WO2023193499A1 - 声表面波谐振器及声表面波滤波器 - Google Patents

声表面波谐振器及声表面波滤波器 Download PDF

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Publication number
WO2023193499A1
WO2023193499A1 PCT/CN2023/070901 CN2023070901W WO2023193499A1 WO 2023193499 A1 WO2023193499 A1 WO 2023193499A1 CN 2023070901 W CN2023070901 W CN 2023070901W WO 2023193499 A1 WO2023193499 A1 WO 2023193499A1
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Prior art keywords
bus bar
finger
acoustic wave
surface acoustic
wave resonator
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PCT/CN2023/070901
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English (en)
French (fr)
Inventor
刘贤栋
高安明
姜伟
张海力
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浙江星曜半导体有限公司
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Publication of WO2023193499A1 publication Critical patent/WO2023193499A1/zh

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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/25—Constructional features of resonators using surface acoustic waves
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02—Details
    • H03H9/02535—Details of surface acoustic wave devices
    • H03H9/02637—Details concerning reflective or coupling arrays
    • H03H9/02685—Grating lines having particular arrangements
    • H03H9/02763—Left and right side electrically coupled reflectors
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02—Details
    • H03H9/125—Driving means, e.g. electrodes, coils
    • H03H9/145—Driving means, e.g. electrodes, coils for networks using surface acoustic waves
    • H03H9/14544—Transducers of particular shape or position
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/46—Filters
    • H03H9/64—Filters using surface acoustic waves
    • H03H9/6489—Compensation of undesirable effects
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

Definitions

  • Embodiments of the present application relate to the technical field of surface acoustic wave filters, and in particular, to a surface acoustic wave resonator and a surface acoustic wave filter.
  • the surface acoustic wave filter is a passive bandpass filter made by utilizing the piezoelectric effect and the physical characteristics of surface acoustic wave propagation. Its function is to filter and delay electrical signals. It has the advantages of small size, stable performance, strong overload capability, small phase distortion, and no need for adjustment. It is widely used in televisions, video recorders, wireless data transmission systems and other fields.
  • the surface acoustic wave filter includes a support substrate, a temperature compensation layer and a piezoelectric substrate that are stacked in sequence, and a surface acoustic wave resonator arranged on the piezoelectric substrate.
  • the main working principle of the surface acoustic wave resonator is to use the piezoelectric properties of the piezoelectric substrate to input electrical signals to the surface acoustic wave resonator.
  • the input electrical signal completes the electrical signal-acoustic signal-electrical signal in the surface acoustic wave resonator. conversion to achieve the goal of filtering unnecessary signals and noise and improving reception quality.
  • a temperature compensation layer with an opposite temperature coefficient to the piezoelectric substrate is usually deposited under the piezoelectric substrate.
  • the effect requires thinning of the piezoelectric substrate.
  • the surface acoustic wave resonator when the thickness of the piezoelectric substrate is close to the wavelength ⁇ of the acoustic wave propagating in the surface acoustic wave resonator (that is, the thickness of the piezoelectric substrate is less than 10 ⁇ ), the surface acoustic wave resonator will generate a transverse resonance mode, and the transverse resonance mode This will cause sharp transmission zeros to appear in the passband of the surface acoustic wave filter, thereby reducing the performance of the surface acoustic wave filter.
  • the present application provides an embodiment of a surface acoustic wave resonator and a surface acoustic wave filter to solve the technical problem that the surface acoustic wave resonator generates a transverse resonance mode.
  • Embodiments of the present application provide a surface acoustic wave resonator, including an interdigital electrode.
  • the interdigital electrode includes a first bus bar and a second bus bar arranged oppositely.
  • the first bus bar is connected to a first bus bar along a first direction.
  • the second bus bar is connected to a plurality of first false fingers and a plurality of second finger strips alternately arranged along the first direction;
  • a plurality of first finger strips correspond to a plurality of first false fingers one by one, the corresponding first finger strips and the first false fingers are located on the same straight line, and the first finger strips and There is a first gap between the first false fingers;
  • the plurality of second finger strips correspond to the plurality of second false fingers one by one, the corresponding second finger strips and the second false fingers are located on the same straight line, and the second finger strips and There is a second gap between the second false fingers;
  • an end of the first finger bar away from the first bus bar and an end of the second finger bar away from the second bus bar are The distance between one end is a finger aperture, a plurality of first finger apertures and a plurality of second finger apertures form a plurality of finger apertures, and at least some of the finger apertures in the plurality of finger apertures are The apertures of the strips are not equal.
  • the surface acoustic wave resonator of the embodiment of the present application changes at least part of the finger apertures in the interdigital electrodes so that at least part of the plurality of finger apertures have different finger apertures.
  • the existence of different finger apertures on the surface wave resonator can reduce the lateral resonance mode, thereby achieving the effect of the surface acoustic wave resonator suppressing the lateral resonance mode.
  • the first direction is perpendicular to the length direction of the first finger strips, and a plurality of first finger strips and a plurality of second finger strips are alternately arranged along the first direction.
  • the apertures of the plurality of finger strips formed by the strips first increase and then decrease or show a wave-like increasing and decreasing trend.
  • At least one of the first bus bar and the second bus bar is an n-order fractal structure, and the n-order fractal structure includes 2 n-1 first-order fractals connected in sequence.
  • Structure, n is a positive integer;
  • the first-order fractal structure includes a connected first connecting bar and a second connecting bar. An end of the first connecting bar away from the second connecting bar and an end of the second connecting bar away from the first connecting bar. A connection line at one end is located between the first bus bar and the second bus bar;
  • the angle between the first connecting strip and the first straight line is a first deflection angle
  • the angle between the second connecting strip and the first straight line is a second deflection angle
  • the first straight line is perpendicular to In the first finger bar, the first deflection angle and the second deflection angle are both acute angles;
  • the 2 n-1 first-order fractal structures in the n-order fractal structure form 2 n-1 first deflection angles and 2 n-1 second deflection angles, and among the 2 n-1 first deflection angles
  • the angle range of at least part of the first deflection angle is 2°-16°
  • the angle range of at least part of the second deflection angles among the 2 n-1 second deflection angles is 2°-16°.
  • one of the first bus bar and the second bus bar is the n-order fractal structure, and the other one is a linear structure.
  • the first bus bar is the n-order fractal structure
  • the second bus bar is the linear structure
  • the surface acoustic wave resonator includes two interdigital electrodes in a cascade structure, the two interdigital electrodes share a second bus bar, and each of the two interdigital electrodes includes a first bus bar. strips, and the first bus bars of the two interdigital electrodes are located on both sides of the second bus bar.
  • the first bus bar and the second bus bar are both n-order fractal structures, and the first bus bar and the second bus bar are symmetrical along the first center line, so The first centerline is perpendicular to the first finger strip and passes through the center of the interdigital electrode.
  • both the first bus bar and the second bus bar have the n-order fractal structure, and multiple connecting bars of the first bus bar and the second bus bar are mutually connected. Corresponds to parallel.
  • the lengths of each of the first false fingers are the same, and the lengths of at least some of the first finger strips among the plurality of first finger strips are unequal;
  • Each of the second false fingers has the same length, and at least some of the second finger strips among the plurality of second finger strips have unequal lengths.
  • it further includes two reflection gratings, the two reflection gratings are arranged at both ends of the interdigital electrode in a direction perpendicular to the first finger strip, and the two reflection gratings There is a space between the grid and the interdigital electrode, and the two reflection grids are used to reflect the acoustic wave signal leaked to both ends of the interdigital electrode back to the interdigital electrode.
  • the number of the interdigital electrodes is multiple, the plurality of interdigital electrodes are arranged in series in a direction perpendicular to the first finger bar, and the two reflection gratings are arranged in series along a direction perpendicular to the first finger strip.
  • the first finger bar is provided at both ends of a plurality of interdigital electrodes connected in series, and there is a space between the two reflection gratings and the plurality of interdigital electrodes connected in series.
  • Embodiments of the present application also provide a surface acoustic wave filter.
