CN219718197U - Surface acoustic wave resonator - Google Patents
Surface acoustic wave resonator Download PDFInfo
- Publication number
- CN219718197U CN219718197U CN202321024255.2U CN202321024255U CN219718197U CN 219718197 U CN219718197 U CN 219718197U CN 202321024255 U CN202321024255 U CN 202321024255U CN 219718197 U CN219718197 U CN 219718197U
- Authority
- CN
- China
- Prior art keywords
- interdigital
- acoustic wave
- surface acoustic
- electrode
- inclined surface
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000010897 surface acoustic wave method Methods 0.000 title claims abstract description 143
- 239000000758 substrate Substances 0.000 claims abstract description 17
- 230000007423 decrease Effects 0.000 claims abstract description 10
- 239000000463 material Substances 0.000 claims description 17
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 8
- 238000000034 method Methods 0.000 claims description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 5
- 229910013641 LiNbO 3 Inorganic materials 0.000 claims description 5
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 5
- 229910052782 aluminium Inorganic materials 0.000 claims description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 5
- 229910052802 copper Inorganic materials 0.000 claims description 5
- 239000010949 copper Substances 0.000 claims description 5
- 229910052594 sapphire Inorganic materials 0.000 claims description 5
- 239000010980 sapphire Substances 0.000 claims description 5
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 4
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 4
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 4
- 229910052804 chromium Inorganic materials 0.000 claims description 4
- 239000011651 chromium Substances 0.000 claims description 4
- 229910052759 nickel Inorganic materials 0.000 claims description 4
- 229910052709 silver Inorganic materials 0.000 claims description 4
- 239000004332 silver Substances 0.000 claims description 4
- 229910052719 titanium Inorganic materials 0.000 claims description 4
- 239000010936 titanium Substances 0.000 claims description 4
- 230000003247 decreasing effect Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- JRBRVDCKNXZZGH-UHFFFAOYSA-N alumane;copper Chemical compound [AlH3].[Cu] JRBRVDCKNXZZGH-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000007888 film coating Substances 0.000 description 1
- 238000009501 film coating Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 238000001259 photo etching Methods 0.000 description 1
Landscapes
- Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
Abstract
The utility model discloses a surface acoustic wave resonator, which comprises a piezoelectric substrate and an interdigital transducer arranged on the piezoelectric substrate, wherein the interdigital transducer comprises a first interdigital bus bar and a second interdigital bus bar; the first interdigital bus bar extends out of the first interdigital electrode and the first dummy electrode, and the second interdigital bus bar extends out of the second interdigital electrode and the second dummy electrode; wherein the width of the interdigital electrode region gradually decreases in a direction away from the symmetry axis of the interdigital transducer; the end face of the first interdigital electrode, which is opposite to the corresponding second dummy electrode, is a first inclined face, the end face of the second interdigital electrode, which is opposite to the corresponding first dummy electrode, is a second inclined face, and the inclination angles of the first inclined face and/or the second inclined face are consistent along the surface acoustic wave propagation direction in the same direction and are positioned on the same inclined plane. The surface acoustic wave resonator provided by the embodiment of the utility model can effectively inhibit the transverse resonant mode.
Description
Technical Field
The utility model relates to the technical field of resonators, in particular to a surface acoustic wave resonator.
Background
The surface acoustic wave resonator is used as the core of the surface acoustic wave filter, and parameters such as frequency, electromechanical coupling coefficient, Q value (quality factor) and the like directly affect the performance of the surface acoustic wave filter. Along with the development of the surface acoustic wave resonator technology, the surface acoustic wave resonator in the related technology has high frequency, high electromechanical coupling coefficient and high Q value, but a transverse resonant mode exists in the surface acoustic wave resonator, so that a burr type ripple is generated on the admittance characteristic curve of the surface acoustic wave resonator, and passband ripple is influenced when the surface acoustic wave resonator is used on a surface acoustic wave filter, which is a harmful clutter. Therefore, in order to improve the performance of the surface acoustic wave filter, it is necessary to suppress the transverse resonant mode of the surface acoustic wave resonator.
Disclosure of Invention
The present utility model aims to solve at least one of the technical problems in the related art to some extent.
To this end, an embodiment of the present utility model proposes a surface acoustic wave resonator to suppress a transverse resonant mode of the surface acoustic wave resonator.
The surface acoustic wave resonator comprises a piezoelectric substrate and an interdigital transducer arranged on the piezoelectric substrate, wherein the interdigital transducer comprises a first interdigital bus bar and a second interdigital bus bar; the first interdigital bus bar extends to form a first interdigital electrode and a first dummy electrode, and the second interdigital bus bar extends to form a second interdigital electrode corresponding to the first dummy electrode and a second dummy electrode corresponding to the first interdigital electrode; wherein, the area where the first interdigital electrode and the second interdigital electrode are intersected forms an interdigital electrode area, the interdigital transducer is symmetrically arranged along the surface acoustic wave propagation direction, and the width of the interdigital electrode area gradually decreases along the direction away from the symmetrical axis of the interdigital transducer; the end face of the first interdigital electrode, which is opposite to the corresponding second dummy electrode, is a first inclined face, and the first inclined face is obliquely arranged along the propagation direction of the surface acoustic wave; the end face of the second interdigital electrode, which is opposite to the corresponding first dummy electrode, is a second inclined face, and the second inclined face is obliquely arranged along the propagation direction of the surface acoustic wave; the inclination angles of the first inclined surfaces are consistent along the propagation direction of the surface acoustic wave and are positioned on the same inclined plane in the same direction, and/or the inclination angles of the second inclined surfaces are consistent along the same direction and are positioned on the same inclined plane.
