Resonator and surface acoustic wave filter

Abstract

The invention relates to the technical field of filters, and discloses a resonator and a surface acoustic wave filter, and the resonator comprises an interdigital transducer and a transverse strip structure. The interdigital transducer comprises a first bus bar, a second bus bar, a plurality of first finger bars and a plurality of second finger bars; the first bus bar and the second bus bar are oppositely arranged, the same ends of the plurality of first finger bars are connected with one side, close to the second bus bar, of the first bus bar, and the same ends of the plurality of second finger bars are connected with one side, close to the first bus bar, of the second bus bar; the transverse strip structure is arranged in a target area of the interdigital transducer; the transverse strip structure comprises a plurality of first transverse strips and a plurality of second transverse strips, the first transverse strips and the second transverse strips are arranged in a crossed mode, the adjacent first transverse strips and second transverse strips are distributed in a staggered mode, and the first ends, in the first direction, of the first transverse strips are connected with the third ends, in the first direction, of the second transverse strips. According to the resonator provided by the invention, the Q value of the resonator can be improved while a transverse mode is effectively suppressed.

Description

TECHNICAL FIELD

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

[0002] The filter can effectively filter out or eliminate the frequency band of a specific frequency or a frequency other than the specific frequency, and is a key device of a communication system. With the development of communication technology, the requirements for the filter are becoming higher and higher. The surface acoustic wave (SAW) filter has the advantages of low insertion loss, wide bandwidth and small size, and has been widely used in radio frequency front-end circuits. However, various spurious modes (such as transverse modes) exist in the surface acoustic wave filter, which seriously affects the performance of the resonator. Therefore, suppressing the transverse mode is of great significance to the performance improvement of the surface acoustic wave filter.

[0003] In the related art, the length of the area directly opposite to the finger is changed by apodization weighting or finger extraction weighting on the relative area of the metal finger (hereinafter referred to as finger) of the interdigital transducer (IDT), so as to achieve the purpose of suppressing the excitation and generation of the transverse mode. Although this method is simple and easy to implement, it will reduce the quality factor and electrode coupling coefficient of the filter, and also cause the increase of the size of the device. SUMMARY

[0004] Therefore, the present application provides a resonator and a surface acoustic wave filter to solve the problem of affecting the performance of the resonator while suppressing the transverse mode.

[0005] In a first aspect, the present application provides a resonator, which comprises an interdigital transducer and a horizontal bar structure; the interdigital transducer comprises a first bus bar, a second bus bar, a plurality of first fingers and a plurality of second fingers; wherein the first bus bar and the second bus bar are oppositely arranged, the same end of the plurality of first fingers is connected to the side of the first bus bar close to the second bus bar, the same end of the plurality of second fingers is connected to the side of the second bus bar close to the first bus bar, and the plurality of first fingers and the plurality of second fingers are arranged in a first direction, the first direction being the length direction of the first bus bar; the horizontal bar structure is arranged in a target area of the interdigital transducer; wherein the horizontal bar structure comprises a plurality of first horizontal bars and a plurality of second horizontal bars, the plurality of first horizontal bars and the plurality of second horizontal bars are arranged in a cross manner, adjacent first horizontal bars and second horizontal bars are distributed in a staggered manner, and the first end of the first horizontal bar in the first direction is connected to the third end of the second horizontal bar in the first direction; in a direction perpendicular to the first direction, the center line of the interdigital transducer between the inner side of the first bus bar and the inner side of the second bus bar is divided into an effective aperture area, a gap area and a target area in sequence from both sides.

[0006] The resonator provided by the present invention has a horizontal stripe structure arranged in the false finger area of ​​the interdigital transducer. The horizontal stripe structure can form waveguides of different sizes with the fingers of adjacent interdigital transducers, changing the distribution of the electric field at the ends of the fingers, so that there is a sudden change in the electric field distribution between two adjacent fingers, which has the effect of suppressing the propagation of the transverse wave mode. In addition, the horizontal stripe structure can reflect the laterally propagating sound waves, limiting more energy to propagate between the interdigital transducers, reducing the energy that escapes, and can significantly improve the Q value of the resonator, thereby improving the performance of the resonator.

[0007] In an optional embodiment, the effective aperture area is the overlapping area of ​​multiple first fingers and multiple second fingers, the length of the gap area in the direction perpendicular to the first direction ranges from the width of the target horizontal bar to 0.5λ, the length of the area between the inner side of the target bus bar and the effective aperture area in the direction perpendicular to the first direction ranges from 1λ to 2λ, the width of the target horizontal bar is less than or equal to 0.7um, or the width of the target horizontal bar is greater than or equal to 0.28um, λ is the wavelength of the surface acoustic wave, the target horizontal bar is the first horizontal bar or the second horizontal bar, and the target bus bar includes the first bus bar and / or the second bus bar.

[0008] In an optional embodiment, the length direction of the first horizontal bar and the length direction of the second horizontal bar are both perpendicular to the length direction of the first finger bar.

[0009] In an optional embodiment, the first horizontal bar and the second horizontal bar are both rectangular structures, and adjacent first horizontal bars and second horizontal bars in the horizontal bar structure are distributed in a Z-shaped structure.

[0010] In an optional embodiment, the second end of the first horizontal bar in the first direction and / or the fourth end of the second horizontal bar in the first direction are in contact with the target finger bar, and the target finger bar includes the first finger bar or the second finger bar; and / or the second end of the first horizontal bar in the first direction is connected to the fifth end of the third horizontal bar in the first direction, wherein the third horizontal bar is another second horizontal bar adjacent to the first horizontal bar among the multiple second horizontal bars.

[0011] In an optional embodiment, a plurality of first horizontal bars and a plurality of second horizontal bars are arranged in sequence, the length of the first horizontal bars and the length of the second horizontal bars are greater than the width of the target fingers, at least part of the first horizontal bars and at least part of the second horizontal bars are arranged in the gaps between the target fingers, and at least part of the first horizontal bars and at least part of the second horizontal bars are arranged on the target fingers; and / or, part of at least one first horizontal bar is arranged on the target fingers, and another part is arranged in the gaps between the target fingers, and part of at least one second horizontal bar is arranged on the target fingers, and another part is arranged in the gaps between the target fingers.

[0012] In an optional embodiment, the first horizontal bars and the second horizontal bars are arranged in sequence, the length of the first horizontal bars and the length of the second horizontal bars are less than or equal to the width of the target finger bar, at least part of the first horizontal bars or at least part of the second horizontal bars are arranged on the target finger bar or in the gap between the target finger bars; and / or, part of the at least one first horizontal bar is arranged on the target finger bar and part of the at least one first horizontal bar is arranged in the gap between the target finger bars, part of the at least one second horizontal bar is arranged on the target finger bar and part of the at least one second horizontal bar is arranged in the gap between the target finger bars.

[0013] In an optional embodiment, the length of the first horizontal bars and the length of the second horizontal bars are the width of the target finger bar, the distance between the same side of the two adjacent first finger bars, the distance between the same side of the two adjacent second finger bars, or the distance between the two sides of the adjacent first finger bar and the second finger bar away from each other.

[0014] In an optional embodiment, the horizontal bar structure further comprises a plurality of strip structures, one end of the first horizontal bar in the first direction is connected to one end of the second horizontal bar in the first direction through the strip structure.

[0015] In the embodiment, the one end of the first horizontal bar in the first direction is connected to the one end of the second horizontal bar in the first direction through the strip structure, which can ensure the connection of the one end of the first horizontal bar in the first direction to the one end of the second horizontal bar in the first direction, and improve the structural stability of the interdigital transducer.