  • the surface acoustic wave filter includes a support substrate, a temperature compensation layer and a piezoelectric substrate that are stacked in sequence, and a surface acoustic wave filter provided on the piezoelectric substrate.
  • a surface acoustic wave resonator, the surface acoustic wave resonator is the surface acoustic wave resonator described in any of the above solutions.
  • the beneficial effects of the surface acoustic wave filter in the embodiment of the present application are the same as the beneficial effects of the above-mentioned surface acoustic wave resonator, and will not be described again here.
  • the surface acoustic wave resonators and surface acoustic wave filters provided by the present application have Other technical problems that can be solved, other technical features included in the technical solution, and the beneficial effects brought by these technical features will be further described in detail in the specific implementation modes.
  • Figure 1 is a schematic structural diagram of several first bus bars and second bus bars of the surface acoustic wave resonator in the embodiment of the present application;
  • Figure 2 is a schematic structural diagram of a surface acoustic wave resonator in an embodiment of the present application
  • Figure 3 is a test comparison chart between the surface acoustic wave resonator in Figure 2 and the surface acoustic wave resonator with unsuppressed transverse resonance mode;
  • Figure 4 is another structural schematic diagram of a surface acoustic wave resonator in an embodiment of the present application.
  • Figure 5 is a test comparison chart between the surface acoustic wave resonator in Figure 4 and the surface acoustic wave resonator with unsuppressed transverse resonance mode;
  • Figure 6 is another structural schematic diagram of a surface acoustic wave resonator in an embodiment of the present application.
  • Figure 7 is a test comparison chart between the surface acoustic wave resonator in Figure 6 and the surface acoustic wave resonator with unsuppressed transverse resonance mode;
  • Figure 8 is another structural schematic diagram of a surface acoustic wave resonator in an embodiment of the present application.
  • Figure 9 is a schematic structural diagram of a surface acoustic wave resonator with two interdigital electrodes in a cascade structure
  • Figure 10 is another structural schematic diagram of a surface acoustic wave resonator with two interdigital electrodes in a cascade structure
  • Figure 11 is a schematic structural diagram of a surface acoustic wave resonator formed by two interdigital electrodes connected in series;
  • Figure 12 is another structural schematic diagram of a surface acoustic wave resonator in an embodiment of the present application.
  • Figure 13 is another structural schematic diagram of a surface acoustic wave resonator with two interdigital electrodes in a cascade structure.
  • a temperature compensation layer with an opposite temperature coefficient to the piezoelectric substrate is usually deposited under the piezoelectric substrate.
  • the effect requires thinning of the piezoelectric substrate.
  • the thickness of the piezoelectric substrate is close to the wavelength ⁇ of the acoustic wave propagating in the surface acoustic wave resonator (that is, the thickness of the piezoelectric substrate is less than 10 ⁇ )
  • the surface acoustic wave resonator will excite more complex acoustic wave modes.
  • the transverse resonance mode has a significant amplitude between the forward and reverse resonance peaks of the surface acoustic wave resonator.
  • the transverse resonance mode close to the forward and reverse resonance peaks will cause surface acoustic wave filtering. Sharp transmission zeros appear in the passband of the filter, thereby reducing the performance of the surface acoustic wave filter.
  • embodiments of the present application change at least part of the finger apertures in the interdigital electrodes so that at least part of the plurality of finger apertures have different finger apertures.
  • Different finger apertures on the surface acoustic wave resonator have different It is possible to reduce the transverse resonant mode, thereby achieving the effect of the surface acoustic wave resonator suppressing the transverse resonant mode.
  • Figure 1 is a schematic structural diagram of the first bus bar and the second bus bar of the surface acoustic wave resonator in the embodiment of the present application
  • Figure 2 is a schematic structural diagram of the surface acoustic wave resonator in the embodiment of the present application
  • Figure 3 It is a test comparison diagram of the surface acoustic wave resonator in Figure 2 and the surface acoustic wave resonator with unsuppressed transverse resonance mode
  • Figure 4 is another structural schematic diagram of the surface acoustic wave resonator in the embodiment of the present application
  • Figure 5 is The test comparison diagram between the surface acoustic wave resonator in Figure 4 and the surface acoustic wave resonator with unsuppressed transverse resonance mode
  • Figure 6 is another structural schematic diagram of the surface acoustic wave resonator in the embodiment of the present application
  • Figure 7 is a diagram Test comparison diagram of the surface acoustic wave resonator in 6 and the surface acoustic
  • the surface acoustic wave resonator provided by the embodiment of the present application includes an interdigital electrode 100.
  • the interdigital electrode 100 includes a first bus bar 110 and is connected to the first bus bar 110.
  • a plurality of first finger strips 111 and a plurality of second false fingers 112 are alternately arranged along the first direction on the first bus bar 110.
  • the plurality of first false fingers 121 and the plurality of second finger strips 122 are arranged on the second bus bar 110.
  • the bus bars 120 are alternately arranged along the first direction. That is to say, the interdigital electrode 100 includes a first bus bar 110 and a second bus bar 120.
  • the first bus bar 110 is connected to a plurality of first finger bars 111 and a plurality of second false fingers alternately arranged along the first direction. 112.
  • the second bus bar 120 is connected to a plurality of first false fingers 121 and a plurality of second finger strips 122 that are alternately arranged along the first direction.
  • the first bus bar 110 and the second bus bar 120 are arranged oppositely, and one end of the first bus bar 110 is flush with one end of the second bus bar 120, and the other end of the first bus bar 110 is flush with the second bus bar 120. The other end of the bus bar 120 is flush.
  • the plurality of first finger strips 111 correspond to the plurality of first false fingers 121 one-to-one, the corresponding first finger strips 111 and the first false fingers 121 are located on the same straight line, and the first finger strips 111 and the first false fingers 121 There is a first gap between them, the plurality of second finger strips 122 correspond to the plurality of second false fingers 112 one by one, the corresponding second finger strips 122 and the second false fingers 112 are located on the same straight line, and the second finger strips There is a second gap between 122 and the second false finger 112 . There is a space between the adjacent first finger strips 111 and the second false fingers 112. As shown in Figure 6, the distance between the first finger strips 111 and the second false fingers 112 is P. Similarly, the first false finger The distance between 121 and the second finger 122 is also P. The distance P between the first finger 111 and the second false finger 112 can determine the resonant frequency of the surface acoustic wave resonator.
  • the finger aperture is a, multiple first finger apertures 111 and multiple second finger apertures 122 form multiple finger apertures, and at least some of the multiple finger apertures are finger apertures.
  • the existence of different finger apertures on the surface acoustic wave resonator can reduce the lateral resonance mode, thereby achieving the effect of the surface acoustic wave resonator suppressing the lateral resonance mode.
  • the first direction is the direction of the x-axis, that is, the first direction is perpendicular to the length direction of the first finger bar 111, and the length direction of the first finger bar 111 is the same as the direction of the y-axis.
  • the apertures of the plurality of finger strips formed by a plurality of adjacent first finger strips 111 and a plurality of second finger strips 122 alternately arranged along the first direction first increase and then decrease.
  • the trend may be a wave-like increasing or decreasing trend.
  • the finger apertures formed by a plurality of adjacent first finger strips 111 and a plurality of second finger strips 122 alternately arranged along the first direction show a trend of first increasing and then decreasing. That is to say, the apertures of multiple fingers arranged sequentially along the first direction first increase and then decrease to achieve weighting of the finger apertures.
  • the weighting of the finger apertures in the surface acoustic wave resonator can reduce the lateral Resonant mode, which reduces the resonance of the transverse mode.
  • the apertures of a plurality of finger strips arranged sequentially along the first direction show a trend of first increasing and then decreasing.
  • the trend of first increasing and then decreasing includes first increasing, then being flat and then decreasing.
  • the structure of the surface acoustic wave resonator in Figure 2 can also reduce the transverse resonance mode, that is, reduce the resonance of the transverse mode.