In some embodiments, an end face of the first dummy electrode opposite to the corresponding second interdigital electrode is a third inclined face, the third inclined face being obliquely arranged along the surface acoustic wave propagation direction; the end face of the second dummy electrode, which is opposite to the corresponding first interdigital electrode, is a fourth inclined face, and the fourth inclined face is obliquely arranged along the propagation direction of the surface acoustic wave; the third inclined surface and the first inclined surface are opposite in inclination direction along the propagation direction of the surface acoustic wave, the inclination angles of the third inclined surfaces are consistent in the same direction and are positioned on the same inclined plane, and/or the fourth inclined surface and the second inclined surface are opposite in inclination direction in the same direction, and the inclination angles of the fourth inclined surfaces are consistent in the same inclined plane in the same direction.
In some embodiments, the first inclined surface and/or the second inclined surface has an inclination angle of 2 ° to 15 °.
In some embodiments, an end face of the first interdigital bus bar remote from the first interdigital electrode is a fifth inclined face, the fifth inclined face being obliquely arranged along the surface acoustic wave propagation direction; and/or, an end face of the second interdigital bus bar far away from the second interdigital electrode is a sixth inclined face, and the sixth inclined face is obliquely arranged along the surface acoustic wave propagation direction.
In some embodiments, the interdigital transducer further comprises a reflective grating disposed on both sides of the interdigital electrode region in the direction of propagation of the surface acoustic wave, the reflective grating comprising a plurality of reflective finger electrodes; the area of the reflecting grating provided with the reflecting finger electrode is a reflecting electrode area, the reflecting electrode area is arranged corresponding to the interdigital electrode area, and the width of the reflecting electrode area gradually decreases along the direction far away from the symmetrical axis.
In some embodiments, one of the end surfaces of the reflecting grating, which is far away from the reflecting finger electrode, is a seventh inclined surface, and the seventh inclined surface is obliquely arranged along the propagation direction of the surface acoustic wave; the other end face of the reflecting grating, which is far away from the reflecting finger electrode, is an eighth inclined face, and the eighth inclined face is obliquely arranged along the propagation direction of the surface acoustic wave.
In some embodiments, the material of the interdigital transducer is one or a combination of more of aluminum, copper, titanium, chromium, silver, and nickel.
In some embodiments, the piezoelectric substrate includes a support layer, a dielectric layer, and a piezoelectric layer disposed in sequence, the interdigital transducer being disposed on the piezoelectric layer.
In some embodiments, the material of the support layer is Si, siC, or sapphire; and/or the material of the dielectric layer is SiO 2 The method comprises the steps of carrying out a first treatment on the surface of the And/or the material of the piezoelectric layer is LiTaO 3 Or LiNbO 3 。
According to the surface acoustic wave resonator, the interdigital transducers are symmetrically arranged along the surface acoustic wave propagation direction, so that the energy distribution on two sides of the symmetrical axis of the interdigital transducers is uniform, and stable signal propagation is realized; by setting the width of the interdigital electrode region formed by the first interdigital electrode and the second interdigital electrode to gradually decrease in a direction away from the symmetry axis of the interdigital transducer, the transverse resonance mode of the surface acoustic wave resonator, that is, the transverse resonance mode of the surface acoustic wave resonator can be reduced; the inclination angles of the first inclined surfaces in the same direction are consistent and positioned on the same inclined plane in the surface acoustic wave propagation direction, and/or the inclination angles of the second inclined surfaces in the same direction are consistent and positioned on the same inclined plane, so that the end surfaces of the first interdigital electrodes can keep good continuity, and the Q value of the surface acoustic wave resonator is improved. Thus, the performance of the surface acoustic wave resonator can be effectively improved, and the performance of the surface acoustic wave filter with the surface acoustic wave resonator can be effectively improved.
Drawings
Fig. 1 is a schematic structural view of a surface acoustic wave resonator according to an embodiment of the present utility model.
Fig. 2 is a view in the A-A direction of fig. 1.
Fig. 3 is a schematic structural view of a surface acoustic wave resonator according to another embodiment of the present utility model.
Fig. 4 is a schematic structural view of a surface acoustic wave resonator according to still another embodiment of the present utility model.
Fig. 5 is a graph of admittance characteristics (tilt angle of 4 °) of a surface acoustic wave resonator according to an embodiment of the present utility model.
Fig. 6 is a graph of admittance characteristics (inclination angle of 6 °) of a surface acoustic wave resonator according to an embodiment of the present utility model.
Fig. 7 is a graph of admittance characteristics (inclination angle of 8 °) of a surface acoustic wave resonator according to an embodiment of the present utility model.
Fig. 8 is a graph of admittance characteristics (inclination angle of 10 °) of a surface acoustic wave resonator according to an embodiment of the present utility model.
Fig. 9 is an admittance characteristic diagram (inclination angle of 0 °) of a surface acoustic wave resonator in the related art.
Fig. 10 is a graph of Q-value characteristics (inclination angle of 4 °) of a surface acoustic wave resonator according to an embodiment of the present utility model.
Fig. 11 is a graph of Q-value characteristics (inclination angle is 6 °) of a surface acoustic wave resonator according to an embodiment of the present utility model.
Fig. 12 is a graph of Q-value characteristics (inclination angle of 8 °) of a surface acoustic wave resonator according to an embodiment of the present utility model.
