CN115378398B - Transverse mode suppression electroacoustic transducer - Google Patents
Transverse mode suppression electroacoustic transducer Download PDFInfo
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- CN115378398B CN115378398B CN202211291296.8A CN202211291296A CN115378398B CN 115378398 B CN115378398 B CN 115378398B CN 202211291296 A CN202211291296 A CN 202211291296A CN 115378398 B CN115378398 B CN 115378398B
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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
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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
- H03H9/02—Details
- H03H9/02535—Details of surface acoustic wave devices
- H03H9/02818—Means for compensation or elimination of undesirable effects
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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
- H03H9/02—Details
- H03H9/02535—Details of surface acoustic wave devices
- H03H9/02818—Means for compensation or elimination of undesirable effects
- H03H9/02834—Means for compensation or elimination of undesirable effects of temperature influence
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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
- H03H9/02—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
Abstract
The invention relates to a transverse mode suppression electroacoustic transducer, which comprises a piezoelectric substrate, an interdigital transducer, an intermittent metal strip and a temperature compensation layer, wherein the interdigital transducer is arranged on the piezoelectric substrate; the interdigital transducer comprises a pair of bus bars and two groups of IDT fingers which are arranged at intervals; the distributed area of the IDT finger strips comprises a working area and a gap area, and the gap area is positioned between the working area and the bus bar; the discontinuous metal strips are discontinuously distributed in the slit areas, at least one group of discontinuous metal strips are arranged in each slit area and are respectively connected with the IDT fingers, and the electric polarity flows in through the corresponding IDT fingers connected with the discontinuous metal strips. The invention introduces the discontinuous metal strip structure into the IDT layer, the introduction of the discontinuous metal strip structure changes the waveguide structure of the IDT layer, and under the condition of not increasing the process difficulty, the invention not only optimizes the in-band stray, but also keeps the other performances of the resonator not influenced, and can obviously improve the overall performance of the device.
Description
Technical Field
The invention relates to the technical field of surface acoustic wave resonators, in particular to a transverse mode suppression electroacoustic transducer.
Background
Based on the surface acoustic wave filter, the surface acoustic wave filter has the advantages of low insertion loss, wide bandwidth, small volume, low cost, mass production and the like, and is widely applied to mobile communication equipment; with the development of communication protocols and the increase of the number of frequency bands, the requirements on the electrical performance in the pass band and the suppression outside the pass band of a filter are higher and higher. An optimally designed electroacoustic transducer is particularly important for obtaining a high performance SAW device, since the electroacoustic transducer is a major component of the SAW device.
In the surface acoustic wave resonator, an acoustic wave in a main mode propagates in the width direction of the electrode finger, and the acoustic wave also propagates in the length direction of the electrode finger. The acoustic wave propagates in the length direction of the electrode fingers, so that unnecessary transverse-mode (spurious) stray (spurious) occurs in the frequency characteristic, the spurious response generated by the transverse modes causes fluctuation in a pass band, meanwhile, the energy loss of the SAW device is increased, the Q value of the device is reduced, and the performance of the filter is affected. Therefore, for the influence of such stray modes, a common optimization structure at present is to provide hammerhead structures at two ends of an electrode, that is, thickened (piston structure) or thickened (hammerhead structure) edge regions at two ends of an aperture, and the structure reduces the propagation speed of the hammerhead region by changing the IDT waveguide structure, so that energy is concentrated in the IDT waveguide to the maximum extent, but the suppression of the transverse mode of the device by the hammerhead structure is limited, so that the transverse mode suppression electroacoustic transducer is developed to improve the suppression of the transverse mode of the surface acoustic wave filter, so as to solve the problems in the prior art.
Disclosure of Invention
The invention aims at: the transverse mode suppression electroacoustic transducer is provided to solve the problem that the suppression effect of the transverse stray mode in the surface acoustic wave resonator in the prior art is limited.
The technical scheme of the invention is as follows: a transverse mode suppression electro-acoustic transducer comprising:
a piezoelectric substrate;
the interdigital transducer comprises a pair of bus bars and two groups of IDT fingers which are arranged at intervals alternately; the IDT finger strip distribution area comprises a working area and a gap area, and the gap area is positioned between the working area and the bus bar;
discontinuous metal strips which are discontinuously distributed in the gap areas, at least one group of discontinuous metal strips are arranged in each gap area and are respectively connected with the corresponding IDT finger, and the electric polarity flows in through the connected IDT finger;
and the temperature compensation layer is coated on the interdigital transducer and the discontinuous metal strip.