[0016] In an optional embodiment, the interdigital transducer further comprises a plurality of third finger bars and a plurality of fourth finger bars, the same end of the plurality of third finger bars is connected to the side of the first bus bar close to the second bus bar, and the plurality of third finger bars and the plurality of second finger bars are oppositely arranged, the same end of the plurality of fourth finger bars is connected to the side of the second bus bar close to the first bus bar, and the plurality of fourth finger bars and the plurality of first finger bars are oppositely arranged, and the target finger bar further comprises the third finger bar or the fourth finger bar.

[0017] In the embodiment, the first finger bar and the second finger bar can be true fingers, and the third finger bar and the fourth finger bar can be false fingers. The interdigital transducer comprising the false fingers and the true fingers forms a capacitive sensor structure, when the external mechanical quantity acts on the true finger, the displacement of the true finger is caused, thereby changing the capacitance value between the true finger and the false finger, and further generating an electrical signal. The interdigital transducer comprising the false fingers can increase the sensitivity and the linearity, and reduce the common mode interference to the mechanical quantity.

[0018] In an alternative embodiment, the distance between the side of the first target horizontal strip close to the second bus bar and the end of the corresponding third finger strip away from the first bus bar is greater than or equal to 0, wherein the first target horizontal strip is the second horizontal strip close to the first bus bar among the plurality of second horizontal strips; and the distance between the side of the second target horizontal strip close to the first bus bar and the end of the corresponding fourth finger strip away from the second bus bar is greater than or equal to 0, wherein the second target horizontal strip is the first horizontal strip close to the second bus bar among the plurality of first horizontal strips.

[0019] In a second aspect, the present application provides a surface acoustic wave filter, comprising: at least one resonator of the first aspect or any of the corresponding embodiments, a piezoelectric material layer and a substrate; the piezoelectric material layer covers the upper surface of the substrate, and the at least one resonator is located on the upper surface of the piezoelectric material layer.

[0020] In the embodiment, the resonator provided by the above embodiment is used to form a surface acoustic wave filter, which can effectively reduce the insertion loss of the filter, reduce the ripple in the passband, improve the rectangularity of the filter, and further improve the performance of the filter. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the specific embodiments or related art, the following will briefly introduce the drawings needed to be used in the specific embodiments or related art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0022] Figure 1 is a structural schematic diagram of a conventional resonator;

[0023] Figure 2 is a schematic diagram of the admittance curve of a conventional resonator;

[0024] Figure 3 is a structural schematic diagram of a first interdigital transducer with horizontal strip structure according to an embodiment of the present application;

[0025] Figure 4 is a structural schematic diagram of the effective aperture region, gap region and target region of an interdigital transducer according to an embodiment of the present application;

[0026] Figure 5a is a schematic diagram of the correspondence between the frequency and the imaginary part of admittance of an interdigital transducer with or without horizontal strip structure according to an embodiment of the present application;

[0027] Figure 5b is a schematic diagram of the correspondence between the frequency and the real part of admittance of an interdigital transducer with or without horizontal strip structure according to an embodiment of the present application;

[0028] Figure 6a is a diagram showing the correspondence between the frequency and the Q value of the interdigital transducer with the horizontal bar structure according to the embodiment of the present application;

[0029] Figure 6b is a diagram showing the correspondence between the frequency and the phase of the admittance amplitude value of the interdigital transducer with the horizontal bar structure according to the embodiment of the present application;

[0030] Figure 7 is a diagram showing the structure of a second interdigital transducer with the horizontal bar structure according to the embodiment of the present application;

[0031] Figure 8 is a diagram showing the structure of a third interdigital transducer with the horizontal bar structure according to the embodiment of the present application;

[0032] Figure 9 is a diagram showing the structure of a fourth interdigital transducer with the horizontal bar structure according to the embodiment of the present application;

[0033] Figure 10 is a diagram showing the structure of a fifth interdigital transducer with the horizontal bar structure according to the embodiment of the present application;

[0034] Figure 11 is a diagram showing the structure of a sixth interdigital transducer with the horizontal bar structure according to the embodiment of the present application;

[0035] Figure 12 is a diagram showing the structure of a seventh interdigital transducer with the horizontal bar structure according to the embodiment of the present application;

[0036] Figure 13 is a diagram showing the structure of an eighth interdigital transducer with the horizontal bar structure according to the embodiment of the present application;

[0037] Figure 14 is a diagram showing the structure of a ninth interdigital transducer with the horizontal bar structure according to the embodiment of the present application;

[0038] Figure 15 is a diagram showing the structure of a tenth interdigital transducer with the horizontal bar structure according to the embodiment of the present application;

[0039] Figure 16 is a diagram showing the structure of an eleventh interdigital transducer with the horizontal bar structure according to the embodiment of the present application;

[0040] Figure 17 is a diagram showing the structure of a twelfth interdigital transducer with the horizontal bar structure according to the embodiment of the present application;

[0041] Figure 18 is a diagram showing the structure of a twelfth interdigital transducer with the horizontal bar structure according to the embodiment of the present application;

[0042] Figure 19 is a structural schematic diagram of a thirteenth structure of setting a horizontal bar structure in an interdigital transducer according to an embodiment of the present application;

[0043] Figure 20 is a structural schematic diagram of a fourteenth structure of setting a horizontal bar structure in an interdigital transducer according to an embodiment of the present application;

[0044] Figure 21 is a structural schematic diagram of a fifteenth structure of setting a horizontal bar structure in an interdigital transducer according to an embodiment of the present application;

[0045] Figure 22 is a structural schematic diagram of a sixteenth structure of setting a horizontal bar structure in an interdigital transducer according to an embodiment of the present application;

[0046] Figure 23 is a structural schematic diagram of a metal duty cycle according to an embodiment of the present application;

[0047] Figure 24 is a structural schematic diagram of a surface acoustic wave filter according to an embodiment of the present application.

[0048] Reference signs: 100, resonator; 110, interdigital transducer; 111, first bus bar; 112, second bus bar; 113, first finger; 114, second finger; 115, third finger; 116, fourth finger; 120, horizontal bar structure; 121, first horizontal bar; 122, second horizontal bar; 123, bar structure; 130, effective reflection grid; 200, piezoelectric material layer; 300, substrate; 310, first substrate layer; 320, second substrate layer. DETAILED DESCRIPTION

[0049] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0050] With the development of technology, the types of filters are also more and more, from the filter circuit network composed of filter inductance, filter capacitance and resistance, to the cavity resonator, from the ceramic resonator (Low Temperature Co-fired Ceramic, LTCC) to the surface acoustic wave filter. Since entering the Long Term Evolution (LTE) era, the surface acoustic wave filter has become more and more important in the communication system. At the same time, with the development of communication technology, the requirements for the filter are also getting higher and higher, especially with the advent of the 5th-Generation (5G) mobile communication technology, the filter industry is facing major challenges and opportunities.

[0051] The surface acoustic wave filter has the advantages of low insertion loss, wide bandwidth, small size, etc., and has been widely used in radio frequency front-end circuits. However, the resonator used to form the conventional surface acoustic wave filter has various spurious modes, which seriously affects the performance of the resonator and in turn affects the performance of the surface acoustic wave filter. The transverse mode (also known as the transverse wave mode) is one of the main spurious modes, so suppressing the transverse mode is of great significance to the performance improvement of the surface acoustic wave filter.