Fig. 13 is a graph of Q-value characteristics (inclination angle of 10 °) of a surface acoustic wave resonator according to an embodiment of the present utility model.
Reference numerals:
100. a surface acoustic wave resonator;
1. a piezoelectric substrate; 11. a support layer; 12. a dielectric layer; 13. a piezoelectric layer;
2. an interdigital transducer; 21. a first interdigital busbar; 211. a fifth inclined surface; 22. a second interdigital bus bar; 221. a sixth inclined surface; 23. a first interdigital electrode; 231. a first inclined surface; 24. a first dummy electrode; 241. a third inclined surface; 25. a second interdigital electrode; 251. a second inclined surface; 26. a second dummy electrode; 261. a fourth inclined surface; 27. a reflective grating; 271. a reflective finger electrode; 272. a seventh inclined surface; 273. an eighth inclined surface; 201. an interdigital electrode region; 202. and a reflective electrode region.
Detailed Description
Reference will now be made in detail to embodiments of the present utility model, examples of which are illustrated in the accompanying drawings. The embodiments described below by referring to the drawings are illustrative and intended to explain the present utility model and should not be construed as limiting the utility model.
As shown in fig. 1 to 4, a surface acoustic wave resonator 100 of an embodiment of the present utility model includes a piezoelectric substrate 1 and an interdigital transducer 2, the interdigital transducer 2 being disposed on the piezoelectric substrate 1. The interdigital transducer 2 includes a first interdigital bus bar 21 and a second interdigital bus bar 22. The first interdigital bus bar 21 extends out of the first interdigital electrode 23 and the first dummy electrode 24, and the second interdigital bus bar 22 extends out of the second interdigital electrode 25 corresponding to the first dummy electrode 24 and the second dummy electrode 26 corresponding to the first interdigital electrode 23. The region where the first interdigital electrode 23 and the second interdigital electrode 25 intersect forms an interdigital electrode region 201, the interdigital transducer 2 being symmetrically arranged along its surface acoustic wave propagation direction, the width of the interdigital electrode region 201 gradually decreasing in a direction away from the symmetry axis of the interdigital transducer 2. Wherein the width direction of the interdigital electrode region 201 is perpendicular to the surface acoustic wave propagation direction of the interdigital transducer 2 and the thickness direction of the piezoelectric substrate 1.
The end face of the first interdigital electrode 23 opposite to the corresponding second dummy electrode 26 is a first inclined face 231, and the first inclined face 231 is arranged obliquely in the surface acoustic wave propagation direction. The end face of the second interdigital electrode 25 opposite to the corresponding first dummy electrode 24 is a second inclined face 251, and the second inclined face 251 is arranged obliquely in the acoustic surface acoustic wave propagation direction.
In the surface acoustic wave propagation direction, the inclination angles of the first inclined surfaces 231 are identical and lie on the same inclined plane, and/or the inclination angles of the second inclined surfaces 251 are identical and lie on the same inclined plane. In other words, in the surface acoustic wave propagation direction, the inclination angles of the first inclined surfaces 231 are identical and lie on the same inclined plane, and in the same direction, the inclination angles of the second inclined surfaces 251 may or may not be identical; alternatively, the inclination angles of the second inclined surfaces 251 may be identical and lie on the same inclined plane in the same direction as the propagation direction of the surface acoustic wave, and the inclination angles of the first inclined surfaces 231 may be identical or not identical in the same direction.
As known to those skilled in the art, the surface acoustic wave propagation direction of the interdigital transducer 2 is such that it propagates from the center of the interdigital transducer 2 to both sides, and in particular, it is understood that it propagates from the symmetry axis to both sides away from the symmetry axis. For example, as shown in fig. 1, the symmetry axis is a straight line a, each of the first inclined surfaces 231 located on the same side of the straight line a in the surface acoustic wave propagation direction is a first inclined surface 231 in the same direction, and each of the second inclined surfaces 251 located on the same side of the straight line a in the surface acoustic wave propagation direction is a second inclined surface 251 in the same direction.
According to the surface acoustic wave resonator 100 provided by the embodiment of the utility model, the interdigital transducer 2 is symmetrically arranged along the surface acoustic wave propagation direction, so that the energy distribution at two sides of the symmetrical axis of the interdigital transducer 2 is more uniform, and the stable and stable propagation of signals is realized; by setting the width of the interdigital electrode region 201 formed by the first interdigital electrode 23 and the second interdigital electrode 25 to gradually decrease in a direction away from the symmetry axis of the interdigital transducer 2, the transverse resonance mode of the surface acoustic wave resonator 100, i.e., the transverse resonance mode of the surface acoustic wave resonator 100 is suppressed (as shown in fig. 5 to 9); by setting the inclination angles of the first inclined surfaces 231 in the same direction to be uniform and on the same inclined plane and/or setting the inclination angles of the second inclined surfaces 251 in the same direction to be uniform and on the same inclined plane in the surface acoustic wave propagation direction, the end surfaces of the first interdigital electrodes 23 can be kept well continuous, which is advantageous for improving the Q value of the surface acoustic wave resonator 100.
Thus, the performance of the surface acoustic wave resonator 100 can be effectively improved, and the performance of the surface acoustic wave filter having the surface acoustic wave resonator 100 can be effectively improved.
If the total number of the first and second interdigital electrodes 23 and 25 is an even number, the symmetry axis is a middle line between the first and second interdigital electrodes 23 and 25 located at the middle, and each of the first and second inclined surfaces 231 and 251 is a complete inclined surface.