Preferably, the discontinuous metal strips in the gap areas on the same side are aligned and arranged along a direction perpendicular to the IDT finger strips, and a gap is formed between adjacent discontinuous metal strips, and the gap satisfies the following conditions:
H＜（1.5-0.5*mp）*p，
0.4＜mp＜0.65，
wherein H is a gap between adjacent discontinuous metal strips,
mp is the metallization rate of the IDT fingers,
p is the period of the IDT fingers.
Preferably, the discontinuous metal strips in the gap areas on the same side are arranged in a staggered and parallel manner, and the projection ends of the adjacent discontinuous metal strips in the direction perpendicular to the IDT finger are aligned, overlapped or disconnected.
Preferably, the discontinuous metal strips in the slit areas on the same side are arranged in parallel along the inclined direction, two end parts of the discontinuous metal strips are parallel to the direction of the IDT finger strips, and the projection end parts of the adjacent discontinuous metal strips in the direction perpendicular to the IDT finger strips are aligned, overlapped or disconnected.
Preferably, at least one finger electrode is arranged between the discontinuous metal strip and the bus bar in the gap area on the same side.
Preferably, at least one finger prosthesis electrode is respectively arranged on the side edges of the IDT finger strips in the gap areas on the same side, and the end parts of the finger prosthesis electrodes are connected with metal parts; the metal part on the fake finger electrode and the discontinuous metal strip on the IDT finger strip are distributed discontinuously.
Preferably, the width DMS =0.25p to 1.0p of the discontinuous metal strips distributed discontinuously along the direction of the IDT finger;
the distance between the discontinuous metal strip and the end part of another group of IDT finger strips is d2=0.15 p-1.0 p;
wherein p is the period of the IDT finger.
Preferably, the areas of the two groups of IDT fingers which are alternately distributed at intervals are working areas, and the areas which are not alternately distributed at intervals are gap areas; the IDT finger strips are respectively provided with a suppression structure corresponding to two ends of the working area, and the suppression structures are combined with discontinuous metal strips to jointly play a role in adjusting sound velocity of each part for suppressing transverse mode;
the inhibition structure comprises a hammerhead structure and/or a piston structure.
Preferably, the temperature compensation layer is made of a material with a positive frequency temperature coefficient, and is made of any one or a combination of more of silicon dioxide, tellurium dioxide and silicon oxyfluoride.
Compared with the prior art, the invention has the advantages that:
(1) The invention introduces the discontinuous metal strip structure into the IDT layer, the introduction of the discontinuous metal strip structure changes the waveguide structure of the IDT layer, and under the condition of not increasing the process difficulty, the invention not only optimizes the in-band stray, but also keeps the other performances of the resonator not influenced, and can obviously improve the overall performance of the device.
(2) Based on simulation analysis, the addition of the discontinuous metal strips can effectively inhibit in-band spurious emission and simultaneously not deteriorate out-of-band modes; for the intermittent metal strips which are arranged in a staggered mode, certain bandwidth can be increased.