[0052] Specifically, as shown in Figure 1 The conventional resonator is composed of an interdigital transducer 110 and effective reflection gratings 130 located on both sides of the interdigital transducer 110. If no processing is performed at the interdigital transducer 110, the transverse wave mode cannot be suppressed. The transverse wave mode has a similar propagation mode as the main mode, propagates in the length direction of the finger strip and forms a standing wave at the same time, and multiple transverse wave modes are formed in the entire passband frequency range. The transverse wave mode will affect the flatness of the resonator admittance curve. As shown in Figure 2 Some sharp spurious peaks are generated in the real part and amplitude of the resonator admittance curve. If a filter is formed by the above resonator, the spurious peaks generated by the resonator will appear in the transition band and passband of the filter, forming many burrs, which will deteriorate the performance of the filter.

[0053] At present, there are many methods to suppress the transverse mode, which can be mainly divided into the following four categories:

[0054] The first type is to tilt the interdigital transducer. Specifically, the vertical interdigital transducer is tilted by a certain angle along the X-axis, generally about 3° to 10°. At this time, the finger strip of the interdigital transducer is still perpendicular to the X-axis. This method has good suppression effect on the transverse mode and has a wide range of applications, but it will also bring some spurious waves and affect the performance of the passband.

[0055] The second type is to perform apodization weighting or finger extraction weighting on the opposite regions of the finger strips of the interdigital transducer, to change the length of the opposite regions of the finger strips to suppress the excitation and generation of the transverse mode. This method is simple and easy to implement, but it reduces the quality factor and electrode coupling coefficient of the resonator, and also increases the size of the device.

[0056] The third type is to perform certain processing on the size or shape of the end of the finger strip of the interdigital transducer, by adding an extra metal block or increasing the metal ratio at the end of the finger strip, the propagation of the transverse mode can be suppressed to a certain extent, but this will increase the process cost and manufacturing difficulty. Moreover, if the metal block is large, the gap between the finger strips will be too small, and when applied to a frequency band with a higher frequency, the process requirement is higher, and if the processing precision is not enough, the finger strips may even be short-circuited.

[0057] The fourth type is to perform certain processing on the piezoelectric substrate below the interdigital transducer, such as using a slotting method to physically block the propagation path of the surface acoustic wave, which can also effectively suppress the propagation of the transverse mode, but this method requires high processing precision. It can be seen that the above methods can suppress the propagation of the transverse mode, but cannot guarantee the performance of the resonator.

[0058] Therefore, the present application provides a resonator, which can effectively suppress the transverse mode and improve the Q value of the resonator, thereby improving the performance of the surface acoustic wave filter, by providing a bar structure on the interdigital transducer.

[0059] The structure of the resonator provided by the present application will be described below in conjunction with the accompanying drawings.

[0060] As shown in Figure 3 The resonator 100 provided by the present application includes an interdigital transducer 110 and a bar structure 120. The interdigital transducer 110 includes a first bus bar 111, a second bus bar 112, a plurality of first finger strips 113 and a plurality of second finger strips 114, and the bar structure 120 is arranged at a target region of the interdigital transducer 110. The bar structure 120 includes a plurality of first bars 121 and a plurality of second bars 122.

[0061] It should be understood that the interdigital transducer is also called a coupling electrode or a cross-interaction electrode, and the function of the interdigital transducer is to realize energy transmission and coupling. The interdigital transducer is usually composed of two groups of intersecting metal electrodes (i.e. the plurality of first finger strips 113 and the plurality of second finger strips 114 in the present application), which can convert an electric field into a surface acoustic wave (SAW), or vice versa, to convert the excited surface acoustic wave into an electric field. In the resonator, the interdigital transducer is usually used to convert an electrical signal into a sound wave signal and propagate it, or convert a received sound wave signal into an electrical signal for detection, which is an important part of signal input and output.

[0062] Specifically, as shown in Figure 3 the same end of the plurality of first fingers 113 is connected to the side of the first bus bar 111 close to the second bus bar 112, the same end of the plurality of second fingers 114 is connected to the side of the second bus bar 112 close to the first bus bar 111, and the plurality of first fingers 113 and the plurality of second fingers 114 are arranged in a first direction. Wherein, the first direction can be the length direction of the first bus bar 111, so that Figure 3 for example, the length direction of the first bus bar 111 is the horizontal direction. That is, the plurality of first fingers 113 and the plurality of second fingers 114 are located in the interval between the first bus bar 111 and the second bus bar 112, the plurality of first fingers 113 are connected to the first bus bar 111, the plurality of second fingers 114 are connected to the second bus bar 112, and the first finger 113 is located in the interval between the two adjacent second fingers 114 (or the second finger 114 is located in the interval between the two adjacent first fingers 113).

[0063] As shown in Figure 3 , the plurality of first horizontal bars 121 and the plurality of second horizontal bars 122 are arranged in a cross manner, the adjacent first horizontal bar 121 and the second horizontal bar 122 are distributed in a staggered manner, and the first end of the first horizontal bar 121 in the first direction and the third end of the second horizontal bar 122 in the first direction are connected. Wherein, as shown in Figure 3 , the first direction is the horizontal direction, the left end of the first horizontal bar 121 in the first direction is the second end, which is also the leading end of the first horizontal bar 121, the right end of the first horizontal bar 121 in the first direction is the first end, which is also the trailing end of the first horizontal bar 121, the left end of the second horizontal bar 122 in the first direction is the third end, which is also the leading end of the second horizontal bar 122, and the right end of the second horizontal bar 122 in the first direction is the fourth end, which is also the trailing end of the second horizontal bar 122.

[0064] Specifically, as shown in Figure 4 , the interdigital transducer 110 includes an effective aperture region, a gap region and a target region, the effective aperture region is a region where the first finger 113 and the second finger 114 overlap, that is Figure 4 the region A where the interdigital transducer 110 is located between the dashed line 3 and the dashed line 4 in the figure, and the gap region and the target region are located in the non-overlapping region of the first finger 113 and the second finger 114. In the vertical direction of the first direction, the center line o of the interdigital transducer 110 between the inner side of the first bus bar 111 and the inner side of the second bus bar 112 is sequentially divided into the effective aperture region, the gap region and the target region, that is Figure 4 the region B1 where the interdigital transducer 110 is located between the dashed line 2 and the dashed line 3 in the figure, and Figure 4The area B2 between the dash-dotted line 4 and the dashed line 5, where the interdigital transducer 110 is located, is the target area. Figure 4 The area C1 between the dash-dotted line 1 and the dashed line 2, where the interdigital transducer 110 is located, is the target area. Figure 4 The area C2 between the dash-dotted line 5 and the dashed line 6, where the interdigital transducer 110 is located, is the target area, and if the interdigital transducer 110 includes a dummy finger, the target area is generally the area where the dummy finger is located.

[0065] The first horizontal bar 121 and the second horizontal bar 122 are staggered, that is, the first horizontal bar 121 and the second horizontal bar 122 are not flush on both sides of the length direction of the first finger 113, but are staggered, for example, the first horizontal bar 121 and the second horizontal bar 122 are in a Z-shaped structure. It can also be said that the first distance and the second distance are not the same, wherein the first distance can be the distance between the first bus bar 111 and the first horizontal bar 121 located in the C1 area (i.e., a1 in Figure 4 ), and the second distance can be the distance between the first bus bar 111 and the second horizontal bar 122 located in the C1 area (i.e., b1 in Figure 4 ). Figure 4 Alternatively, the first distance can be the distance between the second bus bar 112 and the first horizontal bar 121 located in the C2 area (i.e., a2 in Figure 4 ), and the second distance can be the distance between the second bus bar 112 and the second horizontal bar 122 located in the C2 area (i.e., b2 in ).