  • the apertures of multiple finger strips arranged sequentially along the first direction first increase, then decrease, then increase, and then decrease, that is, they show a wave-shaped increase and decrease trend.
  • This structure also achieves Without the weighting of the finger aperture, the weighting of the finger aperture in the surface acoustic wave resonator can reduce the transverse resonance mode, that is, the resonance of the transverse mode can be reduced.
  • the apertures of the plurality of finger strips arranged sequentially along the first direction also show a wave-shaped increasing and decreasing trend.
  • the embodiment of the present application realizes modulation of the finger aperture of the surface acoustic wave resonator by performing a fractal design on at least one of the first bus bar 110 and the second bus bar 120 , that is, by performing a fractal design on the first bus bar 110
  • a fractal design is performed on at least one of the second bus bars 120 to realize that the apertures of the plurality of finger bars arranged sequentially along the first direction first increase and then decrease, or have a wave-shaped increasing and decreasing trend.
  • the fractal design method for at least one of the first bus bar 110 and the second bus bar 120 is as follows: as shown in FIG. 1 , at least one of the first bus bar 110 and the second bus bar 120 has an n-order fractal structure,
  • the n-order fractal structure includes 2 n-1 first-order fractal structures 113 connected in sequence.
  • the first-order fractal structure 113 includes a connected first connecting bar 1131 and a second connecting bar 1132. One end of the first connecting bar 1131 is away from the second connecting bar 1132 and one end of the second connecting bar 1132 is away from the first connecting bar 1131.
  • connection line is located between the first bus bar 110 and the second bus bar 120 , that is to say, the opening of the area formed by the cooperation of the first connecting bar 1131 and the second connecting bar 1132 faces the first bus bar 110 and the second bus bar between 120.
  • the angle between the first connecting bar 1131 and the first straight line 1133 is the first deflection angle ⁇ 1
  • the angle between the second connecting bar 1132 and the first straight line 1133 is the second deflection angle ⁇ 2
  • the first straight line 1133 is perpendicular to the first finger bar 111, and the first deflection angle and the second deflection angle are both acute angles. That is to say, the first straight line 1133 is parallel to the direction of the x-axis.
  • the 2 n-1 first-order fractal structures 113 in the n-order fractal structure form 2 n-1 first deflection angles and 2 n-1 second deflection angles, that is to say, each first-order structure has a first deflection angle. angle and a second deflection angle, then 2 n- 1 first-order fractal structures 113 have 2 n-1 first deflection angles and 2 n-1 second deflection angles, and 2 n-1 first deflection angles
  • the angle range of at least part of the first deflection angles is 2°-16°
  • the angle range of at least part of the second deflection angles of the 2 n-1 second deflection angles is 2°-16°
  • the angle range is 2°-16°.
  • the setting of the first deflection angle of ° and the second deflection angle in the angle range of 2°-16° can deflect the sound wave propagation direction in the surface acoustic wave resonator to the arrangement direction of the first finger strips 111, thereby causing the surface acoustic wave to resonate.
  • the sound wave propagation direction in the device tends to the arrangement direction of the first finger bars 111, that is, the sound wave propagation direction in the surface acoustic wave resonator is close to the arrangement direction of the first finger bars 111, which is beneficial to reducing the lateral component of the sound wave.
  • the The fractal design of at least one of the first bus bar 110 and the second bus bar 120 can modulate the finger aperture of the surface acoustic wave resonator, which further reduces the lateral resonance mode, thereby realizing the surface acoustic wave resonator to suppress the lateral The effect of resonant modes.
  • the direction in which the first finger strips 111 are arranged is the same as the direction in which the x-axis is located.
  • the fractal design of at least one of the first bus bar 110 and the second bus bar 120 can form a plurality of first deflection angles in the angle range of 2°-16° and second deflection angles in the angle range of 2°-16°. angle to suppress the generation of the transverse component of the sound wave, thereby reducing the transverse component of the sound wave. It can also modulate the finger aperture of the surface acoustic wave resonator to suppress the resonance of the transverse mode and reduce the transverse resonance mode, thus making The surface acoustic wave resonator in the embodiment of the present application can better suppress the transverse resonant mode. It suppresses the transverse resonant mode in dual modes and can achieve better results.
  • the first bus bar 110 and the second bus bar 120 of the surface acoustic wave resonator in Figure 2 are both first-order fractal structures 113, which have a first deflection angle and a second deflection angle.
  • the angle range of the first deflection angle is 2°-16°
  • the angle range of the second deflection angle is 2°-16°
  • the apertures of the plurality of finger strips arranged sequentially along the first direction first increase and then decrease. trend.
  • the surface acoustic wave resonator in Figure 2 is tested and compared with the surface acoustic wave resonator whose transverse resonant mode is not suppressed.
  • the test comparison chart is shown in Figure 3.
  • the solid line part 1 in Figure 3 is the case where the transverse resonant mode is not suppressed.
  • the dotted line 2 shows the situation of the surface acoustic wave resonator in Figure 2. Among them, undulating peaks appear in the solid line part 1. These undulating peaks are transverse resonance modes. It can be seen from Figure 3 that the surface acoustic wave resonator in Figure 2 The wave resonator can better suppress the resonance of the transverse mode and reduce the transverse resonance mode, achieving the effect of the surface acoustic wave resonator in suppressing the transverse resonance mode.
  • the first bus bar 110 and the second bus bar 120 of the surface acoustic wave resonator in Figure 4 are both second-order fractal structures 114, which have two first deflection angles and two second deflection angles.
  • one of the first deflection angles has an angle range of 2°-16°
  • the other first deflection angle has an angle range of 0°
  • one of the second deflection angles has an angle range of 2°-16°
  • the other first deflection angle has an angle range of 2°-16°.
  • the angle range of the two deflection angles is 0°
  • the apertures of the plurality of finger strips arranged sequentially along the first direction show a trend of first increasing, then remaining flat, and then decreasing.
  • the surface acoustic wave resonator in Figure 4 is tested and compared with the surface acoustic wave resonator whose transverse resonant mode is not suppressed.
  • the test comparison chart is shown in Figure 5.
  • the solid line part 1 in Figure 5 is the case where the transverse resonant mode is not suppressed.
  • the dotted line 3 shows the situation of the surface acoustic wave resonator in Figure 4. Among them, undulating peaks appear in the solid line part 1. These undulating peaks are transverse resonance modes.
  • the acoustic surface wave resonator in Figure 5 can also better suppress the resonance of the transverse mode and reduce the transverse resonance mode, achieving the effect of the surface acoustic wave resonator in suppressing the transverse resonance mode.
  • both the first bus bar 110 and the second bus bar 120 of the surface acoustic wave resonator are second-order fractal structures 114, which have two first deflection angles and two second deflection angles. , and the angle range of the two first deflection angles is 2°-16°, and the angle range of the two second deflection angles is 2°-16°.
  • This structure does not have a flatly arranged finger strip aperture in the middle, so its Compared with the surface acoustic wave resonator in Figure 4, it can better suppress the resonance of the transverse mode and reduce the transverse resonance mode.
  • the first bus bar 110 and the second bus bar 120 of the surface acoustic wave resonator in Figure 6 are both third-order fractal structures 115, which have four first deflection angles and four second deflection angles.
  • the angle range of the four first deflection angles is 2°-16°
  • the angle range of the four second deflection angles is 2°-16°
  • the apertures of multiple finger strips arranged sequentially along the first direction are in the form of The trend of first increasing, then decreasing, then increasing, and then decreasing is a wave-shaped increasing and decreasing trend.
  • the surface acoustic wave resonator in Figure 6 is tested and compared with the surface acoustic wave resonator whose transverse resonant mode is not suppressed.
  • the test comparison chart is shown in Figure 7.
  • the solid line part 1 in Figure 7 is the case where the transverse resonant mode is not suppressed.
  • the dotted line 4 shows the situation of the surface acoustic wave resonator in Figure 6. Among them, undulating peaks appear in the solid line part 1. These undulating peaks are transverse resonance modes. It can be seen from Figure 7 that the acoustic surface wave resonator in Figure 7 The wave resonator can better suppress the resonance of the transverse mode and reduce the transverse resonance mode, achieving the effect of the surface acoustic wave resonator in suppressing the transverse resonance mode.