Drawings
The invention is further described below with reference to the following figures and examples:
fig. 1 is a schematic structural diagram of an electroacoustic transducer with transverse mode suppression according to embodiment 1 of the present invention;
fig. 2 is a schematic structural view of an interdigital transducer in accordance with embodiment 1 of the present invention;
fig. 3 is a diagram of a comparative simulation result of the absolute values of the admittance curves of the transverse mode suppression electroacoustic transducer and the conventional resonator according to embodiment 1 of the present invention;
fig. 4 is a graph of a comparative simulation result of real parts of admittance curves of a transverse mode suppression electroacoustic transducer according to embodiment 1 of the present invention and a conventional resonator;
fig. 5 is a diagram of a comparative simulation result of the imaginary part of the admittance curves of the transverse mode suppression electroacoustic transducer according to embodiment 1 of the present invention and a conventional resonator;
fig. 6 is a schematic structural diagram of an electroacoustic transducer with transverse mode suppression according to embodiment 2 of the present invention;
fig. 7 is a schematic structural view of an interdigital transducer in embodiment 2 of the present invention;
fig. 8 is a graph of a simulation result comparing absolute values of admittance curves of a transverse mode suppression electroacoustic transducer according to embodiment 2 of the present invention with a conventional resonator;
fig. 9 is a graph of a comparative simulation result of real parts of admittance curves of a transverse mode suppression electroacoustic transducer according to embodiment 2 of the present invention and a conventional resonator;
fig. 10 is a graph of comparative simulation results of the imaginary part of the admittance curves of the transverse mode suppression electroacoustic transducer according to embodiment 2 of the present invention and a conventional resonator;
fig. 11 is a schematic structural diagram of an electroacoustic transducer with transverse mode suppression according to embodiment 3 of the present invention;
fig. 12 is a graph of the comparative simulation result of the absolute values of the admittance curves of the transverse mode suppression electroacoustic transducer according to embodiment 3 of the present invention and the conventional resonator;
fig. 13 is a graph of a comparative simulation result of real parts of admittance curves of a transverse mode suppression electroacoustic transducer according to embodiment 3 of the present invention and a conventional resonator;
fig. 14 is a graph of comparative simulation results of the imaginary part of the admittance curves of the transverse mode suppression electroacoustic transducer according to embodiment 3 of the present invention and a conventional resonator;
fig. 15 is a schematic structural diagram of an electroacoustic transducer with transverse mode suppression according to embodiment 4 of the present invention;
fig. 16 is a schematic structural diagram of an electroacoustic transducer with transverse mode suppression according to embodiment 5 of the present invention;
fig. 17 is a schematic structural diagram of a transverse mode suppression electroacoustic transducer according to embodiment 6 of the present invention;
fig. 18 is a schematic structural diagram of an electroacoustic transducer with transverse mode suppression according to embodiment 7 of the present invention;
fig. 19 is a schematic structural diagram of an electroacoustic transducer with transverse mode suppression according to embodiment 8 of the present invention;
fig. 20 is a schematic structural diagram of an electroacoustic transducer with transverse mode suppression according to embodiment 9 of the present invention.
Wherein:
1. a piezoelectric substrate;
2. an interdigital transducer, 21, a bus bar, 22, an IDT finger, 23, a hammerhead structure, 24, a piston structure, 25, a fake finger electrode, 26 and a metal part;
3. a discontinuous metal strip;
4. a temperature compensation layer.
Detailed Description
The present invention will be further described in detail with reference to the following specific examples:
[ example 1 ] A method for producing a polycarbonate
As shown in fig. 1, an electroacoustic transducer with transverse mode suppression includes a piezoelectric substrate 1, an interdigital transducer 2, an intermittent metal strip 3, and a temperature compensation layer 4; the invention is used for configuring and generating surface acoustic waves, and is based on the interrupted metal strip 3 additionally arranged in the traditional structure, and is used for inhibiting unnecessary transverse mode spurs generated by the propagation of the surface acoustic waves in the length direction of the IDT finger 22.
The piezoelectric substrate 1 is used as a substrate structure, and the material thereof can be quartz, aluminum nitride, LN (lithium niobate, liNbO) 3 ) LT (lithium tantalate, liTaO) 3 ) Etc., the acoustic wave propagates at the surface or interface of the piezoelectric substrate 1.
Based on SAW (surface acoustic wave) devices are susceptible to temperature variation, so that the device can be improved by coating a layer of temperature compensation material with a positive frequency temperature coefficient; the temperature compensation layer 4 is coated on the interdigital transducer 2 and the discontinuous metal strip 3, and can be any one or combination of more of silicon dioxide, tellurium dioxide and silicon oxyfluoride.
An interdigital transducer 2 (IDT) is deposited on the piezoelectric substrate 1, is the most basic unit of the surface acoustic wave, and comprises a pair of bus bars 21 arranged oppositely at intervals and two groups of IDT fingers 22 arranged at intervals; two sets of IDT fingers 22 extend from one side bus bar 21 to the other side bus bar 21, and the distribution area of IDT fingers 22 includes a working area and a gap area, wherein the area where two sets of IDT fingers 22 are alternately distributed at intervals is the working area, the area where the two sets of IDT fingers are not alternately distributed at intervals is the gap area, and the gap area is located between the working area and the bus bar 21.