[0066] Specifically, as shown in the admittance curve diagrams of the no-horizontal-bar structure and the horizontal-bar structure in Figure 5a and Figure 5b It can be seen that after the horizontal-bar structure 120 is set, the spurious peak caused by the transverse wave mode is smaller, indicating that the horizontal-bar structure 120 can effectively suppress the transverse wave mode. As shown in the Smith chart diagrams of the no-horizontal-bar structure and the horizontal-bar structure in Figure 6a and Figure 6b It can be seen that after the horizontal-bar structure 120 is set, the Q value of the resonator 100 at the anti-resonance frequency is higher.

[0067] The resonator 100 provided by the present application sets the horizontal-bar structure 120 in the dummy finger area of the interdigital transducer 110. The horizontal-bar structure 120 can form waveguides of different sizes with the adjacent finger of the interdigital transducer, change the distribution of the electric field at the end of the finger, make the electric field distribution between the two adjacent fingers have a mutation, and play a role in suppressing the propagation of the transverse wave mode. Moreover, the horizontal-bar structure 120 can reflect the transversely propagating acoustic wave, limit more energy between the interdigital transducers 110 for propagation, reduce the energy escaping, and significantly improve the Q value of the resonator, thereby improving the performance of the resonator.

[0068] It should be understood that the Q value of the resonator is an important parameter for measuring the performance of the resonator, which describes the degree of energy loss and frequency selectivity of the resonator. The higher the Q value, the smaller the energy loss of the resonator and the better the frequency selectivity. The resonator with high Q value has a narrow bandwidth, can produce a higher response near a specific frequency, and can maintain oscillation for a longer time.

[0069] For example, the materials of the first horizontal bar 121 and the second horizontal bar 122 are metal materials, combinations of metal materials, or metal oxides, i.e., the horizontal bar structure 120 is composed of metal materials, combinations of metal materials, or metal oxides. The material of the interdigital transducer 110 can be a conductive material such as a metal material, a combination of metal materials, or a metal oxide, and the material of the interdigital transducer 110 and the material of the horizontal bar structure 120 can be the same or different.

[0070] For example, the first bus bar 111, the second bus bar 112, the plurality of first finger bars 113, and the plurality of second finger bars 114 constituting the interdigital transducer 110 can be an integrated structure. That is, the first bus bar 111, the second bus bar 112, the plurality of first finger bars 113, and the plurality of second finger bars 114 are manufactured on the same substrate at the same time through a one-time processing process, which has the advantages of compact space, high mechanical stability, excellent electrical performance, and low production cost.

[0071] Further, as shown in FIG. 1, the resonator 100 further includes an effective reflector 130 disposed on both sides of the interdigital transducer 110. Figure 3

[0072] It should be understood that the effective reflector is also called a mirror or an attenuator, and the function of the effective reflector is to control the propagation and interference of acoustic waves in the resonator. The effective reflector is usually composed of periodic metal stripes or electrodes, which are used to reflect, attenuate, or control the propagation direction and energy of acoustic waves. The design and process of the effective reflector can adjust parameters such as reflection coefficient, frequency selectivity, and power loss to achieve control and optimization of acoustic waves in the resonator. The effective reflector can be used to increase the quality factor of the resonator, limit the propagation range of acoustic waves, reduce reflection loss, etc. The interaction between the effective reflector and the interdigital transducer plays an important role in the performance and function of the resonator.

[0073] Specifically, the resonator described above can be applied to structures including resonators such as a Coupled Resonator Filter (CRF) structure, a ladder weighting, etc.

[0074] In some optional embodiments, the length of the gap region in the direction perpendicular to the first direction (i.e., the length of the gap region in the direction of the second direction) is greater than the length of the gap region in the first direction. Figure 4 ​The value range of d1 in the d1) is the width of the target horizontal bar to 0.5λ, that is, the width of the target horizontal bar≤d1≤0.5λ, for example, d1 can be the width of the target horizontal bar, 0.3λ or 0.5λ, etc. Wherein, λ is the wavelength of the surface acoustic wave, the target horizontal bar is the first horizontal bar or the second horizontal bar, the width of the target horizontal bar is less than or equal to 0.7um, or the width of the target horizontal bar is greater than or equal to 0.28um, that is, the width of the target horizontal bar≤0.7um, for example, the width of the target horizontal bar can be 0.7um, 0.5um, 0.3um or 0.2um, etc., or the width of the target horizontal bar≥0.28um, for example, the width of the target horizontal bar can be 0.28um, 0.3um, 0.5um or 0.8um, etc. In addition, the length of the area between the target bus bar inner side and the effective aperture area in the direction perpendicular to the first direction (i.e. Figure 4 The value range of d2 and d3 in the d2 and d3) is 1λ to 2λ, that is, 1λ≤d2≤2λ, 1λ≤d3≤2λ, for example, d2 and d3 can be 1λ, 1.5λ, 1.8λ or 2λ, etc. Wherein, the target bus bar includes the first bus bar and / or the second bus bar.

[0075] It should be noted that, Figure 3 The setting mode of the horizontal bar structure 120 shown in the above is only an example, and the setting mode of the horizontal bar structure 120 will be further described below in combination with the drawings.

[0076] Specifically, the length direction of the first horizontal bar 121 and the length direction of the second horizontal bar 121 are not limited by the present application.

[0077] For example, as shown in the figure, Figure 3 The length direction of the first horizontal bar 121 and the length direction of the second horizontal bar 122 can be perpendicular to each other.

[0078] In other embodiments, the length direction of the first horizontal bar 121 and the length direction of the second horizontal bar 122 can also be not perpendicular to each other.

[0079] When the first end of the first horizontal bar 121 in the first direction (the first end) and the one end of the second horizontal bar 122 in the first direction (the third end) are connected, the present application does not limit the position of the other end of the first horizontal bar 121 in the first direction (i.e. the second end) and the other end of the second horizontal bar in the first direction (i.e. the fourth end).

[0080] For example, the second end of the first horizontal bar 121 in the first direction and / or the fourth end of the second horizontal bar 122 in the first direction are in contact with the target finger bar; and / or, the second end of the first horizontal bar in the first direction is connected with the fifth end of the third horizontal bar in the first direction, wherein the third horizontal bar is another second horizontal bar adjacent to the first horizontal bar among the plurality of second horizontal bars.

[0081] For example, as shown in Figure 3 and Figure 7 , from left to right, the second end of the first first horizontal bar 121 in the C1 region is in contact with the first finger bar 113, the first end of the first first horizontal bar 121 is in contact with the third end of the first second horizontal bar 122, the second end of the second first horizontal bar 121 is connected to the fourth end of the first second horizontal bar 122 (i.e. the fifth end of the third horizontal bar), and the fourth end of the last second horizontal bar 122 in the C2 region is in contact with the second finger bar 114.

[0082] For another example, as shown in Figure 8 and Figure 9 , the second end of the first first horizontal bar 121 in the C1 region is in contact with the first finger bar 113, and the second end of the second first horizontal bar 121 can not only be connected to the fourth end of the first second horizontal bar 122 (i.e. the fifth end of the third horizontal bar), but also be in contact with one side of the first finger bar 113.