  • one of the first bus bar 110 and the second bus bar 120 has an n-order fractal structure, and the other has a linear structure.
  • the first bus bar 110 has a third-order fractal structure 115
  • the second bus bar 120 has a linear structure.
  • the first bus bar 110 has a first-order fractal structure 113 or a second-order fractal structure 114, etc.
  • the structure also has a plurality of first deflection angles ranging from 2° to 16° and a plurality of second deflection angles ranging from 2° to 16°, and a plurality of finger strip apertures arranged sequentially along the first direction.
  • first bus bar 110 and the second bus bar 120 is designed in a linear structure to facilitate the cascade connection of the two interdigital electrodes 100 .
  • the first bus bar 110 has an n-order fractal structure
  • the second bus bar 120 has a linear structure
  • the surface acoustic wave resonator includes two interdigital electrodes 100 in a cascade structure, and the two interdigital electrodes 100 share a A second bus bar 120
  • each of the two interdigital electrodes 100 includes a first bus bar 110
  • the first bus bars 110 of the two interdigital electrodes 100 are located on both sides of the second bus bar 120 .
  • the first bus bars 110 of the two interdigital electrodes 100 are located at both ends of the surface acoustic wave resonator along the length direction of the first finger bar 111, and the first bus bars 110 of the two interdigital electrodes 100 are arranged oppositely.
  • the two interdigital electrodes 100 share a second bus bar 120 .
  • the first bus bar and the second bus bar are n-order fractal structures, and multiple connecting bars of the first bus bar and the second bus bar are correspondingly parallel to each other.
  • the first bus bar 110 and the second bus bar 120 are both three-order fractal structures 115.
  • the first bus bar 110 and the second bus bar 120 are both connected by eight bus bars.
  • the eight bus bars of 110 are parallel to the eight bus bars of the second bus bar 120 from left to right.
  • This structure also has a plurality of first deflection angles ranging from 2° to 16°, a plurality of second deflection angles ranging from 2° to 16°, and a plurality of finger apertures arranged sequentially along the first direction.
  • the first bus bar 110 and the second bus bar 120 may both be a first-order fractal structure 113 or a second-order fractal structure 114 or the like.
  • the design of the first bus bar 110 and the second bus bar 120 as an n-order fractal structure also facilitates the cascade connection of the two interdigital electrodes 100 .
  • the surface acoustic wave resonator includes two interdigital electrodes 100 in a cascade structure.
  • the two interdigital electrodes 100 share a second bus bar 120, and each of the two interdigital electrodes 100 includes a first bus bar.
  • the first bus bar 110 of the two interdigital electrodes 100 is located on both sides of the second bus bar 120 .
  • the first bus bars 110 of the two interdigital electrodes 100 are located at both ends of the surface acoustic wave resonator along the length direction of the first finger bar 111, and the first bus bars 110 of the two interdigital electrodes 100 are arranged oppositely.
  • the two interdigital electrodes 100 share a second bus bar 120, and the plurality of connection bars of the first bus bar 110 and the second bus bar 120 of the two interdigital electrodes 100 are parallel to each other.
  • This structure can also better suppress the resonance of the transverse mode, reduce the transverse resonance mode, and achieve the effect of suppressing the transverse resonance mode of the surface acoustic wave resonator.
  • the first bus bar 110 is a first-order fractal structure 113
  • the second bus bar 120 is a linear structure
  • the surface acoustic wave resonator includes a cascade structure.
  • the first bus bar 110 is a third-order fractal structure 115
  • the second bus bar 120 is a linear structure
  • the surface acoustic wave resonator includes two interdigital electrodes 100 in a cascade structure.
  • the two interdigital electrodes 100 share a second bus bar 120.
  • the two interdigital electrodes 100 each include a first bus bar 110, and the first bus bars 110 of the two interdigital electrodes 100 are located on both sides of the second bus bar 120. side.
  • both the first bus bar 110 and the second bus bar 120 are n-order fractal structures.
  • the first bus bar 110 and the second bus bar 120 are symmetrical along the first center line, and the first center line is vertical. on the first finger strip 111 and passes through the center of the interdigital electrode 100 . This structure makes the structure of the surface acoustic wave resonator more regular.
  • the lengths of each first false finger 121 are the same, the lengths of at least some of the first finger strips 111 among the plurality of first finger strips 111 are unequal, and the lengths of each second false finger 112 are the same. At least some of the second finger strips 112 have different lengths. That is, the finger aperture is changed by changing the length of the first finger bar 111 and the length of the second finger bar 122, wherein the distance between the first gap and the second gap remains unchanged.
  • the surface acoustic wave resonator further includes two reflection gratings 200 .
  • the two reflection gratings 200 are along the direction perpendicular to the first finger bar 111 (that is, the direction of the x-axis) or along the first bus bar 110
  • the extension direction is set at both ends of the interdigital electrode 100, and there is a space between the two reflection gratings 200 and the interdigital electrode 100.
  • the two reflection gratings 200 are used to transmit the acoustic wave signal leaked to both ends of the interdigital electrode 100. Reflected back to the interdigital electrode 100.
  • the reflection grating 200 includes a third bus bar and a fourth bus bar disposed oppositely and a grid disposed between the third bus bar and the fourth bus bar.
  • the number of interdigital electrodes 100 is multiple, and the plurality of interdigital electrodes 100 are arranged in series in a direction perpendicular to the first finger strip 111 (that is, the direction of the x-axis).
  • Two reflective The grid 200 is disposed at both ends of a plurality of interdigital electrodes 100 connected in series along a direction perpendicular to the first finger bar 111 (that is, the direction of the x-axis), and the two reflection grids 200 are connected to a plurality of interdigital electrodes connected in series. There is space between 100 and 100.
  • the number of the interdigital electrodes 100 is two.
  • the two interdigital electrodes 100 are arranged in series.
  • the two reflection gratings 200 are arranged on two electrodes in a direction perpendicular to the first finger bar 111 . There are gaps at both ends of the series-connected interdigital electrodes 100 and between the two reflection gratings 200 and the two series-connected interdigital electrodes 100 .
  • Embodiments of the present application also provide a surface acoustic wave filter.
  • the surface acoustic wave filter includes a support substrate, a temperature compensation layer and a piezoelectric substrate that are stacked in sequence, and an acoustic surface provided on the piezoelectric substrate.
  • Wave resonator that is to say, the surface acoustic wave filter provided by the embodiment of the present application includes a support substrate, a temperature compensation layer, a piezoelectric substrate, and a surface acoustic wave resonator disposed on the piezoelectric substrate.
  • the surface acoustic wave resonator is a surface acoustic wave resonator of any of the above solutions
  • the piezoelectric substrate is a material with piezoelectric effect
  • the temperature coefficient of the temperature compensation layer is opposite to the temperature coefficient of the piezoelectric substrate.
  • the piezoelectric substrate is a lithium tantalate substrate.

