] Optionally, the absolute value of the second tilt angle is greater than the absolute value of the first tilt angle.

[0009] Optionally, the first tilt angle is -5° to -45°, and the second tilt angle is -40° to -80°.

[0010] Optionally, the series arm resonator has a first rotation angle, and the parallel arm resonator has a second rotation angle, wherein the first rotation angle and the second rotation angle are both not 0, the first rotation angle is a rotation angle of the first IDT electrode, and the second rotation angle is a rotation angle of the second IDT electrode.

[0011] Optionally, when the wavelength of the series arm resonator is 0.8 μm to 1 μm, the first rotation angle is +4° to +6°; when the wavelength of the series arm resonator is 1 μm to 1.1 μm, the first rotation angle is +6° to +8°; when the wavelength of the series arm resonator is 1.1 μm to 1.2 μm, the first rotation angle is +6° to +10°; and when the wavelength of the series arm resonator is greater than 1.2 μm, the first rotation angle is +10° to +45°.

[0012] Optionally, when the wavelength of the parallel arm resonator is 0.8 μm to 1 μm, the second rotation angle is +4° to +8°; when the wavelength of the parallel arm resonator is 1 μm to 1.1 μm, the second rotation angle is +6° to +10°; and when the wavelength of the parallel arm resonator is greater than 1.1 μm, the second rotation angle is +10° to +45°.

[0013] Optionally, the piezoelectric substrate comprises a substrate and a piezoelectric layer stacked together, the series arm resonator is located on a part of the surface of the piezoelectric layer away from the substrate, the parallel arm resonator is located on a part of the surface of the piezoelectric layer away from the substrate, and the material of the piezoelectric layer and the material of the substrate are both high sound velocity materials.

[0014] Optionally, the material of the substrate is silicon carbide, and the material of the piezoelectric layer is lithium niobate.

[0015] According to another aspect of the present application, an electronic device is provided, comprising any of the surface acoustic wave filters.

[0016] According to the technical scheme, the surface acoustic wave filter comprises a piezoelectric substrate, a series arm resonator and a parallel arm resonator, wherein the series arm resonator and the parallel arm resonator are located on the piezoelectric substrate, the series arm resonator and the parallel arm resonator have a first tilt angle and a second tilt angle respectively, and the first tilt angle and the second tilt angle are both not 0. Compared with the IPD filter in the prior art, the series arm resonator and the parallel arm resonator have the first tilt angle and the second tilt angle respectively, and the first tilt angle and the second tilt angle are both not 0. Through the design of the tilt angle, the influence of the body wave (the acoustic wave propagating from the base material) on the performance of the SAW filter can be effectively suppressed, especially the radiation of the body wave in the passband can be avoided, the in-band loss is reduced, the out-of-band suppression is improved, the transverse mode is a common problem of the SAW device in the high frequency band, the design of the tilt angle can reduce the interference of the transverse mode, so that the unwanted transverse acoustic wave propagation can be suppressed, and the filter's rectangularity is improved, the out-of-band interference is reduced, and the signal quality in the passband is maintained. BRIEF DESCRIPTION OF DRAWINGS

[0017] The drawings constituting a part of the specification of the present application are used to provide further understanding of the present application, the illustrative embodiments of the present application and the description thereof are used to explain the present application, and do not constitute improper limitation on the present application. In the drawings:

[0018] Figure 1 A cross-sectional schematic view of a surface acoustic wave filter provided by an embodiment of the present application is shown;

[0019] Figure 2 A wafer schematic view provided by an embodiment of the present application is shown;

[0020] Figure 3 A schematic view of an electrode rotation angle provided by an embodiment of the present application is shown;

[0021] Figure 4 A schematic view of an electrode tilt angle provided by an embodiment of the present application is shown;

[0022] Fig. 5(a) shows a comparison of the admittance curves of the electrode tilt and the electrode non-tilt provided by an embodiment of the present application;