[0083] In some other optional embodiments, there is a gap between the second end of the second horizontal bar in the first direction and the fifth end of the third horizontal bar in the first direction. For example, as shown in Figure 10 , the second end of the second first horizontal bar 121 in the C1 region is located on the first finger bar 113, and the fourth end of the first second horizontal bar 122 (i.e. the fifth end of the third horizontal bar) is in contact with the edge of the first finger bar 113, i.e. the second end of the second first horizontal bar 121 in the C1 region and the fourth end of the first second horizontal bar 122 can not be in contact, and there is a certain gap between them.

[0084] Further, as shown in Figure 3 and Figure 7 , the first horizontal bar 121 and the second horizontal bar 122 have a rectangular structure, and adjacent first horizontal bars 121 and second horizontal bars 122 have a Z-shaped structure distribution. The present application does not limit the setting position of the first horizontal bar 121 and the second horizontal bar 122 in the length direction of the first finger bar 113, as long as they are distributed staggered.

[0085] For example, as shown in Figure 3 , the plurality of first horizontal bars 121 close to the first bus bar 111 are arranged close to the effective aperture region, the plurality of second horizontal bars 122 close to the first bus bar 111 are arranged away from the effective aperture region, the plurality of first horizontal bars 121 close to the second bus bar 112 are arranged away from the effective aperture region, and the plurality of second horizontal bars 122 close to the second bus bar 112 are arranged close to the effective aperture region. For another example, as shown in Figure 7As shown, the plurality of first horizontal bars 121 close to the first bus bar 111 can also be arranged away from the effective aperture region, the plurality of second horizontal bars 122 close to the first bus bar 111 can also be arranged close to the effective aperture region, the plurality of first horizontal bars 121 close to the second bus bar 112 can also be arranged close to the effective aperture region, and the plurality of second horizontal bars 122 close to the second bus bar 112 can also be arranged away from the effective aperture region.

[0086] In the present application, the length of the first horizontal bar 121, the length of the second horizontal bar 122, and the position where the one end of the first horizontal bar 121 in the first direction and the one end of the second horizontal bar 122 in the first direction are connected are not limited, and the connection of the first horizontal bar 121 and the second horizontal bar 122 in the first direction can be within the gap between two adjacent first finger bars 113 and / or within the gap between two adjacent second finger bars 114, the connection of the first horizontal bar 121 and the second horizontal bar 122 in the first direction can also be on the target finger bar (i.e. the first finger bar 113 or the second finger bar 114), and the connection of the first horizontal bar 121 and the second horizontal bar 122 in the first direction can also be located at the edge of the target finger bar in the first direction.

[0087] As shown in the examples of Figure 3 , Figure 7 , Figure 8 and Figure 9 , the plurality of first horizontal bars 121 and the plurality of second horizontal bars 122 are arranged in sequence, the length of the first horizontal bar 121 and the length of the second horizontal bar 122 are greater than the width of the target finger bar, at least part of the first horizontal bar 121 and at least part of the second horizontal bar 122 are arranged within the gap between the target finger bars, and at least part of the first horizontal bar and at least part of the second horizontal bar are arranged on the target finger bar.

[0088] That is, the plurality of first horizontal bars 121 and the plurality of second horizontal bars 122 are not all arranged on the target finger bar. For example, as shown in Figure 7 , from left to right, the last first horizontal bar 121 in the C1 region is arranged within the gap, and the other first horizontal bars 121 are arranged on the first finger bar 113 (wherein part of the first horizontal bar 121 is arranged on the first finger bar 113 and part is arranged within the gap of the first finger bar 113), and the plurality of second horizontal bars 122 in the C1 region are all arranged within the gap between the first finger bars 113. The first horizontal bars 121 in the C2 region are all arranged within the gap between the second finger bars 114, and the second horizontal bars 122 in the C2 region are arranged on the second finger bar 114 (wherein part of the second horizontal bar 122 is arranged on the second finger bar 114 and part is arranged within the gap of the second finger bar 114).

[0089] As shown in Figure 8 and Figure 9As shown, the adjacent first horizontal bars 121 and the second horizontal bars 122 are distributed in a Z-shaped structure, the length of the first horizontal bar 121 and the length of the second horizontal bar 122 are both greater than or equal to the width of the target finger bar, the first horizontal bar 121 is in direct contact with the second horizontal bar 122 at the first end in the first direction at the third end in the first direction, the first horizontal bar 121 is in contact with one side of the first finger bar 113 and / or one side of the second finger bar 114 at the second end in the first direction, and the second horizontal bar 122 is in contact with one side of the first finger bar 113 and / or one side of the second finger bar 114 at the fourth end in the first direction.

[0090] Specifically, among the plurality of second horizontal bars 122 near the first bus bar 111, the length of the second horizontal bar 122 at the tail end of the first bus bar 111 is equal to the width of the target finger, and the widths of the other second horizontal bars 122 near the first bus bar 111 are greater than the width of the target finger, wherein the left end of the first bus bar 111 is the leading end, and the right end of the first bus bar 111 is the trailing end. Among the plurality of first horizontal bars 121 near the second bus bar 112, the length of the first horizontal bar 121 at the leading end of the second bus bar 112 is equal to the width of the target finger, and the widths of the other first horizontal bars 121 near the second bus bar 112 are greater than the width of the target finger, wherein the left end of the second bus bar 112 is the leading end, and the right end of the second bus bar 112 is the trailing end.

[0091] For example, Figure 9 As shown, the length of the first horizontal bar 121 in region C1 (the first, third, fifth, seventh, and ninth horizontal bars from left to right in region C1) is greater than the width of the target finger bar. The length of the tenth horizontal bar from left to right in region C1 (i.e., the second horizontal bar 122 located at the tail end of first bus bar 111 among the multiple second horizontal bars 122 near first bus bar 111) is equal to the width of the target finger bar, so that the tail end of the horizontal bar structure is flush with the tail end of first bus bar 111. The tail end of horizontal bar structure 120 is the last horizontal bar in the first direction, which may be first horizontal bar 121 or second horizontal bar 122.

[0092] For example, Figure 11 As shown, at least one first bar 121 is partially disposed on the target finger and another portion is disposed in the gap between the target fingers; at least one second bar 122 is partially disposed on the target finger and another portion is disposed in the gap between the target fingers.

[0093] For example, Figure 12 and Figure 13As shown, the plurality of first horizontal strips 121 and the plurality of second horizontal strips 122 are arranged in sequence, the length of the first horizontal strip 121 and the length of the second horizontal strip 122 are less than or equal to the width of the target finger strip, and at least part of the first horizontal strips or at least part of the second horizontal strips are all arranged in the gap between the target finger strips.

[0094] For example, as shown in Figure 12 , all the second horizontal strips 122 in the C1 region are arranged in the gap between the first finger strips 113, part of the first horizontal strips 121 in the C1 region are arranged in the gap between the first finger strips 113, and the other part of the first horizontal strips 121 are arranged on the first finger strips 113; all the second horizontal strips 122 in the C2 region are arranged in the gap between the second finger strips 114, part of the first horizontal strips 121 in the C2 region are arranged in the gap between the second finger strips 114, and the other part of the first horizontal strips 121 are arranged on the second finger strips 114.

[0095] For example, part of the at least one first horizontal strip is arranged on the target finger strip, and part of the at least one first horizontal strip is arranged in the gap between the target finger strips; part of the at least one second horizontal strip is arranged on the target finger strip, and part of the at least one second horizontal strip is arranged in the gap between the target finger strips.