If the total number of the first and second interdigital electrodes 23 and 25 is an odd number, the axis of symmetry is the central axis of the one interdigital electrode located in the middle. At this time, both sides of the end face of one interdigital electrode located in the middle are inclined to both sides, respectively. For example, when the total number of the first and second interdigital electrodes 23 and 25 is an odd number and the number of the first interdigital electrodes 23 is greater than the number of the second interdigital electrodes 25, the central axis of one first interdigital electrode 23 located in the middle is the axis of symmetry, and both sides of the end face of the first interdigital electrode 23 located in the middle, which is away from the first interdigital bus bar 21, are inclined to both sides, respectively.
In order to make the technical solution of the present utility model easier to understand, the technical solution of the present utility model will be further described by taking the case that the propagation direction of the surface acoustic wave of the interdigital transducer 2 coincides with the left-right direction and the width direction of the interdigital electrode region 201 coincides with the front-rear direction as an example. The left-right direction is shown in fig. 1 to 4, and the front-rear direction is shown in fig. 1, 3 and 4.
For example, as shown in fig. 1, 3, and 4, the first and second interdigital bus bars 21 and 22 are disposed opposite in the front-rear direction, and the first interdigital bus bar 21 is disposed on the front side of the second interdigital bus bar 22. The first interdigital bus bar 21 extends backward to form a first interdigital electrode 23 and a first dummy electrode 24, the second interdigital bus bar 22 extends forward to form a second interdigital electrode 25 and a second dummy electrode 26, the first interdigital electrode 23 is disposed on the front side of the corresponding second dummy electrode 26, the first dummy electrode 24 is disposed on the front side of the corresponding second interdigital electrode 25, and the plurality of first interdigital electrodes 23 and the plurality of second interdigital electrodes 25 are alternately arranged at intervals in the left-right direction. The width of the inter-digital electrode region 201 is the dimension of the inter-digital electrode region 201 in the front-rear direction. The straight line a extends in the front-rear direction, and the width of the interdigital electrode region 201 provided on the left side of the straight line a gradually decreases in the right-to-left direction, and the width of the interdigital electrode region 201 provided on the right side of the straight line a gradually decreases in the left-to-right direction. The rear end surface of the first interdigital electrode 23 is a first inclined surface 231, the first inclined surface 231 located on the left side of the straight line a gradually slopes rearward in the left-to-right direction, and the first inclined surface 231 located on the right side of the straight line a gradually slopes forward in the left-to-right direction. The front end surface of the second interdigital electrode 25 is a second inclined surface 251, the second inclined surface 251 located on the left side of the straight line a gradually slopes forward in the left-to-right direction, and the second inclined surface 251 located on the right side of the straight line a gradually slopes backward in the left-to-right direction.
A first gap is provided between the first interdigital electrode 23 and the corresponding second dummy electrode 26, and a second gap is provided between the second interdigital electrode 25 and the corresponding first dummy electrode 24, and the size of the first gap is equal to that of the second gap.
Alternatively, the lengths of the plurality of first dummy electrodes 24 are equal, and the lengths of the plurality of second dummy electrodes 26 are equal. The length of the first dummy electrode 24 is the dimension of the first dummy electrode 24 in the width direction of the interdigital electrode region 201, and the length of the second dummy electrode 26 is the dimension of the second dummy electrode 26 in the width direction of the interdigital electrode region 201.
For example, as shown in fig. 1, 3, and 4, the length of the first dummy electrode 24 is the size of the first dummy electrode 24 in the front-rear direction, and the length of the second dummy electrode 26 is the size of the second dummy electrode 26 in the front-rear direction. The plurality of first dummy electrodes 24 are equal in size in the front-rear direction, and the plurality of second dummy electrodes 26 are equal in size in the front-rear direction.
Alternatively, the end face of the first dummy electrode 24 opposite to the corresponding second interdigital electrode 25 is a third inclined face 241, the third inclined face 241 is arranged obliquely in the surface acoustic wave propagation direction, the end face of the second dummy electrode 26 opposite to the corresponding first interdigital electrode 23 is a fourth inclined face 261, and the fourth inclined face 261 is arranged obliquely in the surface acoustic wave propagation direction.
The third inclined surfaces 241 are opposite to the inclined direction of the first inclined surfaces 231 in the same direction along the propagation direction of the surface acoustic wave, and the inclined angles of the third inclined surfaces 241 are identical in the same direction and are located on the same inclined plane, and/or the fourth inclined surfaces 261 are opposite to the inclined direction of the second inclined surfaces 251 in the same direction, and the inclined angles of the fourth inclined surfaces 261 are identical in the same direction and are located on the same inclined plane. In other words, in the same direction along which the surface acoustic wave propagates, the inclination directions of the third inclined surfaces 241 and the first inclined surfaces 231 are opposite, and in the same direction, the inclination angles of the third inclined surfaces 241 are identical, and the inclination directions of the fourth inclined surfaces 261 and the second inclined surfaces 251 in the same direction may be the same or opposite; alternatively, the inclination angles of the fourth inclined surfaces 261 are identical in the same direction in which the fourth inclined surfaces 261 and the second inclined surfaces 251 are inclined in the same direction, and the inclination directions of the third inclined surfaces 241 and the first inclined surfaces 231 in the same direction may be the same or opposite in the same inclined plane.