[0023] Fig. 5(b) shows a comparison of the real part of the admittance curves corresponding to Fig. 5(a) provided by an embodiment of the present application;

[0024] Fig. 6(a) shows a comparison of the admittance curves of the electrode rotation at different angles provided by an embodiment of the present application;

[0025] Fig. 6(b) shows a comparison of the real part of the admittance curves corresponding to Fig. 6(a) provided by an embodiment of the present application;

[0026] Figure 7 A schematic diagram of a specific electrode rotation angle is shown according to an embodiment of the present application;

[0027] Figure 8 A schematic diagram of a specific electrode tilt angle is shown according to an embodiment of the present application.

[0028] Wherein, the above figures include the following reference signs:

[0029] 11, piezoelectric substrate; 12, series arm resonator; 13, parallel arm resonator; 111, substrate; 112, piezoelectric layer; 14, resonator; 141, IDT electrode; 142, reflective grating array; 1411, first bus bar; 1412, second bus bar; 1413, first electrode finger; 1414, second electrode finger. DETAILED DESCRIPTION

[0030] It should be noted that the following detailed description is merely exemplary in nature and is intended to provide further description of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0031] It is to be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, components, and / or groups thereof, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0032] It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. In addition, it will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or connected to the other element through a third element.

[0033] As introduced in the background, the IPD filter in the prior art has a large passband insertion loss and poor rectangularity in the high frequency band. To solve the above problems, embodiments of the present application provide a surface acoustic wave filter and an electronic device.

[0034] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application.

[0035] The embodiments of the present application provide a surface acoustic wave filter, as shown in the following formula: Figure 1 The embodiments of the present application provide a surface acoustic wave filter, as shown in the following formula:

[0036] piezoelectric substrate 11;

[0037] series arm resonator 12, located on a part of the surface of the piezoelectric substrate 11, the series arm resonator 12 has a first tilt angle, and the first tilt angle is not 0;

[0038] parallel arm resonator 13, located on a part of the surface of the piezoelectric substrate 11, the parallel arm resonator 13 has a second tilt angle, and the second tilt angle is not 0.

[0039] Through the above embodiment, the surface acoustic wave filter includes a piezoelectric substrate, a series arm resonator and a parallel arm resonator, wherein the series arm resonator and the parallel arm resonator are located on the piezoelectric substrate, and the series arm resonator and the parallel arm resonator have a first tilt angle and a second tilt angle respectively, and the first tilt angle and the second tilt angle are not 0. Compared with the problem of large passband insertion loss and poor rectangularity of the IPD filter in the prior art, the series arm resonator and the parallel arm resonator have a first tilt angle and a second tilt angle respectively, and the first tilt angle and the second tilt angle are not 0. Through the design of the tilt angle, the influence of the body wave (the sound wave propagating from the base material) on the performance of the SAW filter can be effectively suppressed, especially the radiation of the body wave in the passband can be avoided, the in-band loss is reduced, the out-of-band suppression is improved, the transverse mode is a common problem of SAW devices at high frequency, and the design of the tilt angle can reduce the interference of the transverse mode, so that the unwanted transverse acoustic wave propagation can be suppressed, and the rectangularity of the filter is improved, the out-of-band interference is reduced, and the signal quality in the passband is maintained.

[0040] Specifically, the surface acoustic wave filter of the present application can realize the application of SAW in high frequency bands such as N77, N78, etc.

[0041] Specifically, in the high frequency band, the surface acoustic wave device is often affected by the transverse mode. By setting different tilt angles, the interference of the transverse mode can be reduced, thereby improving the rectangularity of the filter and reducing the out-of-band interference.