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Abstract

本申请提供一种声表面波谐振器及声表面波滤波器，该声表面波谐振器包括叉指电极，叉指电极包括相对设置的第一汇流条和第二汇流条，第一汇流条连接有沿第一方向交替排布的多个第一指条和多个第二假指；第二汇流条连接有沿第一方向交替排布的多个第一假指和多个第二指条；多个第一指条与多个第一假指一一对应；多个第二指条与多个第二假指一一对应；在任意相邻的第一指条和第二指条中，第一指条远离第一汇流条的一端与第二指条远离第二汇流条的一端之间的间距为指条孔径，多个相邻的第一指条和第二指条形成多个指条孔径，在多个指条孔径中至少部分指条孔径不同。该声表面波谐振器能够减小横向谐振模，达到抑制横向谐振模的效果。

Description

声表面波谐振器及声表面波滤波器
本申请要求于2022年4月8日提交中国专利局、申请号为202210367887.2、申请名称为“声表面波谐振器及声表面波滤波器”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请实施例涉及声表面波滤波器技术领域，尤其涉及一种声表面波谐振器及声表面波滤波器。
背景技术
声表面波滤波器是利用压电效应和声表面波传播的物理特性制成的一种无源带通滤波器。其作用是对电信号进行滤波、延时等处理。它具有体积小、性能稳定、过载能力强、相位失真小、无需调整等优点，广泛应用于电视机、录像机、无线数据传输***等领域中。
声表面波滤波器包括依次层叠设置的支撑衬底、温度补偿层和压电衬底，以及设置于压电衬底上的声表面波谐振器。声表面波谐振器的主要作用原理是利用压电衬底的压电特性，向声表面波谐振器输入电信号，输入的电信号在声表面波谐振器内完成电信号-声波信号-电信号的转换，以达到过滤不必要的讯号及杂讯，提升收讯品质的目标。在相关技术中，为了降低声表面波谐振器的温度系数，通常在压电衬底下沉积一层和压电衬底温度系数相反的温度补偿层，为了使声表面波谐振器达到良好的温度补偿效果，需要对压电衬底进行减薄。
然而，当压电衬底的厚度与在声表面波谐振器中传播的声波波长λ接近(即压电衬底的厚度小于10λ)时，声表面波谐振器会产生横向谐振模，横向谐振模会导致声表面波滤波器的通带中出现尖锐的传输零点，进而降低声表面波滤波器的性能。
发明内容
本申请提实施例供一种声表面波谐振器及声表面波滤波器，用以解决声表面波谐振器会产生横向谐振模的技术问题。
本申请实施例为解决上述技术问题提供如下技术方案：
本申请实施例提供了一种声表面波谐振器，包括叉指电极，所述叉指电 极包括相对设置的第一汇流条和第二汇流条，所述第一汇流条连接有沿第一方向交替排布的多个第一指条和多个第二假指；所述第二汇流条连接有沿第一方向交替排布的多个第一假指和多个第二指条；
多个所述第一指条与多个所述第一假指一一对应，相对应的所述第一指条与所述第一假指位于同一直线上，且所述第一指条和所述第一假指之间具有第一间隙；
多个所述第二指条与多个所述第二假指一一对应，相对应的所述第二指条与所述第二假指位于同一直线上，且所述第二指条和所述第二假指之间具有第二间隙；
在任意相邻的所述第一指条和所述第二指条中，所述第一指条远离所述第一汇流条的一端与所述第二指条远离所述第二汇流条的一端之间的间距为指条孔径，多个所述第一指条和多个所述第二指条形成多个所述指条孔径，且多个所述指条孔径中至少部分所述指条孔径不相等。
本申请实施例的有益效果是：本申请实施例的声表面波谐振器通过改变叉指电极中的至少部分指条孔径，以使多个所述指条孔径中至少部分指条孔径不同，声表面波谐振器上不同的指条孔径的存在能够减小横向谐振模，从而实现声表面波谐振器抑制横向谐振模的效果。
在一种可能的实施方式中，所述第一方向与所述第一指条的长度方向垂直，沿第一方向交替排布的多个所述第一指条和多个所述第二指条形成的多个所述指条孔径呈先增大后减小的趋势或呈波浪形增减趋势。
在一种可能的实施方式中，所述第一汇流条和所述第二汇流条中的至少一个为n阶分形结构，所述n阶分形结构包括依次连接的2 n-1个一阶分形结构，n为正整数；
所述一阶分形结构包括相连接的第一连接条和第二连接条，所述第一连接条远离所述第二连接条的一端和所述第二连接条远离所述第一连接条的一端的连线位于所述第一汇流条和所述第二汇流条之间；
所述第一连接条与第一直线的夹角为第一偏向角，所述第二连接条与所述第一直线的夹角为第二偏向角，所述第一直线垂直于所述第一指条，所述第一偏向角和所述第二偏向角均为锐角；
所述n阶分形结构中的2 n-1个一阶分形结构形成2 n-1个第一偏向角和2 n-1 个第二偏向角，2 n-1个所述第一偏向角中至少部分所述第一偏向角的角度范围为2°-16°，2 n-1个所述第二偏向角中至少部分所述第二偏向角的角度范围为2°-16°。
在一种可能的实施方式中，所述第一汇流条和所述第二汇流条中的一个为所述n阶分形结构，另一个为直线型结构。
在一种可能的实施方式中，所述第一汇流条为所述n阶分形结构，所述第二汇流条为所述直线型结构；
所述声表面波谐振器包括呈级联结构的两个所述叉指电极，两个所述叉指电极共用一个第二汇流条，两个所述叉指电极各包括一个所述第一汇流条，且两个所述叉指电极的所述第一汇流条位于所述第二汇流条的两侧。
在一种可能的实施方式中，所述第一汇流条和所述第二汇流条均为n阶分形结构，所述第一汇流条和所述第二汇流条沿第一中心线对称，所述第一中心线垂直于所述第一指条且经过所述叉指电极的中心。
在一种可能的实施方式中，所述第一汇流条和所述第二汇流条均为所述n阶分形结构，所述第一汇流条和所述第二汇流条的多个连接条相互对应平行。
在一种可能的实施方式中，各所述第一假指的长度相同，多个所述第一指条中至少部分所述第一指条的长度不相等；
各所述第二假指的长度相同，多个所述第二指条中至少部分所述第二指条的长度不相等。
在一种可能的实施方式中，还包括两个反射栅，两个所述反射栅沿垂直于所述第一指条的方向设置于所述叉指电极的两端，且两个所述反射栅与所述叉指电极之间均具有间隔空间，两个所述反射栅用于将泄露到叉指电极的两端的声波信号反射回所述叉指电极。
在一种可能的实施方式中，所述叉指电极的数量为多个，多个所述叉指电极沿垂直于所述第一指条的方向依次串联设置，两个所述反射栅沿垂直于所述第一指条的方向设置于多个依次串联的叉指电极的两端，且两个所述反射栅与多个依次串联的叉指电极之间均具有间隔空间。
本申请实施例还提供了一种声表面波滤波器，该声表面波滤波器包括依次层叠设置的支撑衬底、温度补偿层和压电衬底，以及设置于所述压电衬底 上的声表面波谐振器，所述声表面波谐振器为上述任一方案所述的声表面波谐振器。
本申请实施例的声表面波滤波器的有益效果与上述声表面波谐振器的有益效果相同，在此不再赘述。
除了上面所描述的本申请解决的技术问题、构成技术方案的技术特征以及由这些技术方案的技术特征所带来的有益效果外，本申请提供的声表面波谐振器及声表面波滤波器所能解决的其他技术问题、技术方案中包含的其他技术特征以及这些技术特征带来的有益效果，将在具体实施方式中作出进一步详细的说明。
附图说明
为了更清楚地说明本申请实施例或现有技术中的技术方案，下面将对本申请实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本申请的一部分实施例，这些附图和文字描述并不是为了通过任何方式限制本申请构思的范围，而是通过参考特定实施例为本领域技术人员说明本申请的概念，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其它的附图。
图1为本申请实施例中声表面波谐振器的第一汇流条和第二汇流条的几种结构示意图；