The discontinuous metal strips 3 are discontinuously distributed in the slit areas, at least one group of discontinuous metal strips 3 are arranged in each slit area and are respectively connected with the IDT fingers 22, and the electric polarity flows in through the connected IDT fingers 22; by additionally arranging the intermittent metal strips 3, on one hand, the electric field distribution of the resonator is changed in an electrical mode, so that the transverse mode is inhibited; on the other hand, the gap structure topological distribution between the IDT finger 22 and the bus bar 21 is adjusted, so that the sound velocity distribution of the gap region is changed, and the transverse mode is restrained; in this embodiment, a group of intermittent metal strips 3 are disposed in the gap area on the same side, the intermittent metal strips 3 are aligned and arranged in a direction perpendicular to the IDT finger 22, and a gap is formed between adjacent intermittent metal strips 3. As a further optimization, the two ends of the IDT finger 22 corresponding to the working area are respectively provided with a suppression structure, i.e. the IDT finger 22 is thickened to form a hammerhead structure 23, and the metallization rate of the hammerhead structure 23 is not too high, so as to avoid short circuit between adjacent IDT fingers 22.
Referring to fig. 2, the period of the IDT finger 22 is set as p, and the relevant design parameters in this embodiment are as follows:
| design parameters | Parameter value |
| IDT finger strip metallization rate mp | 0.4～0.65 |
| IDT finger width a | p*mp |
| Distance b between adjacent IDT fingers in the operating region | p-p*mp |
| Width c of bus bar | 2.5p±0.2p |
| Length wa of hammerhead structure | 1.0p～2.5p |
| Width wb of hammerhead structure | 0.45p～0.80p |
| Metallization ratio HDF of hammerhead structure | wb/p=0.45～0.80 |
| Intermittent metal strip width DMS | 0.25p～1.0p |
| Distance d2 between discontinuous metal strip and IDT finger end | 0.15p～1.0p |
| Gap H between adjacent discontinuous metal strips | 0.5*（1-HDF）*p～（1.5-0.5*mp）*p |
In this embodiment, within the reasonable range of the width DMS of the discontinuous metal strip 3, the discontinuous metal strips 3 distributed discontinuously may adopt topological distributions with different widths; the distance d2 from the end of the IDT finger 22 is one of the key parameters for suppressing transverse modes.
As shown in fig. 3 to fig. 5, the suppression structure (hammerhead structure 23) and the discontinuous metal strips 3 distributed discontinuously are combined to jointly play a role in adjusting sound velocity of each part for suppressing transverse mode.
Referring to the absolute value of the admittance curve, as shown in fig. 3, the conventional resonator without the discontinuous metal strip 3 exhibits a non-smooth glitch between the resonance point and the anti-resonance point due to the excitation of the transverse mode, while the admittance curve becomes smooth by the addition of the discontinuous metal strip 3, demonstrating an effective suppression of in-band spurious without deteriorating the out-of-band modes.
As shown in fig. 4, the improved resonator has a greatly reduced interference in the admittance curve with reference to the real part of the admittance curve, and the excitation of the transverse mode at this frequency is suppressed by more than 15dB, taking the frequency of about 905MHz as an example.
Referring to the imaginary part of the admittance curve, similar to the absolute value of the admittance curve, for example at frequencies around 895MHz, 905MHz, the conventional resonator has spikes in the imaginary part of the admittance due to the excitation of transverse modes, whereas the transverse modes between the resonance point and the antiresonance point of the resonator with a set of discontinuous metal strips 3 are significantly improved, as shown in fig. 5.
[ example 2 ]
As shown in fig. 6, a transverse mode suppression electroacoustic transducer includes a piezoelectric substrate 1, an interdigital transducer 2 and a discontinuous metal strip 3 deposited on the piezoelectric substrate 1, and a temperature compensation layer 4 coated on the interdigital transducer 2 and the discontinuous metal strip 3.