[0096] Specifically, as shown in Figure 11 , Figure 12 and Figure 13 , the adjacent first horizontal strips 121 and the second horizontal strips 122 are arranged in a Z-shaped structure, the length of the first horizontal strip 121 and the length of the second horizontal strip 122 are the width of the target finger strip, the interval L1 between the same side of the adjacent two first finger strips 113, the interval L2 between the same side of the adjacent two second finger strips 114, or the interval L3 between the two sides of the adjacent first finger strip 113 and the second finger strip 114 away from each other, and the target finger strip is the first finger strip 113 or the second finger strip 114.

[0097] Among them, as shown in Figure 12 and Figure 13 , the length of the first horizontal strip 121 and the length of the second horizontal strip 122 are both the width of the target finger strip. As shown in Figure 11As shown, the length of the first horizontal bar 121 located at the tail end of the first bus bar 111 is equal to the interval L3 between the two sides of the adjacent first finger bar 113 and second finger bar 114 away from each other, the width of the other first horizontal bar 121 close to the first bus bar 111 is the interval L1 between the same side of the adjacent two first finger bars 113, the length of the first horizontal bar 121 located at the head end of the second bus bar 112 is equal to the interval L3 between the two sides of the adjacent first finger bar 113 and second finger bar 114 away from each other, the width of the other first horizontal bar 121 close to the second bus bar 112 is the interval L2 between the same side of the adjacent two second finger bars 114, and the length of the second horizontal bar 122 is the interval L2 between the same side of the adjacent two second finger bars 114.

[0098] The present application does not limit the implementation mode of the first end of the first horizontal bar 121 in the first direction and the first end of the second horizontal bar 122 in the first direction, for example, as shown in Figure 3 、 Figures 7 to 13 The first end of the first horizontal bar 121 in the first direction and the third end of the second horizontal bar 122 in the first direction can be directly connected.

[0099] For another example, the horizontal bar structure 120 further comprises a plurality of bar-shaped structures 123, at this time, the first end of the first horizontal bar 121 in the first direction and the third end of the second horizontal bar 122 in the first direction can be connected through the bar-shaped structure.

[0100] For example, as shown in Figure 14 and Figure 15 The adjacent first horizontal bar 121 and second horizontal bar 122 are distributed in a Z-shaped structure, the length of the first horizontal bar 121 and the length of the second horizontal bar 122 are both greater than the width of the target finger bar, and the two ends of the bar-shaped structure 123 in the length direction of the first finger bar 113 are respectively in contact with the first end of the first horizontal bar 121 in the first direction and the third end of the second horizontal bar 122 in the first direction, that is, the indirect contact between the one end (i.e. the first end) of the first horizontal bar 121 in the first direction and the one end (i.e. the third end) of the second horizontal bar 122 in the first direction.

[0101] Specifically, the direction perpendicular to the first direction is the length direction of the bar-shaped structure 123, and in the direction perpendicular to the first direction, the two ends of the bar-shaped structure are respectively connected with the end of the first horizontal bar 121 and the end of the second horizontal bar 122, so that the first horizontal bar 121, the bar-shaped structure 123 and the second horizontal bar 122 are sequentially connected to form a Z-shaped structure.

[0102] Wherein, the plurality of first horizontal bars 121 close to the first bus bar 111 are respectively located on the plurality of first finger bars 113, the plurality of second horizontal bars 122 close to the first bus bar 111 are respectively located in the intervals between the plurality of first finger bars 113, the plurality of bar structures 123 close to the first bus bar 111 are located in the intervals between the plurality of first finger bars 113, the plurality of second horizontal bars 122 close to the second bus bar 112 are respectively located on the plurality of second finger bars 114, the plurality of first horizontal bars 121 close to the second bus bar 112 are respectively located in the intervals between the plurality of second finger bars 114, the plurality of bar structures 123 close to the second bus bar 112 are located in the intervals between the plurality of second finger bars 114, and the target finger bar is the first finger bar or the second finger bar.

[0103] Further, in order to improve the performance of the interdigital transducer, in some optional embodiments, as shown in FIG. 1C, the interdigital transducer 110 further comprises a plurality of third finger bars 115 and a plurality of fourth finger bars 116. The same end of the plurality of third finger bars 115 is connected to the side of the first bus bar 111 close to the second bus bar 112, and the plurality of third finger bars 115 and the plurality of second finger bars 114 are oppositely arranged. The same end of the plurality of fourth finger bars 116 is connected to the side of the second bus bar 112 close to the first bus bar 111, and the plurality of fourth finger bars 116 and the plurality of first finger bars 113 are oppositely arranged. Wherein, the length of the third finger bar 115 is less than the length of the first finger bar 113, and the length of the fourth finger bar 116 is less than the length of the second finger bar 114. Figure 16

[0104] Specifically, the first finger bar 113 and the second finger bar 114 can be true finger, and the third finger bar 115 and the fourth finger bar 116 can be false finger. The interdigital transducer 110 without false finger, the true finger forms a capacitance structure between the true finger, when the external mechanical quantity acts on the true finger, the displacement of the true finger is caused, thereby changing the capacitance value between the true finger, and further generating an electrical signal. The structure of the interdigital transducer 110 without false finger is simpler, and the manufacturing cost is lower. The interdigital transducer 110 including false finger, the false finger and the true finger together form a capacitance sensor structure, when the external mechanical quantity acts on the true finger, the displacement of the true finger is caused, thereby changing the capacitance value between the true finger and the false finger, and further generating an electrical signal. The interdigital transducer 110 including false finger can increase the sensitivity and linearity, and reduce the common mode interference to the mechanical quantity.

[0105] When the interdigital transducer 110 provided with the horizontal bar structure 120 further includes false finger (i.e. the third finger bar 115 and the fourth finger bar 116), the target finger bar in the above description also includes the third finger bar 115 and the fourth finger bar 116. That is, the present embodiment can be formed by arranging the third finger bar 115 and the fourth finger bar 116 in any of the above embodiments.

[0106] ​Also, after the third finger 115 and the fourth finger 116 are set, the present application still does not limit the staggered distribution of the adjacent first horizontal bar 121 and the second horizontal bar 122, the length of the first horizontal bar 121, the length of the second horizontal bar 122, the implementation mode of the connection between the end of the first horizontal bar 121 in the first direction and the end of the second horizontal bar 122 in the first direction, and the length direction of the first horizontal bar 121 and the length direction of the second horizontal bar 121.

[0107] For example, as shown in Figure 16 and Figure 17 , the adjacent first horizontal bar 121 and the second horizontal bar 122 are staggered, the length of the first horizontal bar 121 and the length of the second horizontal bar 122 are both greater than the width of the target finger, and the end of the first horizontal bar 121 in the first direction directly contacts the end of the second horizontal bar 122 in the first direction to achieve connection.

[0108] Among them, the multiple first horizontal bars 121 close to the first bus bar 111 are respectively arranged on the multiple first fingers 113, the multiple second horizontal bars 122 close to the first bus bar 111 are respectively arranged on the multiple third fingers 115, the multiple first horizontal bars 121 close to the second bus bar 112 are respectively arranged on the multiple fourth fingers 116, and the multiple second horizontal bars 122 close to the second bus bar 112 are respectively arranged on the multiple second fingers 114.