图2为本申请实施例中声表面波谐振器的一种结构示意图；
图3为图2中的声表面波谐振器与横向谐振模未抑制的声表面波谐振器的测试对比图；
图4为本申请实施例中声表面波谐振器的另一种结构示意图；
图5为图4中的声表面波谐振器与横向谐振模未抑制的声表面波谐振器的测试对比图；
图6为本申请实施例中声表面波谐振器的另一种结构示意图；
图7为图6中的声表面波谐振器与横向谐振模未抑制的声表面波谐振器的测试对比图；
图8为本申请实施例中声表面波谐振器的另一种结构示意图；
图9为两个叉指电极呈级联结构的声表面波谐振器的一种结构示意图；
图10为两个叉指电极呈级联结构的声表面波谐振器的另一种结构示意 图；
图11为两个叉指电极串联形成的声表面波谐振器的一种结构示意图；
图12为本申请实施例中声表面波谐振器的另一种结构示意图；
图13为两个叉指电极呈级联结构的声表面波谐振器的另一种结构示意图。
附图标记说明：
100、叉指电极；
110、第一汇流条；120、第二汇流条；
111、第一指条；112、第二假指；113、一阶分形结构；114、二阶分形结构；115、三阶分形结构；
1131、第一连接条；1132、第二连接条；1133、第一直线；
121、第一假指；122、第二指条；
200、反射栅。
通过上述附图，已示出本申请明确的实施例，后文中将有更详细的描述。这些附图和文字描述并不是为了通过任何方式限制本申请构思的范围，而是通过参考特定实施例为本领域技术人员说明本申请的概念。
具体实施方式
在相关技术中，为了降低声表面波谐振器的温度系数，通常在压电衬底下沉积一层和压电衬底温度系数相反的温度补偿层，为了使声表面波谐振器达到良好的温度补偿效果，需要对压电衬底进行减薄。然而，当压电衬底的厚度与在声表面波谐振器中传播的声波波长λ接近(即压电衬底的厚度小于10λ)时，声表面波谐振器会激发出更加复杂的声波模式，使得声表面波谐振器内的声波传播方向与声表面波谐振器的指条排列方向产生较大的偏角，即声波不再仅沿着指条排列方向传播，而是产生一个横向分量，这个横向分量在不加干扰的情况下会产生横向谐振模，横向谐振模在声表面波谐振器的正反谐振峰之间有明显的幅度，靠近正反谐振峰的横向谐振模会导致声表面波滤波器的通带中出现尖锐的传输零点，进而降低声表面波滤波器的性能。
有鉴于此，本申请实施例通过改变叉指电极中的至少部分指条孔径，以使多个所述指条孔径中至少部分指条孔径不同，声表面波谐振器上不同 的指条孔径的存在能够减小横向谐振模，从而实现声表面波谐振器抑制横向谐振模的效果。
本申请所描述的实施例仅仅是本申请的一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
图1为本申请实施例中声表面波谐振器的第一汇流条和第二汇流条的几种结构示意图；图2为本申请实施例中声表面波谐振器的一种结构示意图；图3为图2中的声表面波谐振器与横向谐振模未抑制的声表面波谐振器的测试对比图；图4为本申请实施例中声表面波谐振器的另一种结构示意图；图5为图4中的声表面波谐振器与横向谐振模未抑制的声表面波谐振器的测试对比图；图6为本申请实施例中声表面波谐振器的另一种结构示意图；图7为图6中的声表面波谐振器与横向谐振模未抑制的声表面波谐振器的测试对比图；图8为本申请实施例中声表面波谐振器的另一种结构示意图；图9为两个叉指电极呈级联结构的声表面波谐振器的一种结构示意图；图10为两个叉指电极呈级联结构的声表面波谐振器的另一种结构示意图；图11为两个叉指电极串联形成的声表面波谐振器的一种结构示意图。
如图2、图4、图6、图8和图12所示，本申请实施例提供的声表面波谐振器包括叉指电极100，叉指电极100包括第一汇流条110、连接于第一汇流条110上的多个第一指条111和多个第二假指112、第二汇流条120、连接于第二汇流条120上的多个第一假指121和多个第二指条122，多个第一指条111和多个第二假指112在第一汇流条110上沿第一方向交替排布，多个第一假指121和多个第二指条122在第二汇流条120沿第一方向上交替排布。也就是说，叉指电极100包括第一汇流条110和第二汇流条120，第一汇流条110连接有沿第一方向交替排布的多个第一指条111和多个第二假指112，第二汇流条120连接有沿第一方向交替排布的多个第一假指121和多个第二指条122。
第一汇流条110与第二汇流条120相对设置，且第一汇流条110的一个端部与第二汇流条120的一个端部平齐，第一汇流条110的另一个端部与第二汇流条120的另一个端部平齐。多个第一指条111与多个第一假指121一一对应，相对应的第一指条111与第一假指121位于同一直线上， 且第一指条111和第一假指121之间具有第一间隙，多个第二指条122与多个第二假指112一一对应，相对应的第二指条122与第二假指112位于同一直线上，且第二指条122和第二假指112之间具有第二间隙。相邻的第一指条111和第二假指112之间具有间隔空间，如图6所示，第一指条111和第二假指112之间的距离为P，同样，第一假指121和第二指条122之间的距离也为P，第一指条111和第二假指112之间的距离P能够决定声表面波谐振器的谐振频率。
在任意相邻的第一指条111和第二指条122中，第一指条111远离第一汇流条110的一端与第二指条122远离第二汇流条120的一端之间的间距为指条孔径，如图6所示，指条孔径为a，多个第一指条111和多个第二指条122形成多个指条孔径，且多个指条孔径中至少部分指条孔径不相等，声表面波谐振器上不同的指条孔径的存在能够减小横向谐振模，从而实现声表面波谐振器抑制横向谐振模的效果。
可以理解的是，第一方向为x轴所在的方向，即第一方向与第一指条111的长度方向垂直，第一指条111的长度方向与y轴所在的方向相同。
在本申请的一些实施例中，沿第一方向交替排布的多个相邻的第一指条111和多个第二指条122形成的多个指条孔径呈先增大后减小的趋势或呈波浪形增减趋势。如图2所示，沿第一方向交替排布的多个相邻的第一指条111和多个第二指条122形成的多个指条孔径呈先增大后减小的趋势，也就是说，多个沿第一方向依次排列的多个指条孔径呈先增大后减小的趋势，以实现指条孔径的加权，声表面波谐振器内存在指条孔径加权能够减小横向谐振模，即减小横向模的谐振。如图4所示，多个沿第一方向依次排列的多个指条孔径呈先增大后减小的趋势，其中，先增大后减小的趋势包含先增大后持平然后减小的情形，也就是说包含图2中展示的情况，图2中的声表面波谐振器的结构同样能够减小横向谐振模，即减小横向模的谐振。如图6所示，多个沿第一方向依次排列的多个指条孔径呈先增大后减小，再增大，再减小的趋势，即呈波浪形增减趋势，该结构同样实现了指条孔径的加权，声表面波谐振器内存在指条孔径加权即能够减小横向谐振模，即减小横向模的谐振。如图12所示，多个沿第一方向依次排列的多个指条孔径同样呈波浪形增减趋势。
本申请实施例通过对第一汇流条110和第二汇流条120中的至少一个进行分形设计来实现对声表面波谐振器的指条孔径进行调制，也就是说，通过对第一汇流条110和第二汇流条120中的至少一个进行分形设计来实现多个沿第一方向依次排列的多个指条孔径呈先增大后减小的趋势或呈波浪形增减趋势。