For example, as shown in fig. 1, 3 and 4, the rear end surface of the first dummy electrode 24 is a third inclined surface 241, and the third inclined surface 241 and the first inclined surface 231 on the same side of the straight line a in the left-right direction have opposite inclination directions, and the inclination angles of the third inclined surfaces 241 on the same side of the straight line a in the left-right direction are identical and are on the same inclined plane. The front end surface of the second dummy electrode 26 is a fourth inclined surface 261, and the fourth inclined surface 261 and the second inclined surface 251 which are positioned on the same side of the straight line a in the left-right direction have opposite inclination directions, and the inclination angles of the fourth inclined surfaces 261 which are positioned on the same side of the straight line a in the left-right direction are identical and are positioned on the same inclined plane.
Along the propagation direction of the surface acoustic wave, the inclination directions of the third inclined surfaces 241 and the first inclined surfaces 231 are opposite in the same direction, and the inclination angles of the third inclined surfaces 241 are identical in the same direction and are located on the same inclined plane, so that the distance from the acoustic wave excited by the end part of each second interdigital electrode 25 to the first interdigital bus bar 21 is kept identical, and clutter generated due to inconsistent propagation distances of boundary reflection acoustic waves is avoided. In the same direction, the inclination directions of the fourth inclined surfaces 261 and the second inclined surfaces 251 are opposite, and in the same direction, the inclination angles of the fourth inclined surfaces 261 are identical and are located on the same inclined plane, so that the distance from the sound wave excited by the end part of each first interdigital electrode 23 to the second interdigital bus bar 22 is kept identical, and clutter generated due to inconsistent propagation distances of boundary reflection sound waves is avoided.
This contributes to further suppressing the transverse resonant mode of the surface acoustic wave resonator 100, thereby further improving the performance of the surface acoustic wave filter having the surface acoustic wave resonator 100.
Alternatively, the first inclined surface 231 may have an inclination angle of 2 ° to 15 °. In other words, the inclination angle of the first inclined surface 231 in the propagation direction of the surface acoustic wave is 2 ° to 15 °.
For example, as shown in fig. 1, the inclination angle of the first inclined surface 231 is α, or, the included angle α between the first inclined surface 231 and the propagation direction of the surface acoustic wave is 2 ° to 15 °.
If the inclination angle of the first inclined surface 231 is too large, the Q value of the surface acoustic wave resonator 100 cannot be improved correspondingly; if the inclination angle of the first inclined surface 231 is too small, it is difficult to achieve the same by the existing process, and the implementation cost is too high. By setting the inclination angle of the first inclined surface 231 to 2 ° to 15 °, the Q value of the surface acoustic wave resonator 100 can be effectively increased while reducing the manufacturing cost of the surface acoustic wave resonator 100.
Preferably, the first inclined surface 231 has an inclination angle of 4 ° to 10 °.
Alternatively, the second inclined surface 251 may have an inclination angle of 2 ° to 15 °. In other words, the inclination angle of the second inclined surface 251 in the surface acoustic wave propagation direction is 2 ° to 15 °.
For example, as shown in fig. 1, the inclination angle of the second inclined surface 251 is β, or the included angle β between the second inclined surface 251 and the propagation direction of the surface acoustic wave is 2 ° to 15 °.
If the inclination angle of the second inclined surface 251 is too large, the Q value of the surface acoustic wave resonator 100 cannot be improved correspondingly; if the inclination angle of the second inclined surface 251 is too small, it is difficult to achieve the same by the conventional process, and the realization cost is too high. By setting the inclination angle of the second inclined surface 251 to 2 ° to 15 °, the Q value of the surface acoustic wave resonator 100 can be effectively increased while reducing the manufacturing cost of the surface acoustic wave resonator 100.
Preferably, the inclination angle of the second inclined surface 251 is 4 ° to 10 °.
Alternatively, the end surface of the first interdigital bus bar 21 remote from the first interdigital electrode 23 is a fifth inclined surface 211, and the fifth inclined surface 211 is arranged obliquely in the surface acoustic wave propagation direction.
For example, as shown in fig. 4, the front end surface of the first interdigital bus bar 21 is a fifth inclined surface 211, and the first interdigital bus bar 21 has two fifth inclined surfaces 211, the two fifth inclined surfaces 211 being located on both sides of the symmetry axis. The fifth inclined surface 211 positioned at the left side of the straight line a gradually slopes forward in the left-to-right direction, and the fifth inclined surface 211 positioned at the right side of the straight line a gradually slopes backward in the left-to-right direction.
Thereby, the size of the first interdigital bus bar 21 in the width direction of the interdigital electrode region 201 is favorably reduced, thereby favorably reducing the amount of material of the first interdigital bus bar 21 and reducing the cost of the surface acoustic wave resonator 100.
Alternatively, the fifth inclined surface 211 is disposed parallel to the second inclined surface 251 adjacent thereto.
For example, as shown in fig. 4, the fifth inclined surface 211 positioned on the left side of the straight line a is disposed in parallel with the second inclined surface 251 positioned on the left side of the straight line a, and the fifth inclined surface 211 positioned on the right side of the straight line a is disposed in parallel with the second inclined surface 251 positioned on the right side of the straight line a.
Alternatively, the end face of the second interdigital bus bar 22 remote from the second interdigital electrode 25 is a sixth inclined face 221, and the sixth inclined face 221 is arranged obliquely in the surface acoustic wave propagation direction.