[0042] In an optional solution, the series arm resonator includes a first IDT electrode, the first tilt angle is the tilt angle of the first IDT electrode, the parallel arm resonator includes a second IDT electrode, and the second tilt angle is the tilt angle of the second IDT electrode. In this embodiment, the IDT electrode is a key component in the surface acoustic wave (SAW) filter, which is responsible for converting electrical signals into acoustic signals and converting acoustic signals back into electrical signals. By respectively setting IDT electrodes in the series arm resonator and the parallel arm resonator, the selectivity of the filter to a specific frequency can be enhanced, and the filtering performance can be improved.

[0043] According to some example embodiments of the present application, the series arm resonator includes the first IDT electrode and a first reflector array arranged at both ends of the first IDT electrode, and the parallel arm resonator includes the second IDT electrode and a second reflector array arranged at both ends of the second IDT electrode. In this embodiment, the first reflector array and the second reflector array are arranged to reflect the surface acoustic wave and reduce the loss of the wave, thereby enhancing the signal processing capability of the filter.

[0044] Specifically, the tilt angle of the resonator is the tilt angle of the IDT electrode in the resonator. The electrode tilt can effectively suppress the transverse mode.

[0045] According to some example embodiments of the present application, the absolute value of the second tilt angle is greater than the absolute value of the first tilt angle. In this embodiment, by setting the absolute value of the second tilt angle (the tilt angle of the parallel arm resonator) to be greater than the absolute value of the first tilt angle (the tilt angle of the series arm resonator), the propagation path of the acoustic wave in the resonator can be more effectively controlled, thereby further optimizing the performance of the surface acoustic wave (SAW) filter, which helps to further reduce the energy loss of the acoustic wave during propagation, and further improve the in-band insertion loss performance of the filter, i.e., further reduce the attenuation of the signal within the passband.

[0046] In yet another alternative, the first tilt angle is -5° to -45°, and the second tilt angle is -40° to -80°. In this embodiment, by setting the tilt angle of the series arm electrode to be -5° to -45° and the tilt angle of the parallel arm electrode to be -40° to -80°, the transverse mode acoustic wave can be further effectively suppressed, and the resonant characteristics can be adjusted, thereby further improving the passband rectangularity and stability of the filter at high frequencies.

[0047] According to some example embodiments of the present application, the series arm resonator has a first rotation angle, and the parallel arm resonator has a second rotation angle, neither of which is 0. The first rotation angle is the rotation angle of the first IDT electrode, and the second rotation angle is the rotation angle of the second IDT electrode. In this embodiment, by setting the first rotation angle and the second rotation angle to be non-zero, the Rayleigh mode can be effectively suppressed, and the rectangularity of the filter, i.e., the flatness of the signal within the passband and the out-of-band suppression capability, can be further optimized.

[0048] Specifically, the rotation angle of the resonator is the rotation angle of the IDT electrode in the resonator. The electrode rotation can effectively suppress the Rayleigh mode.

[0049] In other embodiments, when the wavelength of the series arm resonator is 0.8-1 μm, the first rotation angle is +4°-+6°; when the wavelength of the series arm resonator is 1-1.1 μm, the first rotation angle is +6°-+8°; when the wavelength of the series arm resonator is 1.1-1.2 μm, the first rotation angle is +6°-+10°; and when the wavelength of the series arm resonator is greater than 1.2 μm, the first rotation angle is +10°-+45°. In this embodiment, by adjusting the first rotation angle, the performance of the filter can be optimized according to the wavelength change of the series arm resonator. Different wavelengths correspond to different rotation angles, which helps to further adjust the frequency response curve of the filter and further improve its selectivity and out-of-band rejection capability.

[0050] Specifically, for the series arm resonator, the first rotation angle varies according to the wavelength change of the series arm resonator.

[0051] According to some optional schemes of the present application, when the wavelength of the parallel arm resonator is 0.8-1 μm, the second rotation angle is +4°-+8°; when the wavelength of the parallel arm resonator is 1-1.1 μm, the second rotation angle is +6°-+10°; and when the wavelength of the parallel arm resonator is greater than 1.1 μm, the second rotation angle is +10°-+45°. In this embodiment, by adjusting the second rotation angle, the performance of the filter can be optimized according to the wavelength change of the parallel arm resonator. Different wavelengths correspond to different rotation angles, which helps to further adjust the frequency response curve of the filter and further improve its selectivity and out-of-band rejection capability.

[0052] Specifically, for the parallel arm resonator, the second rotation angle varies according to the wavelength change of the parallel arm resonator.

[0053] Specifically, when the resonator is tilted, the IDT electrode and the reflection grating array located at both ends of the IDT electrode are tilted together; and when the resonator is rotated, the IDT electrode and the reflection grating array located at both ends of the IDT electrode are rotated together.

[0054] Specifically, in the wafer preparation process, the wafer direction needs to be determined, so a fixed notch is generally left in a certain direction, such as Figure 2 For the convenience of illustration, the upward direction is defined as the positive direction. Figure 3The diagram illustrates the definition of the electrode rotation angle. It is stipulated that when the direction of the IDT electrode interdigitation point in the resonator is consistent with the positive direction, the resonator has a 0° rotation angle; when the direction of the IDT electrode interdigitation point in the resonator rotates clockwise along the positive direction, the resonator is rotating in the positive direction, and the rotation angle is the positive rotation angle; when the direction of the IDT electrode interdigitation point in the resonator rotates counterclockwise along the positive direction, the resonator is rotating in the negative direction, and the rotation angle is the negative rotation angle. Figure 4 The diagram illustrates the definition of the electrode tilt angle. The tilt angle is defined as follows: the interdigitated direction of the IDT electrodes in the resonator is always aligned with the positive direction. It is stipulated that when the interdigitated direction of the IDT electrodes in the resonator is aligned with the positive direction, the resonator has a 0° tilt angle. When the entire resonator tilts clockwise along the positive direction (left side of the reflector array is higher than right side), the resonator is positively tilted, and the angle of rotation is a positive tilt angle. When the entire resonator tilts counterclockwise along the positive direction (left side of the reflector array is lower than right side), the resonator is negatively tilted, and the angle of rotation is a negative tilt angle.

[0055] Specifically, Figure 3 and Figure 4 The resonator in the circuit is either a series arm resonator or a parallel arm resonator. Figure 3 and Figure 4 wafers and Figure 2 The wafers in the same container are identical.

[0056] Specifically, Figures 5(a) and 5(b) show a performance comparison between tilted and non-tilted electrodes. In Figures 5(a) and 5(b), the solid line represents the tilted electrode, and the dashed line represents the non-tilted electrode. Figure 5(a) shows the admittance curve, with the horizontal axis freq representing frequency in GHz and the vertical axis representing admittance gain in dB. Figure 5(b) shows the real part admittance curve corresponding to Figure 5(a), with the horizontal axis freq representing frequency in GHz and the vertical axis representing real part admittance gain in dB. As can be seen from Figure 5, the solid line is smoother than the dashed line, indicating that electrode tilting can effectively suppress transverse modes.

[0057] Specifically, FIG. 6(a) and FIG. 6(b) show performance comparison diagrams of electrodes rotating different angles. In FIG. 6(a) and FIG. 6(b), the solid line is for the electrode rotating 2°, and the dashed line is for the electrode rotating 10°. FIG. 6(a) shows the admittance curve, where the horizontal axis freq represents frequency (Frequency) in GHz, and the vertical axis represents admittance gain in decibel (dB). FIG. 6(b) shows the admittance real part curve corresponding to FIG. 6(a), where the horizontal axis freq represents frequency (Frequency) in GHz, and the vertical axis represents admittance real part gain in decibel (dB). As can be seen from FIG. 6, the solid line is smoother than the dashed line, and the electrode rotation can effectively suppress the Rayleigh mode.