The present embodiment is different from embodiment 1 in that: as shown in fig. 7, the discontinuous metal strips 3 in the gap areas on the same side are arranged in parallel and staggered, and the projection ends of the adjacent discontinuous metal strips 3 in the direction perpendicular to the IDT finger 22 are aligned (at t 2), overlapped (at t 3) or disconnected (at t 1); wherein:
the distance d2 between any intermittent metal strip 3 and the end part of the IDT finger strip 22 satisfies 0.15p < d2 < 1.0p;
the width DMS of the discontinuous metal strip 3 satisfies that DMS is more than 0.25p and less than 1.0p;
the widths of a group of discontinuous metal strips 3 corresponding to the same side gap area can be equal or topological distribution with different widths is adopted.
As shown in fig. 8 to 10, in combination with the comparison of the absolute value, the real part and the imaginary part of the admittance curves corresponding to the conventional resonator and the resonator of the present invention, the transverse mode between the resonance point and the anti-resonance point of the resonator with the intermittent and staggered parallel arrangement of the intermittent metal strips 3 is almost completely suppressed compared to the resonator without the intermittent metal strips 3; meanwhile, compared with the embodiment 1, in the embodiment, under the condition of effectively inhibiting the in-band spurious, the out-of-band spurious is further inhibited, and the bandwidth is increased on the basis of the transverse mode inhibition; thus, the suppression effect of the transverse mode in example 2 is slightly better than that in example 1.
[ example 3 ]
As shown in fig. 11, a transverse mode suppression electroacoustic transducer includes a piezoelectric substrate 1, an interdigital transducer 2 and a discontinuous metal strip 3 deposited on the piezoelectric substrate 1, and a temperature compensation layer 4 coated on the interdigital transducer 2 and the discontinuous metal strip 3.
The present embodiment is different from embodiment 1 in that: as shown in fig. 11, two sets of discontinuous metal strips 3 are disposed in the gap region on the same side, each set of discontinuous metal strips 3 are aligned and arranged along a direction perpendicular to the IDT finger 22, and a gap is formed between adjacent discontinuous metal strips 3; wherein, the first and the second end of the pipe are connected with each other,
the distance d2 between any discontinuous metal strip 3 connected with the same IDT finger strip 22 and the end part of another group of IDT finger strips 22 satisfies 0.15p < d2 < 1.0p;
the width DMS of the discontinuous metal strips 3 meets the condition that DMS is more than 0.25p and less than 1.0p, and the widths of a group of discontinuous metal strips 3 corresponding to the same side gap area can be equal or topological distribution with different widths is adopted;
the gaps between at least one group of intermittent metal strips 3 satisfy 0.5 x (1-HDF) p < H < (1.5-0.5 mp).
As shown in fig. 12-14, the transverse mode between the resonance point and the anti-resonance point of the resonator with multiple sets of discontinuous metal strips 3 is almost completely suppressed compared to the resonator without discontinuous metal strips 3 by simulation analysis.
[ example 4 ]
As shown in fig. 15, an electroacoustic transducer with transverse mode suppression includes a piezoelectric substrate 1, an interdigital transducer 2 and a discontinuous metal strip 3 deposited on the piezoelectric substrate 1, and a temperature compensation layer 4 coated on the interdigital transducer 2 and the discontinuous metal strip 3.
The present example is different from example 1 in that: as for the discontinuous metal strips 3, as shown in fig. 15, the discontinuous metal strips 3 in the same-side slit region are arranged in parallel in the oblique direction, both end portions are parallel to the direction of the IDT finger 22, and the projection end portions of the adjacent discontinuous metal strips 3 in the direction perpendicular to the direction of the IDT finger 22 are aligned, overlapped or disconnected; wherein:
the distance d2 between any one of the discontinuous metal strips 3 and the end of another set of IDT finger strips 22 satisfies 0.15p < d2 < 1.0p.
[ example 5 ]
As shown in fig. 16, a transverse mode suppression electroacoustic transducer includes a piezoelectric substrate 1, an interdigital transducer 2 and a discontinuous metal strip 3 deposited on the piezoelectric substrate 1, and a temperature compensation layer 4 coated on the interdigital transducer 2 and the discontinuous metal strip 3.
The present embodiment is different from embodiment 1 in that: regarding the discontinuous metal strips 3 and the suppression structure, a group of discontinuous metal strips 3 are arranged in the gap area on the same side, the discontinuous metal strips 3 are aligned and arranged along the direction vertical to the IDT finger 22, and a gap is formed between adjacent discontinuous metal strips 3. The IDT finger 22 is provided with a suppressing structure corresponding to each end of the operating region, which is a thickened piston structure 24.