For example, as shown in fig. 4, the front end surface of the second interdigital bus bar 22 is a sixth inclined surface 221, and the second interdigital bus bar 22 has two sixth inclined surfaces 221, the two sixth inclined surfaces 221 being located on both sides of the symmetry axis. The sixth inclined surface 221 located at the left side of the straight line a is gradually inclined rearward in the left-to-right direction, and the sixth inclined surface 221 located at the right side of the straight line a is gradually inclined forward in the left-to-right direction.
Thereby, it is advantageous to reduce the size of the second interdigital bus bar 22 in the width direction of the interdigital electrode region 201, thereby advantageously reducing the amount of material of the second interdigital bus bar 22 and reducing the cost of the surface acoustic wave resonator 100.
Alternatively, the sixth inclined surface 221 is disposed parallel to the second inclined surface 251 adjacent thereto.
For example, as shown in fig. 4, the sixth inclined surface 221 located on the left side of the straight line a is provided in parallel with the second inclined surface 251 located on the left side of the straight line a, and the sixth inclined surface 221 located on the right side of the straight line a is provided in parallel with the second inclined surface 251 located on the right side of the straight line a.
As shown in fig. 1 and 3, in other embodiments, the end face of the first interdigital bus bar 21 remote from the first interdigital electrode 23 and the end face of the second interdigital bus bar 22 remote from the second interdigital electrode 25 are parallel to the surface acoustic wave propagation direction.
Thus, the entire area surrounded by the first interdigital bus bar 21 and the second interdigital bus bar 22 is rectangular, and compared with the case where the entire area surrounded by the first interdigital bus bar 21 and the second interdigital bus bar 22 is inclined along the propagation direction of the surface acoustic wave, the layout compactness of the surface acoustic wave resonator 100 can be effectively improved, and the layout size can be reduced.
In some embodiments, as shown in fig. 1, 3 and 4, the surface acoustic wave resonator 100 further includes reflective gratings 27 disposed on both sides of the interdigital electrode region 201 in the propagation direction of the surface acoustic wave, and the reflective gratings 27 include a plurality of reflective finger electrodes 271, wherein the region of the reflective grating 27 where the reflective finger electrodes 271 are disposed is a reflective electrode region 202, the reflective electrode region 202 is disposed corresponding to the interdigital electrode region 201, and the width of the reflective electrode region 202 gradually decreases in a direction away from the symmetry axis. The width direction of the reflection electrode region 202 is perpendicular to the surface acoustic wave propagation direction of the interdigital transducer 2 and the thickness direction of the piezoelectric substrate 1.
For example, as shown in fig. 1 and 4, both the left and right sides of the interdigital electrode region 201 are provided with reflective gratings 27. The plurality of reflective finger electrodes 271 are arranged at intervals in the left-right direction. The reflection electrode region 202 and the interdigital electrode region 201 are disposed opposite to each other in the left-right direction. A reflective grating 27 provided on the left side of the interdigital transducer 2, the width of the reflective electrode region 202 gradually decreasing in the right-to-left direction; the width of the reflective electrode region 202 of the reflective grating 27 disposed on the right side of the interdigital transducer 2 gradually decreases in the left-to-right direction.
The Q value of the surface acoustic wave resonator in the prior art is usually 4000, and the quality factor of the surface acoustic wave resonator is low.
As shown in fig. 10 to 13, by arranging the reflective electrode regions 202 corresponding to the interdigital electrode regions 201, and gradually decreasing the width of the reflective electrode regions 202 along the direction away from the symmetry axis, the width of the interdigital electrode regions 201 and the width of the reflective electrode regions 202 maintain good continuity, so that the Q value of the surface acoustic wave resonator 100 can be increased to 7000 or more, which is beneficial to increasing the Q value of the surface acoustic wave resonator 100.
Alternatively, one of the end surfaces of the reflection grating 27 disposed away from the reflection finger electrode 271 is a seventh inclined surface 272, and the seventh inclined surface 272 is arranged obliquely in the surface acoustic wave propagation direction.
For example, as shown in fig. 1 and 4, the front end surface of each reflecting grating 27 is a seventh inclined surface 272, the seventh inclined surface 272 located on the left side of the straight line a gradually slopes forward in the left-to-right direction, and the fifth inclined surface 211 located on the right side of the straight line a gradually slopes backward in the left-to-right direction.
Thereby, it is advantageous to reduce the size of the reflection grating 27 in the width direction of the interdigital electrode region 201, thereby advantageously reducing the material amount of the reflection grating 27 and reducing the cost of the surface acoustic wave resonator 100.
Alternatively, the seventh inclined surface 272 is disposed closer to the second inclined surface 251 than the first inclined surface 231, and the seventh inclined surface 272 is disposed parallel to the second inclined surface 251 adjacent thereto.
For example, as shown in fig. 1 and 4, the seventh inclined surface 272 located on the left side of the straight line a is disposed in parallel with the second inclined surface 251 located on the left side of the straight line a, and the seventh inclined surface 272 located on the right side of the straight line a is disposed in parallel with the second inclined surface 251 located on the right side of the straight line a.
Alternatively, the other end surface of the reflection grating 27, which is disposed away from the reflection finger electrode 271, is an eighth inclined surface 273, and the eighth inclined surface 273 is arranged obliquely in the surface acoustic wave propagation direction.
For example, as shown in fig. 1 and 4, the front end surface of each reflecting grating 27 is an eighth inclined surface 273, the eighth inclined surface 273 located on the left side of the straight line a is gradually inclined rearward in the left-to-right direction, and the fifth inclined surface 211 located on the right side of the straight line a is gradually inclined forward in the left-to-right direction.