[0058] Specifically, as shown in Figure 7 and Figure 8 , the resonator 14 includes the IDT electrode 141 and the reflection grating array 142 arranged in parallel at both ends of the IDT electrode 141, the IDT electrode 141 includes the first bus bar 1411 and the second bus bar 1412, and the IDT electrode 141 further includes a plurality of first electrode fingers 1413 and a plurality of second electrode fingers 1414, the first bus bar 1411 is connected to the plurality of first electrode fingers 1413, the second bus bar 1412 is connected to the plurality of second electrode fingers 1414, and the plurality of first electrode fingers 1413 and the plurality of second electrode fingers 1414 are alternately inserted with each other. As shown in Figure 7 , the rotation angle a is the included angle between the positive direction and the direction A in which the first bus bar 1411 and the second bus bar 1412 extend. As shown in Figure 8 , the tilt angle b is the included angle between the direction B in which the first electrode finger 1413 and the second electrode finger 1414 extend and the direction C in which the elastic wave propagates, and the positive direction is perpendicular to the direction C in which the elastic wave propagates.

[0059] Specifically, Figure 7 and Figure 8 , the resonator 14 is a series arm resonator or a parallel arm resonator. Figure 7 and Figure 8 , the wafer is the same as the wafer in Figure 2 .

[0060] According to some optional schemes of the present application, as shown in Figure 1As shown, the piezoelectric substrate 11 includes a substrate 111 and a piezoelectric layer 112 stacked together, the material of the substrate 111 and the piezoelectric layer 112 is a high acoustic velocity material, the series arm resonator 12 is located on a part of the surface of the piezoelectric layer 112 away from the substrate 111, and the parallel arm resonator 13 is located on a part of the surface of the piezoelectric layer 112 away from the substrate 111. In this embodiment, the material of the substrate and the piezoelectric layer is a high acoustic velocity material. High acoustic velocity means that the SAW device can have a shorter wavelength at the same frequency, which is conducive to further realizing a smaller device size, and high acoustic velocity also helps to further reduce the interference of bulk waves.

[0061] In other embodiments, the material of the substrate is silicon carbide, and the material of the piezoelectric layer is lithium niobate. In this embodiment, the material of the substrate is silicon carbide, and the material of the piezoelectric layer is lithium niobate. Lithium niobate is a material with high electromechanical coupling coefficient, which means it can more effectively convert electrical energy into acoustic energy. In a surface acoustic wave (SAW) device, high electromechanical coupling coefficient can improve the conversion efficiency of the filter and reduce energy loss during signal transmission, thereby realizing low insertion loss. Silicon carbide is a material with very high acoustic velocity. High acoustic velocity means that the SAW device can have a shorter wavelength at the same frequency, which is conducive to further realizing a smaller device size, and high acoustic velocity also helps to further reduce the interference of bulk waves. The low loss characteristics of SIC also help to reduce energy loss during signal transmission.

[0062] Specifically, SIC material has high acoustic velocity, and LN (lithium niobate) has large electromechanical coupling coefficient, so that large bandwidth filtering performance can be realized in the high frequency band.

[0063] In summary, the surface acoustic wave filter with high acoustic velocity substrate SIC and high acoustic velocity piezoelectric layer LN + inclined electrode + rotating electrode combination can be applied to the high frequency band.

[0064] The embodiments of the present application also provide an electronic device including any of the above-mentioned surface acoustic wave filters.

[0065] Specifically, the electronic device includes but is not limited to a smartphone, a tablet computer, and a sensor.

[0066] From the above description, it can be seen that the embodiments of the present application achieve the following technical effects:

[0067] In the surface acoustic wave filter of the present application, the surface acoustic wave filter comprises a piezoelectric substrate, a series arm resonator and a parallel arm resonator, wherein the series arm resonator and the parallel arm resonator are both located on the piezoelectric substrate, the series arm resonator and the parallel arm resonator have a first tilt angle and a second tilt angle respectively, and the first tilt angle and the second tilt angle are both not 0. Compared with the problems of large passband insertion loss and poor rectangularity of the IPD filter in the prior art, the series arm resonator and the parallel arm resonator have the first tilt angle and the second tilt angle respectively, and the first tilt angle and the second tilt angle are both not 0. Through the design of the tilt angle, the influence of the bulk wave (the acoustic wave propagating in the base material) on the performance of the SAW filter can be effectively suppressed, especially the radiation of the bulk wave in the passband can be avoided, the in-band loss can be reduced, the out-of-band suppression can be improved, the transverse mode is a common problem of the SAW device at high frequency, the design of the tilt angle can reduce the interference of the transverse mode, so that the unwanted transverse acoustic wave propagation can be suppressed, and then the rectangularity of the filter can be improved, the out-of-band interference can be reduced, and the signal quality in the passband can be maintained.

[0068] The above only describes the preferred embodiments of the present application and is not used to limit the present application. The present application can have various changes and modifications for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A surface acoustic wave filter, characterized by, include: Piezoelectric substrate; A series arm resonator is located on a portion of the surface of the piezoelectric substrate, and the series arm resonator has a first tilt angle, which is not 0. A parallel arm resonator is located on a portion of the surface of the piezoelectric substrate, and the parallel arm resonator has a second tilt angle, which is not 0.

2. The surface acoustic wave filter according to claim 1, characterized by, The series arm resonator includes a first IDT electrode, and the first tilt angle is the tilt angle of the first IDT electrode. The parallel arm resonator includes a second IDT electrode, and the second tilt angle is the tilt angle of the second IDT electrode.

3. The surface acoustic wave filter according to claim 2, characterized by, The series arm resonator includes a first IDT electrode arranged in parallel and a first reflective grid array disposed at both ends of the first IDT electrode, and the parallel arm resonator includes a second IDT electrode arranged in parallel and a second reflective grid array disposed at both ends of the second IDT electrode.

4. The surface acoustic wave filter according to claim 2, wherein The absolute value of the second tilt angle is greater than the absolute value of the first tilt angle.

5. The surface acoustic wave filter according to claim 4, wherein The first tilt angle is -5° to -45°, and the second tilt angle is -40° to -80°.

6. The surface acoustic wave filter according to claim 5, wherein The series arm resonator has a first rotation angle, and the parallel arm resonator has a second rotation angle. Neither the first rotation angle nor the second rotation angle is 0. The first rotation angle is the rotation angle of the first IDT electrode, and the second rotation angle is the rotation angle of the second IDT electrode.

7. The surface acoustic wave filter according to claim 6, characterized by, When the wavelength of the series arm resonator is 0.8μm to 1μm, the first rotation angle is +4° to +6°; when the wavelength of the series arm resonator is 1μm to 1.1μm, the first rotation angle is +6° to +8°; when the wavelength of the series arm resonator is 1.1μm to 1.2μm, the first rotation angle is +6° to +10°; and when the wavelength of the series arm resonator is greater than 1.2μm, the first rotation angle is +10° to +45°.

8. The surface acoustic wave filter according to claim 6, wherein When the wavelength of the parallel arm resonator is 0.8μm to 1μm, the second rotation angle is +4° to +8°; when the wavelength of the parallel arm resonator is 1μm to 1.1μm, the second rotation angle is +6° to +10°; when the wavelength of the parallel arm resonator is greater than 1.1μm, the second rotation angle is +10° to +45°.

9. The surface acoustic wave filter according to claim 1, wherein, The piezoelectric substrate includes a stacked substrate and a piezoelectric layer. The series arm resonator is located on a portion of the piezoelectric layer away from the substrate, and the parallel arm resonator is located on a portion of the piezoelectric layer away from the substrate. Both the piezoelectric layer and the substrate are made of high-velocity materials.

10. The surface acoustic wave filter according to claim 9, characterized by, The substrate is made of silicon carbide, and the piezoelectric layer is made of lithium niobate.

11. An electronic device, comprising: The surface acoustic wave filter includes any one of claims 1 to 10.

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