[0109] Specifically, in the case where the adjacent first horizontal bar 121 and the second horizontal bar 122 are distributed in a Z-shaped structure, the distance between the side of the first target horizontal bar close to the second bus bar 112 and the end of the corresponding third finger 115 away from the first bus bar 111 is greater than or equal to 0. The distance between the side of the second target horizontal bar close to the first bus bar 111 and the end of the corresponding fourth finger 116 away from the second bus bar 112 is greater than or equal to 0. Among them, the first target horizontal bar is the second horizontal bar 122 close to the first bus bar 111 among the multiple second horizontal bars 122, and the second target horizontal bar is the first horizontal bar 121 close to the second bus bar 112 among the multiple first horizontal bars 121.

[0110] For example, as shown in Figure 16 , the side of the second horizontal bar 122 close to the second bus bar 112 in the C1 region and the end of the third finger 115 where the second horizontal bar 122 is located away from the first bus bar 111 do not coincide (i.e. the distance is greater than 0), and the side of the first horizontal bar 121 close to the first bus bar 111 in the C2 region and the end of the fourth finger 116 where the first horizontal bar 121 is located away from the second bus bar 112 do not coincide (i.e. the distance is greater than 0).

[0111] For another example, as shown in Figure 17As shown, in region C1, the side of the second horizontal bar 122 close to the second bus bar 112 overlaps with the end of the third finger 115 where the second horizontal bar 122 is located, away from the first bus bar 111 (i.e., the spacing is 0). The side of the first horizontal bar 121 in region C2 close to the first bus bar 111 overlaps with the end of the fourth finger 116 where the first horizontal bar 121 is located, away from the second bus bar 112 (i.e., the spacing is greater than 0).

[0112] For example, Figure 18 and Figure 19 As shown, the horizontal bar structure 120 also includes a plurality of strip structures 123, and the adjacent first horizontal bars 121 and the second horizontal bars 122 are distributed in a Z-shaped structure. The length of the first horizontal bar 121 and the length of the second horizontal bar 122 are both greater than the width of the target finger bar, and the two ends of the strip structure 123 in the length direction of the first finger bar 113 are respectively in contact with one end of the first horizontal bar 121 in the first direction (i.e., the first end) and one end of the second horizontal bar 122 in the first direction (i.e., the third end) to achieve connection.

[0113] Among them, the multiple first horizontal bars 121 close to the first bus bar 111 are respectively arranged on the multiple first fingers 113, the multiple second horizontal bars 122 close to the first bus bar 111 are respectively arranged on the multiple third fingers 115, and the multiple strip structures 123 close to the first bus bar 111 are located in the gaps between the adjacent first fingers 113 and third fingers 115. The multiple first horizontal bars 121 close to the second bus bar 112 are respectively arranged on the multiple fourth fingers 116, and the multiple second horizontal bars 122 close to the second bus bar 112 are respectively arranged on the multiple second fingers 114, and the multiple strip structures 123 close to the second bus bar 112 are located in the gaps between the adjacent second fingers 114 and fourth fingers 116.

[0114] For example, Figure 20 and Figure 21 As shown, the length of the first horizontal bar 121 and the length of the second horizontal bar 122 are both greater than or equal to the width of the target finger, the first horizontal bar 121 is in direct contact with the second horizontal bar 122 at one end in the first direction, the first horizontal bar 121 is in direct contact with one side of the first finger 113, one side of the second finger 114 or one side of the fourth finger 116 at the other end in the first direction (i.e., the second end), and the second horizontal bar 122 is in direct contact with one side of the first finger 113, one side of the second finger 114 or one side of the third finger 115 at the other end in the first direction (i.e., the fourth end). The target finger is the first finger 113, the second finger 114, the third finger 115 or the fourth finger 116.

[0115] For example, Figure 22As shown, the first transverse bar 121 at one end of the first direction and the second transverse bar 122 at one end of the first direction are in contact, and the length of the first transverse bar 121 and the length of the second transverse bar 122 are the interval L1 between the same side of the two adjacent first finger bars 113, the interval L2 between the same side of the two adjacent second finger bars 114, the interval L3 between the two sides of the first finger bar 113 and the third finger bar 115 away from each other, or the interval L4 between the two sides of the second finger bar 114 and the fourth finger bar 116 away from each other. The target finger bar is the first finger bar 113, the second finger bar 114, the third finger bar 115 or the fourth finger bar 116.

[0116] For example, the first ratio (i.e. the metal duty ratio) between the width of the first finger bar 113 and the first width is in the range of 0.35 to 0.75. That is, the first ratio can be any value in the range of 0.35 to 0.75, for example, the first ratio can be 0.35, 0.45, 0.5, 0.6 or 0.75, etc. Wherein the first width is the sum of the interval between the two sides of the first finger bar 113 and the second finger bar 114 close to each other and the width of the first finger bar 113.

[0117] Specifically, as shown in the figure, Figure 23 The first ratio η = a / p, where a represents the width of the first finger bar 113, and p represents the first width, the first width p = a + b, and b represents the interval between the two sides of the first finger bar 113 and the second finger bar 114 close to each other.

[0118] It should be understood that the metal duty ratio has an important influence on the performance and function of the interdigital transducer. Specifically, more finger bars can provide better energy coupling and transmission path, so the increase of the metal duty ratio can improve the transmission efficiency of the interdigital transducer, however, to a certain extent, too high metal duty ratio may cause energy dissipation and scattering, resulting in reduced transmission efficiency. The change of the metal duty ratio will affect the frequency response of the interdigital transducer, and the resonant frequency or the frequency bandwidth of the interdigital transducer can be adjusted according to the different metal duty ratios. The metal duty ratio is also related to the mechanical strength and stability of the interdigital transducer, and a suitable metal duty ratio can provide sufficient structural strength to ensure the stability and reliability of the interdigital transducer under working conditions.

[0119] In this embodiment, the metal duty ratio is limited to between 0.35 and 0.75, which can better balance the transmission efficiency, frequency response, mechanical strength and stability of the interdigital transducer, and further improve the performance of the resonator.

[0120] The present application also provides a surface acoustic wave filter, as shown in the figure, Figure 24 The surface acoustic wave filter comprises the resonator 100 of any of the preceding embodiments, a piezoelectric material layer 200 and a substrate 300.

[0121] Specifically, the piezoelectric material layer 200 covers the upper surface of the substrate 300, and the at least one resonator 100 is located on the upper surface of the piezoelectric material layer 200, for converting an input electrical signal into an acoustic surface wave signal.

[0122] In the embodiment, the resonator provided by the above-mentioned embodiment can effectively reduce the insertion loss of the filter, reduce the ripple in the passband, improve the rectangularity of the filter, and further improve the performance of the filter.

[0123] Optionally, the thickness of the interdigital transducer in the resonator 100 is in a range of 0.05λ to 0.15λ, where λ is the wavelength of the acoustic surface wave. Specifically, the thickness of the interdigital transducer can be any value between 0.05λ and 0.15λ, for example, the thickness of the interdigital transducer can be 0.05λ, 0.06λ, 0.08λ, 0.1λ or 0.15λ.

[0124] In the embodiment, the thickness of the interdigital transducer is limited to be between 0.05λ and 0.15λ, which can balance the sensitivity, frequency response and dynamic response speed of the interdigital transducer, optimize the performance of the resonator, and further improve the performance of the acoustic surface wave filter.

[0125] It should be understood that the sensitivity of the interdigital transducer refers to the change rate of the output signal relative to the input mechanical quantity.

[0126] For example, the piezoelectric material of the piezoelectric material layer can be 30° to 60° rotated Y-cut X-propagation lithium tantalate or lithium niobate, and the thickness of the piezoelectric material layer is in a range of 0.1λ to 0.5λ, where λ is the wavelength of the acoustic surface wave. Specifically, the thickness of the piezoelectric material layer can be any value between 0.1λ and 0.5λ, for example, the thickness of the piezoelectric material layer can be 0.1λ, 0.2λ, 0.3λ, 0.4λ or 0.5λ.

[0127] In the embodiment, the thickness of the piezoelectric material layer is limited to be between 0.1λ and 0.5λ, which can ensure the structural stability of the acoustic surface wave filter.

[0128] For example, the substrate 300 includes a first substrate layer 310 and a second substrate layer 320. The material of the first substrate layer 310 can be a low acoustic velocity material such as silicon dioxide (SiO2), and the thickness of the first substrate layer 310 is in a range of 0.1λ to 0.5λ. The material of the second substrate layer 320 can be a high acoustic velocity material such as high-resistance silicon, silicon carbide, sapphire, quartz or magnesia-alumina spinel.

[0129] Specifically, λ is the wavelength of the surface acoustic wave, the thickness of the first substrate layer 310 can be any value between 0.1λ and 0.5λ, for example, the thickness of the piezoelectric material layer can be 0.1λ, 0.2λ, 0.3λ, 0.4λ or 0.5λ.

[0130] For example, the surface acoustic wave filter can be a Phase-Only Interrogation (POI) structure or a Temperature Compensated SAW (TCSAW) with a thick film cover layer.

[0131] In the description of the present application, the description of the terms "the embodiment", "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the description of the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction.

[0132] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0133] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0134] In this application, unless otherwise clearly indicated and limited, the terms "mounting", "connection", "connecting", "fixing" and the like should be interpreted broadly, for example, can be fixed connection, can also be detachable connection, or integrated; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise clearly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0135] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and simple improvement made on the essential content of the present application shall be included in the protection scope of the present application.

Claims

1. A resonator, characterized by, The resonator comprises an interdigital transducer and a transverse bar structure. The interdigital transducer comprises a first bus bar, a second bus bar, a plurality of first fingers and a plurality of second fingers. The first bus bar and the second bus bar are oppositely arranged. The same end of the plurality of first fingers is connected to the side of the first bus bar close to the second bus bar, and the same end of the plurality of second fingers is connected to the side of the second bus bar close to the first bus bar. The plurality of first fingers and the plurality of second fingers are arranged in a first direction, which is the length direction of the first bus bar. The transverse bar structure is arranged in a target region of the interdigital transducer. The transverse bar structure comprises a plurality of first transverse bars and a plurality of second transverse bars. The plurality of first transverse bars and the plurality of second transverse bars are arranged in a cross manner. Adjacent first transverse bars and second transverse bars are distributed in a staggered manner. The first end of the first transverse bar in the first direction is connected to the third end of the second transverse bar in the first direction. In a direction perpendicular to the first direction, between the inner side of the first bus bar and the inner side of the second bus bar, the center line of the interdigital transducer is sequentially divided into an effective aperture region, a gap region and the target region.

2. The resonator of claim 1, wherein The effective aperture region is the overlapping region of the plurality of first fingers and the plurality of second fingers. The length of the gap region in the direction perpendicular to the first direction is in the range of the width of the target transverse bar to 0.5λ. The length of the region between the target bus bar inner side and the effective aperture region in the direction perpendicular to the first direction is in the range of 1λ to 2λ. The width of the target transverse bar is less than or equal to 0.7um, or the width of the target transverse bar is greater than or equal to 0.28um. λ is the wavelength of the surface acoustic wave. The target transverse bar is the first transverse bar or the second transverse bar. The target bus bar comprises the first bus bar and / or the second bus bar.

3. The resonator of claim 1, wherein The length direction of the first transverse bar and the length direction of the second transverse bar are both perpendicular to the length direction of the first finger.

4. The resonator of claim 1, wherein The first transverse bar and the second transverse bar are both in a rectangular structure. Adjacent first transverse bars and second transverse bars in the transverse bar structure are in a Z-shaped structure.

5. The resonator of claim 1, wherein The second end of the first transverse bar in the first direction and / or the fourth end of the second transverse bar in the first direction are in contact with a target finger. The target finger comprises the first finger or the second finger. And / or The second end of the first transverse bar in the first direction is connected to the fifth end of a third transverse bar in the first direction. The third transverse bar is another second transverse bar adjacent to the first transverse bar in the plurality of second transverse bars.

6. The resonator of claim 5, wherein The first horizontal bars and the second horizontal bars are arranged in sequence, the length of the first horizontal bar and the length of the second horizontal bar are greater than the width of the target finger, and at least part of the first horizontal bar and at least part of the second horizontal bar are arranged in the gap between the target fingers, and at least part of the first horizontal bar and at least part of the second horizontal bar are arranged on the target finger. And / or, Part of the at least one first horizontal bar is arranged on the target finger, and part is arranged in the gap between the target fingers, and part of the at least one second horizontal bar is arranged on the target finger, and part is arranged in the gap between the target fingers.

7. The resonator of claim 5, wherein, The first horizontal bars and the second horizontal bars are arranged in sequence, the length of the first horizontal bar and the length of the second horizontal bar are less than or equal to the width of the target finger, and at least part of the first horizontal bar or at least part of the second horizontal bar are arranged on the target finger or in the gap between the target fingers. And / or, Part of the at least one first horizontal bar is arranged on the target finger, and part is arranged in the gap between the target fingers, and part of the at least one second horizontal bar is arranged on the target finger, and part is arranged in the gap between the target fingers.

8. The resonator of claim 5, wherein, The length of the first horizontal bar and the length of the second horizontal bar are the width of the target finger, the distance between the same side of two adjacent first fingers, the distance between the same side of two adjacent second fingers, or the distance between the two sides of the first finger and the second finger away from each other.

9. The resonator of claim 5, wherein, The horizontal bar structure further comprises a plurality of bar-shaped structures, and one end of the first horizontal bar in the first direction is connected to one end of the second horizontal bar in the first direction through the bar-shaped structure.

10. The resonator of any one of claims 5 to 9, wherein, The interdigital transducer further comprises a plurality of third fingers and a plurality of fourth fingers, the same end of the plurality of third fingers is connected to the side of the first bus bar close to the second bus bar, and the plurality of third fingers and the plurality of second fingers are oppositely arranged, the same end of the plurality of fourth fingers is connected to the side of the second bus bar close to the first bus bar, and the plurality of fourth fingers and the plurality of first fingers are oppositely arranged, and the target finger further comprises the third finger or the fourth finger.

11. The resonator of claim 10, wherein, The distance between the first target horizontal bar close to the side of the second bus bar and the end of the corresponding third finger away from the first bus bar is greater than or equal to 0, wherein the first target horizontal bar is the second horizontal bar close to the first bus bar in the plurality of second horizontal bars; and / or, A distance between a side of the second target horizontal bar close to the first bus bar and an end of the corresponding fourth finger bar away from the second bus bar is greater than or equal to 0, wherein the second target horizontal bar is a first horizontal bar close to the second bus bar among the plurality of first horizontal bars.

12. A surface acoustic wave filter, characterized by, Comprising: at least one resonator according to any one of claims 1 to 11, a piezoelectric material layer and a substrate; the piezoelectric material layer is covered on an upper surface of the substrate, and at least one of the resonators is located on an upper surface of the piezoelectric material layer.

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