Thereby, it is advantageous to reduce the size of the reflection grating 27 in the width direction of the interdigital electrode region 201, thereby advantageously reducing the material amount of the reflection grating 27 and reducing the cost of the surface acoustic wave resonator 100.
Alternatively, the eighth inclined surface 273 is disposed closer to the first inclined surface 231 than the second inclined surface 251, and the eighth inclined surface 273 is disposed parallel to the first inclined surface 231 adjacent thereto.
For example, as shown in fig. 1 and 4, the eighth inclined surface 273 on the left side of the straight line a is disposed in parallel with the first inclined surface 231 on the left side of the straight line a, and the eighth inclined surface 273 on the right side of the straight line a is disposed in parallel with the first inclined surface 231 on the right side of the straight line a.
Alternatively, as shown in fig. 1, the piezoelectric substrate 1 includes a support layer 11, a dielectric layer 12, and a piezoelectric layer 13 disposed in this order, and the interdigital transducer 2 is disposed on the piezoelectric layer 13.
By providing the piezoelectric substrate 1 including the support layer 11, the dielectric layer 12, and the piezoelectric layer 13, which are sequentially provided, and providing the interdigital transducer 2 on the piezoelectric layer 13, it is advantageous to further improve the performance of the surface acoustic wave resonator 100.
Alternatively, the material of the support layer 11 is Si, siC, or sapphire.
The supporting strength of Si, siC or sapphire is good, and the supporting layer 11 is made of Si, siC or sapphire, so that the supporting reliability of the supporting layer 11 is improved, and the reliability of the surface acoustic wave resonance 100 is improved.
Optionally, the material of the dielectric layer 12 is SiO 2 。
SiO 2 Can function to enhance bonding force and temperature compensation, the material of the dielectric layer 12SiO is adopted 2 It is advantageous to further improve the performance of the surface acoustic wave resonator 100.
Optionally, the material of the piezoelectric layer 13 is LiTaO 3 Or LiNbO 3 。
LiTaO 3 Or LiNbO 3 The piezoelectric layer 13 is made of LiTaO with good piezoelectric performance 3 Or LiNbO 3 It is advantageous to further improve the performance of the surface acoustic wave resonator 100.
Alternatively, the material of the interdigital transducer 2 is one or a combination of more of aluminum, copper, titanium, chromium, silver, and nickel.
For example, the material of the interdigital transducer 2 is aluminum, copper, or copper-aluminum alloy, or the material of the interdigital transducer 2 is a metal film formed of at least one of aluminum and copper and at least one of titanium, chromium, silver, and nickel.
The surface acoustic wave resonator 100 according to the embodiment of the present utility model may be manufactured by the following method:
deposition of SiO on Si substrates 2 (or oxidizing the Si substrate surface to SiO) 2 ) In SiO 2 Surface-bonded LiTaO 3 And thinning the LT wafer by the Smart-Cut technology and the like to form the POI wafer. And manufacturing the interdigital transducer 2 on the surface of the POI wafer through mask photoetching, film coating, litoff and other processes.
The surface acoustic wave resonator 100 of the embodiment of the utility model can effectively eliminate clutter such as a transverse mode of the interdigital transducer 2, inhibit a transverse resonant mode of the surface acoustic wave resonator 100 and improve the performance of a surface acoustic wave filter with the surface acoustic wave resonator 100.
The surface acoustic wave filter according to the embodiment of the present utility model includes the surface acoustic wave resonator 100 according to any of the embodiments described above.
Therefore, the surface acoustic wave filter provided by the embodiment of the utility model has the advantages of good performance and the like.
While embodiments of the present utility model have been shown and described above, it should be understood that the above embodiments are illustrative and not to be construed as limiting the utility model, and that variations, modifications, alternatives, and variations of the above embodiments may be made by those skilled in the art without departing from the scope of the utility model.
Claims (9)
1. A surface acoustic wave resonator (100), comprising:
a piezoelectric substrate (1);
an interdigital transducer (2) arranged on the piezoelectric substrate (1), wherein the interdigital transducer (2) comprises a first interdigital bus bar (21), a second interdigital bus bar (22) and a reflecting grating (27);
the first interdigital bus bar (21) extends to form a first interdigital electrode (23) and a first dummy electrode (24), and the second interdigital bus bar (22) extends to form a second interdigital electrode (25) corresponding to the first dummy electrode (24) and a second dummy electrode (26) corresponding to the first interdigital electrode (23);
wherein the region where the first interdigital electrode (23) and the second interdigital electrode (25) intersect forms an interdigital electrode region (201), the interdigital transducer (2) is symmetrically arranged along the surface acoustic wave propagation direction thereof, and the width of the interdigital electrode region (201) gradually decreases along the direction away from the symmetry axis of the interdigital transducer (2);
an end surface of the first interdigital electrode (23) opposite to the corresponding second dummy electrode (26) is a first inclined surface (231), and the first inclined surface (231) is obliquely arranged along the propagation direction of the surface acoustic wave;
an end face of the second interdigital electrode (25) opposite to the corresponding first dummy electrode (24) is a second inclined face (251), and the second inclined face (251) is obliquely arranged along the surface acoustic wave propagation direction.
2. The surface acoustic wave resonator (100) according to claim 1, characterized in that,
the first inclined surfaces (231) are inclined at the same angle and on the same inclined plane in the same direction as the propagation direction of the surface acoustic wave, and/or
In the same direction, the inclination angles of the second inclined surfaces (251) are identical and are positioned on the same inclined plane.