对第一汇流条110和第二汇流条120中的至少一个进行分形设计的方式为：如图1所示，第一汇流条110和第二汇流条120中的至少一个为n阶分形结构，n阶分形结构包括依次连接的2 n-1个一阶分形结构113。其中，一阶分形结构113包括相连接的第一连接条1131和第二连接条1132，第一连接条1131远离第二连接条1132的一端和第二连接条1132远离第一连接条1131的一端的连线位于第一汇流条110和第二汇流条120之间，也就是说，第一连接条1131和第二连接条1132配合形成的区域的开口朝向第一汇流条110和第二汇流条120之间。第一连接条1131与第一直线1133的夹角为第一偏向角θ 1，第二连接条1132与第一直线1133的夹角为第二偏向角θ 2，其中，第一直线1133垂直于第一指条111，第一偏向角和第二偏向角均为锐角，也就是说，第一直线1133与x轴所在的方向平行。n阶分形结构中的2 n-1个一阶分形结构113形成2 n-1个第一偏向角和2 n-1个第二偏向角，也就是说每个一阶结构具有一个第一偏向角和一个第二偏向角，那么2 n-1个一阶分形结构113就具有2 n-1个第一偏向角和2 n-1个第二偏向角，2 n-1个第一偏向角中至少部分第一偏向角的角度范围为2°-16°，2 n-1个第二偏向角中至少部分第二偏向角的角度范围为2°-16°，角度范围为2°-16°的第一偏向角和角度范围为2°-16°的第二偏向角的设置能够使得声表面波谐振器内声波传播方向偏转向第一指条111的排列方向，进而使得声表面波谐振器内声波传播方向趋向于第一指条111的排列方向，即声表面波谐振器内声波传播方向与第一指条111的排列方向接近，进而有利于减小声波的横向分量，同时，对第一汇流条110和第二汇流条120中的至少一个进行分形设计能够对声表面波谐振器的指条孔径进行调制，这进一步减小了横向谐振模，从而实现声表面波谐振器抑制横向谐振模的效果。
值得说明的是，第一指条111排列的方向与x轴所在的方向相同。
对第一汇流条110和第二汇流条120中的至少一个进行分形设计既能够形成多个角度范围为2°-16°的第一偏向角和角度范围为2°-16°的第二偏向角，以抑制声波的横向分量的产生，从而减小声波的横向分量，又能够对声表面波谐振器的指条孔径进行调制，以抑制横向模的谐振，减小了横向谐振模，从而使得本申请实施例的声表面波谐振器能够较好的抑制横向谐振模，其以双重模式抑制横向谐振模，能够达到较好的效果。
如图2所示，图2中的声表面波谐振器的第一汇流条110和第二汇流条120均为一阶分形结构113，其具有一个第一偏向角和一个第二偏向角，第一偏向角的角度范围为2°-16°，第二偏向角的角度范围为2°-16°，且多个沿第一方向依次排列的多个指条孔径呈先增大后减小的趋势。图2中的声表面波谐振器与横向谐振模未抑制的声表面波谐振器进行测试对比，测试对比图如图3所示，图3中实线部分1为横向谐振模未抑制的情况，虚线2为图2中的声表面波谐振器展现的情况，其中，实线部分1中出现起伏的峰，这些起伏的峰为横向谐振模，由图3可以看出，图2中的声表面波谐振器能够较好的抑制横向模的谐振，减小了横向谐振模，达到了声表面波谐振器抑制横向谐振模的效果。
如图4所示，图4中的声表面波谐振器的第一汇流条110和第二汇流条120均为二阶分形结构114，其具有两个第一偏向角和两个第二偏向角，且其中一个第一偏向角的角度范围为2°-16°，另一个第一偏向角的角度范围为0°，其中一个第二偏向角的角度范围为2°-16°，另一个第二偏向角的角度范围为0°，且多个沿第一方向依次排列的多个指条孔径呈先增大后持平再减小的趋势。图4中的声表面波谐振器与横向谐振模未抑制的声表面波谐振器进行测试对比，测试对比图如图5所示，图5中实线部分1为横向谐振模未抑制的情况，虚线3为图4中的声表面波谐振器展现的情况，其中，实线部分1中出现起伏的峰，这些起伏的峰为横向谐振模，由图5可以看出，图5中的声表面波谐振器同样能够较好的抑制横向模的谐振，减小了横向谐振模，达到了声表面波谐振器抑制横向谐振模的效果。
在本申请的一些可能实施例中，声表面波谐振器的第一汇流条110和第二汇流条120均为二阶分形结构114，其具有两个第一偏向角和两个第二偏向角，且两个第一偏向角的角度范围为2°-16°，两个第二偏向角的 角度范围为2°-16°，此结构由于其中部不在具有持平排列的指条孔径，故其相较于图4中的声表面波谐振器能够更好的抑制横向模的谐振，减小了横向谐振模。
如图6所示，图6中的声表面波谐振器的第一汇流条110和第二汇流条120均为三阶分形结构115，其具有四个第一偏向角和四个第二偏向角，且四个第一偏向角的角度范围为2°-16°，四个第二偏向角的角度范围为2°-16°，且多个沿第一方向依次排列的多个指条孔径呈先增大后减小，再增大，再减小的趋势，即呈波浪形增减趋势。图6中的声表面波谐振器与横向谐振模未抑制的声表面波谐振器进行测试对比，测试对比图如图7所示，图7中实线部分1为横向谐振模未抑制的情况，虚线4为图6中的声表面波谐振器展现的情况，其中，实线部分1中出现起伏的峰，这些起伏的峰为横向谐振模，由图7可以看出，图7中的声表面波谐振器能够较好的抑制横向模的谐振，减小了横向谐振模，达到了声表面波谐振器抑制横向谐振模的效果。
在本申请的一些可能的实施例中，第一汇流条110和第二汇流条120中的一个为n阶分形结构，另一个为直线型结构。如图8所示，第一汇流条110为三阶分形结构115，第二汇流条120为直线型结构，当然，第一汇流条110为一阶分形结构113或者二阶分形结构114等，此结构同样具有多个角度范围为2°-16°的第一偏向角和多个角度范围为2°-16°的第二偏向角，以及多个沿第一方向依次排列的指条孔径呈先增大后减小，再增大，再减小的趋势，即呈波浪形增减趋势。此结构同样能够较好的抑制横向模的谐振，减小了横向谐振模，达到了声表面波谐振器抑制横向谐振模的效果。并且，第一汇流条110和第二汇流条120中的一个为直线型结构的设计方式便于两个叉指电极100的级联。示例性的，第一汇流条110为n阶分形结构，第二汇流条120为直线型结构，声表面波谐振器包括呈级联结构的两个叉指电极100，两个叉指电极100共用一个第二汇流条120，两个叉指电极100各包括一个第一汇流条110，且两个叉指电极100的第一汇流110条位于第二汇流条120的两侧。也就是说，两个叉指电极100的第一汇流条110位于声表面波谐振器沿第一指条111的长度方向的两端，两个叉指电极100的第一汇流条110相对设置，两个叉指电极100共用一个 第二汇流条120。
在本申请的一些实施例中，第一汇流条和第二汇流条为n阶分形结构，第一汇流条和第二汇流条的多个连接条相互对应平行。如图12所示，第一汇流条110和第二汇流条120均为三阶分形结构115，第一汇流条110和第二汇流条120均为八个汇流条连接而成，第一汇流条110的八个汇流条与第二汇流条120的八个汇流条从左往右依次对应平行。此结构同样具有多个角度范围为2°-16°的第一偏向角和多个角度范围为2°-16°的第二偏向角，以及多个沿第一方向依次排列的指条孔径呈波浪形增减趋势。同样地，第一汇流条110和第二汇流条120也可以均为一阶分形结构113或者二阶分形结构114等。第一汇流条110和第二汇流条120为n阶分形结构的设计方式同样便于两个叉指电极100的级联。如图13所示，声表面波谐振器包括呈级联结构的两个叉指电极100，两个叉指电极100共用一个第二汇流条120，两个叉指电极100各包括一个第一汇流条110，且两个叉指电极100的第一汇流110条位于第二汇流条120的两侧。也就是说，两个叉指电极100的第一汇流条110位于声表面波谐振器沿第一指条111的长度方向的两端，两个叉指电极100的第一汇流条110相对设置，两个叉指电极100共用一个第二汇流条120，两个叉指电极100的第一汇流条110以及第二汇流条120的多个连接条相互平行。此结构也能够较好地抑制横向模的谐振，减小了横向谐振模，达到了声表面波谐振器抑制横向谐振模的效果。
在本申请的一些实施例中，示例性的，如图9所示，第一汇流条110为一阶分形结构113，第二汇流条120为直线型结构，声表面波谐振器包括呈级联结构的两个叉指电极100，两个叉指电极100共用一个第二汇流条120，两个叉指电极100各包括一个第一汇流条110，且两个叉指电极100的第一汇流110条位于第二汇流条120的两侧。示例性的，如图10所示，第一汇流条110为三阶分形结构115，第二汇流条120为直线型结构，声表面波谐振器包括呈级联结构的两个叉指电极100，两个叉指电极100共用一个第二汇流条120，两个叉指电极100各包括一个第一汇流条110，且两个叉指电极100的第一汇流110条位于第二汇流条120的两侧。
在本申请的一些实施例中，第一汇流条110和第二汇流条120均为n 阶分形结构，第一汇流条110和第二汇流条120沿第一中心线对称，第一中心线垂直于第一指条111且经过叉指电极100的中心。此结构使得声表面波谐振器的结构更加规整。
在本申请的一些实施例中，各第一假指121的长度相同，多个第一指条111中至少部分第一指条111的长度不相等，各第二假指112的长度相同，多个第二指条112中至少部分第二指条112的长度不同。也就是说，通过改变第一指条111的长度和第二指条122的长度来改变指条孔径，其中第一间隙和第二间隙的距离不变。
在本申请实施例中，声表面波谐振器还包括两个反射栅200，两个反射栅200沿垂直于第一指条111的方向(即x轴所在的方向)或者沿第一汇流条110的延伸方向设置于叉指电极100的两端，且两个反射栅200与叉指电极100之间均具有间隔空间，两个反射栅200用于将泄露到叉指电极100的两端的声波信号反射回叉指电极100。
可选的，反射栅200包括相对设置的第三汇流条和第四汇流条以及设置于第三汇流条和第四汇流条之间的栅极。
在本申请的一些实施例中，叉指电极100的数量为多个，多个叉指电极100沿垂直于第一指条111的方向(即x轴所在的方向)依次串联设置，两个反射栅200沿垂直于第一指条111的方向(即x轴所在的方向)设置于多个依次串联的叉指电极100的两端，且两个反射栅200与多个依次串联的叉指电极100之间均具有间隔空间。示例性的，如图11所示，叉指电极100的数量为两个，两个叉指电极100依次串联设置，两个反射栅200沿垂直于第一指条111的方向设置于两个依次串联的叉指电极100的两端，且两个反射栅200与两个依次串联的叉指电极100之间均具有间隔空间。
本申请实施例还提供了一种声表面波滤波器，该声表面波滤波器包括依次层叠设置的支撑衬底、温度补偿层和压电衬底，以及设置于压电衬底上的声表面波谐振器，也就是说，本申请实施例提供的声表面波滤波器包括支撑衬底、温度补偿层、压电衬底以及设置于压电衬底上的声表面波谐振器。其中，声表面波谐振器为上述任一方案的声表面波谐振器，压电衬底为压电效应的材料，温度补偿层的温度系数与压电衬底温度系数相反。可选的，压电衬底为钽酸锂衬底。
本领域技术人员在考虑说明书及实践这里公开的发明后，将容易想到本申请的其它实施方案。本申请旨在涵盖本申请的任何变型、用途或者适应性变化，这些变型、用途或者适应性变化遵循本申请的一般性原理并包括本申请未公开的本技术领域中的公知常识或惯用技术手段。说明书和实施例仅被视为示例性的，本申请的真正范围和精神由下面的权利要求书指出。
应当理解的是，本申请并不局限于上面已经描述并在附图中示出的精确结构，并且可以在不脱离其范围进行各种修改和改变。本申请的范围仅由所附的权利要求书来限制。

Claims (11)

  1. 一种声表面波谐振器，其特征在于，包括叉指电极，所述叉指电极包括相对设置的第一汇流条和第二汇流条，所述第一汇流条连接有沿第一方向交替排布的多个第一指条和多个第二假指；所述第二汇流条连接有沿所述第一方向交替排布的多个第一假指和多个第二指条；
    多个所述第一指条与多个所述第一假指一一对应，相对应的所述第一指条与所述第一假指位于同一直线上，且所述第一指条和所述第一假指之间具有第一间隙；
    多个所述第二指条与多个所述第二假指一一对应，相对应的所述第二指条与所述第二假指位于同一直线上，且所述第二指条和所述第二假指之间具有第二间隙；
    在任意相邻的所述第一指条和所述第二指条中，所述第一指条远离所述第一汇流条的一端与所述第二指条远离所述第二汇流条的一端之间的间距为指条孔径，多个所述第一指条和多个所述第二指条形成多个所述指条孔径，且多个所述指条孔径中至少部分所述指条孔径不相等。
  2. 根据权利要求1所述的声表面波谐振器，其特征在于，所述第一方向与所述第一指条的长度方向垂直，沿所述第一方向交替排布的多个所述第一指条和多个所述第二指条形成的多个所述指条孔径呈先增大后减小的趋势或呈波浪形增减趋势。
  3. 根据权利要求2所述的声表面波谐振器，其特征在于，所述第一汇流条和所述第二汇流条中的至少一个为n阶分形结构，所述n阶分形结构包括2 n-1个一阶分形结构依次连接形成，n为正整数；
    所述一阶分形结构包括相连接的第一连接条和第二连接条，所述第一连接条远离所述第二连接条的一端和所述第二连接条远离所述第一连接条的一端的连线位于所述第一汇流条和所述第二汇流条之间；
    所述第一连接条与第一直线的夹角为第一偏向角，所述第二连接条与所述第一直线的夹角为第二偏向角，所述第一直线垂直于所述第一指条，所述第一偏向角和所述第二偏向角均为锐角；
    所述n阶分形结构中的2 n-1个一阶分形结构形成2 n-1个第一偏向角和2 n-1个第二偏向角，2 n-1个所述第一偏向角中至少部分所述第一偏向角的角度范围 为2°-16°，2 n-1个所述第二偏向角中至少部分所述第二偏向角的角度范围为2°-16°。
  4. 根据权利要求3所述的声表面波谐振器，其特征在于，所述第一汇流条和所述第二汇流条中的一个为所述n阶分形结构，另一个为直线型结构。
  5. 根据权利要求4所述的声表面波谐振器，其特征在于，所述第一汇流条为所述n阶分形结构，所述第二汇流条为所述直线型结构；
    所述声表面波谐振器包括呈级联结构的两个所述叉指电极，两个所述叉指电极共用一个第二汇流条，两个所述叉指电极各包括一个所述第一汇流条，且两个所述叉指电极的所述第一汇流条位于所述第二汇流条的两侧。
  6. 根据权利要求3所述的声表面波谐振器，其特征在于，所述第一汇流条和所述第二汇流条均为所述n阶分形结构，所述第一汇流条和所述第二汇流条沿第一中心线对称，所述第一中心线垂直于所述第一指条且经过所述叉指电极的中心。
  7. 根据权利要求3所述的声表面波谐振器，其特征在于，所述第一汇流条和所述第二汇流条均为所述n阶分形结构，所述第一汇流条和所述第二汇流条的多个连接条相互对应平行。
  8. 根据权利要求1所述的声表面波谐振器，其特征在于，各所述第一假指的长度相同，多个所述第一指条中至少部分所述第一指条的长度不相等；
    各所述第二假指的长度相同，多个所述第二指条中至少部分所述第二指条的长度不相等。
  9. 根据权利要求1所述的声表面波谐振器，其特征在于，还包括两个反射栅，两个所述反射栅沿垂直于所述第一指条的方向设置于所述叉指电极的两端，且两个所述反射栅与所述叉指电极之间均具有间隔空间，两个所述反射栅用于将泄露到叉指电极的两端的声波信号反射回所述叉指电极。
  10. 根据权利要求9所述的声表面波谐振器，其特征在于，所述叉指电极的数量为多个，多个所述叉指电极沿垂直于所述第一指条的方向依次串联设置，两个所述反射栅沿垂直于所述第一指条的方向设置于多个依次串联的叉指电极的两端，且两个所述反射栅与多个依次串联的叉指电极之间均具有间隔空间。
  11. 一种声表面波滤波器，其特征在于，包括依次层叠设置的支撑衬底、 温度补偿层和压电衬底，以及设置于所述压电衬底上的声表面波谐振器，所述声表面波谐振器为权利要求1-10任一项所述的声表面波谐振器。
PCT/CN2023/070901 2022-04-08 2023-01-06 声表面波谐振器及声表面波滤波器 WO2023193499A1 (zh)

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