[ example 6 ] A method for producing a polycarbonate
As shown in fig. 17, an electroacoustic transducer with transverse mode suppression includes a piezoelectric substrate 1, an interdigital transducer 2 and a discontinuous metal strip 3 deposited on the piezoelectric substrate 1, and a temperature compensation layer 4 coated on the interdigital transducer 2 and the discontinuous metal strip 3.
The present embodiment is different from embodiment 2 in that: regarding the discontinuous metal strips 3 and the suppression structure, the discontinuous metal strips 3 in the gap area on the same side are staggered and arranged in parallel, and the projection ends of the adjacent discontinuous metal strips 3 in the direction perpendicular to the IDT finger 22 are aligned, overlapped or disconnected. The IDT finger 22 is provided with a suppressing structure corresponding to each end of the operating region, which is a thickened piston structure 24.
[ example 7 ]
As shown in fig. 18, a transverse mode suppression electroacoustic transducer includes a piezoelectric substrate 1, an interdigital transducer 2 and a discontinuous metal strip 3 deposited on the piezoelectric substrate 1, and a temperature compensation layer 4 coated on the interdigital transducer 2 and the discontinuous metal strip 3.
The present embodiment is different from embodiment 1 in that: a group of discontinuous metal strips 3 are arranged in the gap area on the same side, the discontinuous metal strips 3 are aligned and arranged along the direction vertical to the IDT finger strips 22, and gaps are formed between the adjacent discontinuous metal strips 3. At least one dummy finger electrode 25 is disposed between the interrupted metal strip 3 and the bus bar 21 in the same-side slit region, and the arrangement direction of the dummy finger electrode 25 is parallel to the length direction of the IDT finger 22.
[ example 8 ]
As shown in fig. 19, an electroacoustic transducer with transverse mode suppression includes a piezoelectric substrate 1, an interdigital transducer 2 and a discontinuous metal strip 3 deposited on the piezoelectric substrate 1, and a temperature compensation layer 4 coated on the interdigital transducer 2 and the discontinuous metal strip 3.
The present embodiment is different from embodiment 2 in that: the discontinuous metal strips 3 in the gap areas on the same side are arranged in a staggered and parallel manner, and the projection ends of the adjacent discontinuous metal strips 3 in the direction vertical to the IDT finger 22 are aligned, overlapped or disconnected. At least one dummy finger electrode 25 is arranged between the interrupted metal bar 3 and the bus bar 21 in the same side gap area, and the arrangement direction of the dummy finger electrode 25 is parallel to the length direction of the IDT finger 22.
[ example 9 ]
As shown in fig. 20, an electroacoustic transducer with transverse mode suppression includes a piezoelectric substrate 1, an interdigital transducer 2 and a discontinuous metal strip 3 deposited on the piezoelectric substrate 1, and a temperature compensation layer 4 coated on the interdigital transducer 2 and the discontinuous metal strip 3.
The present embodiment is different from embodiment 1 in that: at least one fake finger electrode 25 is arranged on the side edge of the IDT finger strip 22 in the gap area on the same side, and the end part of the fake finger electrode 25 is connected with a metal part 26; the metal portion 26 on the finger electrode 25 is not continuous with the discontinuous metal strip 3 on the IDT finger 22.
The above-described embodiments 4 to 9 are further optimized in the embodiments 1 and 2, and the suppression effects of the embodiments 4 to 9 are also very significant when the embodiments 1 and 2 have a sufficient suppression effect on the transverse mode.
The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose of the embodiments is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore intended that the present embodiments be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
Claims (6)
1. A transverse mode suppression electro-acoustic transducer, comprising:
a piezoelectric substrate;
the interdigital transducer comprises a pair of bus bars and two groups of IDT fingers which are arranged at intervals alternately; the IDT finger distribution area comprises a working area and a gap area, the area where the two groups of IDT fingers are alternately distributed at intervals is the working area, the area where the two groups of IDT fingers are not alternately distributed at intervals is the gap area, and the gap area is positioned between the working area and the bus bar;
discontinuous metal strips are discontinuously distributed in the gap areas, and at least one group of discontinuous metal strips are arranged in each gap area and are respectively connected with the corresponding IDT finger strips; the discontinuous metal strips in the gap areas on the same side are arranged in a staggered and parallel mode, and the projection end parts of the adjacent discontinuous metal strips in the direction perpendicular to the IDT finger strips are aligned, overlapped or disconnected;
and the temperature compensation layer is coated on the interdigital transducer and the discontinuous metal strip.
2. A transverse mode suppression electro-acoustic transducer according to claim 1, wherein: at least one fake finger electrode is arranged between the discontinuous metal strip and the bus bar in the gap area on the same side.
3. A transverse mode suppressing electro-acoustic transducer as claimed in claim 1, characterized by: at least one fake finger electrode is arranged on the side edge of the IDT finger strip in the gap area on the same side, and the end part of the fake finger electrode is connected with a metal part; the metal part on the fake finger electrode and the discontinuous metal strip on the IDT finger strip are distributed discontinuously.
4. A transverse mode suppressing electro-acoustic transducer as claimed in any one of claims 2 to 3, characterized by: the width DMS =0.25 p-1.0 p of the discontinuous metal strips distributed discontinuously along the IDT finger strip direction;
the distance between the discontinuous metal strip and the end part of another group of IDT finger strips is d2=0.15 p-1.0 p;
wherein p is the period of the IDT finger.
5. A transverse mode suppressing electro-acoustic transducer as claimed in any one of claims 2 to 3, characterized by: the IDT finger strips are respectively provided with a suppression structure corresponding to two ends of the working area, and the suppression structures are combined with discontinuous metal strips to jointly play a role in adjusting sound velocity of each part for suppressing transverse mode;
the restraining structure includes a hammer head structure and/or a plunger structure.
6. A transverse mode suppression electro-acoustic transducer according to claim 1, wherein: the temperature compensation layer is made of a material with a positive frequency temperature coefficient, and is made of any one or a combination of more of silicon dioxide, tellurium dioxide and silicon oxyfluoride.
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| CN116032242B (en) * | 2023-03-30 | 2023-08-25 | 阿尔伯达(苏州)科技有限公司 | Surface acoustic wave resonator with parasitic mode suppression layer |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2015056746A (en) * | 2013-09-11 | 2015-03-23 | 株式会社村田製作所 | Acoustic wave device |
| DE102019107011A1 (en) * | 2019-03-19 | 2020-09-24 | RF360 Europe GmbH | 11-IDT DMS filter, electroacoustic filter and multiplexer |
| CN112713873A (en) * | 2020-12-29 | 2021-04-27 | 中国电子科技集团公司第二十六研究所 | Surface acoustic wave filter with multilayer thin film structure |
| CN113824423A (en) * | 2021-09-13 | 2021-12-21 | 江苏卓胜微电子股份有限公司 | Transducer structure for improving Q value and inhibiting transverse mode and surface acoustic wave resonator |
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| JP3315646B2 (en) * | 1998-06-19 | 2002-08-19 | 富士通株式会社 | Surface acoustic wave filter |
| US11870421B2 (en) * | 2019-10-23 | 2024-01-09 | Skyworks Solutions, Inc. | Surface acoustic wave resonator with suppressed transverse modes using second bus bar |
| WO2022134195A1 (en) * | 2020-12-23 | 2022-06-30 | 杭州左蓝微电子技术有限公司 | Surface acoustic wave resonator and manufacturing method therefor |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2015056746A (en) * | 2013-09-11 | 2015-03-23 | 株式会社村田製作所 | Acoustic wave device |
| DE102019107011A1 (en) * | 2019-03-19 | 2020-09-24 | RF360 Europe GmbH | 11-IDT DMS filter, electroacoustic filter and multiplexer |
| CN112713873A (en) * | 2020-12-29 | 2021-04-27 | 中国电子科技集团公司第二十六研究所 | Surface acoustic wave filter with multilayer thin film structure |
| CN113824423A (en) * | 2021-09-13 | 2021-12-21 | 江苏卓胜微电子股份有限公司 | Transducer structure for improving Q value and inhibiting transverse mode and surface acoustic wave resonator |
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