3. The surface acoustic wave resonator (100) according to claim 1, characterized in that an end surface of the first dummy electrode (24) opposite to the corresponding second interdigital electrode (25) is a third inclined surface (241), the third inclined surface (241) being arranged obliquely along the surface acoustic wave propagation direction;
an end surface of the second dummy electrode (26) opposite to the corresponding first interdigital electrode (23) is a fourth inclined surface (261), and the fourth inclined surface (261) is obliquely arranged along the propagation direction of the surface acoustic wave;
the third inclined surface (241) is opposite to the first inclined surface (231) in the same direction along the propagation direction of the surface acoustic wave, and the inclination angles of the third inclined surfaces (241) are consistent and are positioned on the same inclined plane, and/or
The fourth inclined surfaces (261) are opposite to the second inclined surfaces (251) in the same direction, and the inclination angles of the fourth inclined surfaces (261) are identical in the same direction and are located on the same inclined plane.
4. The surface acoustic wave resonator (100) according to claim 1, characterized in that the inclination angle of the first inclined surface (231) and/or the second inclined surface (251) is 2 ° to 15 °.
5. The surface acoustic wave resonator (100) according to claim 1, characterized in that an end surface of the first interdigital bus bar (21) remote from the first interdigital electrode (23) is a fifth inclined surface (211), the fifth inclined surface (211) being arranged obliquely along the surface acoustic wave propagation direction; and/or
An end surface of the second interdigital bus bar (22) away from the second interdigital electrode (25) is a sixth inclined surface (221), and the sixth inclined surface (221) is obliquely arranged along the surface acoustic wave propagation direction.
6. The surface acoustic wave resonator (100) according to claim 1, characterized in that one of end surfaces of the reflection grating (27) which is disposed away from the reflection finger electrode (271) is a seventh inclined surface (272), the seventh inclined surface (272) being arranged obliquely along the surface acoustic wave propagation direction;
the other end surface of the reflection grating (27) which is far from the reflection finger electrode (271) is an eighth inclined surface (273), and the eighth inclined surface (273) is obliquely arranged along the propagation direction of the surface acoustic wave.
7. The surface acoustic wave resonator (100) according to any of claims 1-5, wherein the interdigital transducer (2) is made of one or more of aluminum, copper, titanium, chromium, silver and nickel.
8. The surface acoustic wave resonator (100) according to any one of claims 1 to 5, wherein the piezoelectric substrate (1) comprises a supporting layer (11), a dielectric layer (12) and a piezoelectric layer (13) which are sequentially arranged, and the interdigital transducer (2) is arranged on the piezoelectric layer (13).
9. The surface acoustic wave resonator (100) according to claim 8, characterized in that the material of the support layer (11) is Si, siC or sapphire; and/or
The material of the dielectric layer (12) is SiO 2 The method comprises the steps of carrying out a first treatment on the surface of the And/or
The piezoelectric layer (13) is made of LiTaO 3 Or LiNbO 3 。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202321024255.2U CN219718197U (en) | 2023-04-26 | 2023-04-26 | Surface acoustic wave resonator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202321024255.2U CN219718197U (en) | 2023-04-26 | 2023-04-26 | Surface acoustic wave resonator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN219718197U true CN219718197U (en) | 2023-09-19 |
Family
ID=87977054
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202321024255.2U Active CN219718197U (en) | 2023-04-26 | 2023-04-26 | Surface acoustic wave resonator |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN219718197U (en) |
-
2023
- 2023-04-26 CN CN202321024255.2U patent/CN219718197U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4613960B2 (en) | Lamb wave device | |
| KR100290204B1 (en) | Multimode surface acoustic wave filter | |
| JP5187444B2 (en) | Surface acoustic wave device | |
| CN110572137A (en) | Acoustic wave device and filtering device | |
| WO2024001757A1 (en) | High-frequency acoustic-wave resonator and filter using same | |
| JP2000244275A (en) | Saw resonator filter | |
| WO2023002858A1 (en) | Elastic wave device and filter device | |
| JPH10261938A (en) | Surface acoustic wave filter | |
| CN116318035A (en) | Surface acoustic wave resonator and wireless communication device | |
| WO2021060509A1 (en) | Elastic wave device | |
| WO2021060508A1 (en) | Elastic wave device | |
| JP7120441B2 (en) | Acoustic wave device | |
| JP5195443B2 (en) | Elastic wave device | |
| JP2000183681A (en) | Surface acoustic wave device | |
| WO2021060510A1 (en) | Elastic wave device | |
| CN219718197U (en) | Surface acoustic wave resonator | |
| CN219980797U (en) | Transverse resonance-inhibiting surface acoustic wave resonator and filter | |
| JP2005012736A (en) | Surface acoustic wave converter and electronic device using same | |
| JPH10145173A (en) | Interdigital transducer and surface acoustic wave multiplex mode filter | |
| JPH11298286A (en) | Surface acoustic wave waveguide structure and device using the structure | |
| WO2023002823A1 (en) | Elastic wave device | |
| CN215871344U (en) | Acoustic wave device and filtering device | |
| CN114710133B (en) | Acoustic longitudinal shear wave resonator based on lithium niobate monocrystal film | |
| JPH09186542A (en) | Surface acoustic wave resonator filter | |
| CN115567022A (en) | Acoustic wave device, filtering device and preparation method of acoustic wave device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |