Resonator, filter and communication equipment

Abstract

The embodiment of the invention provides a resonator, a filter and communication equipment, which are used for solving the problem of large occupied area on the layout of a circuit substrate when the resonator is matched with other devices. The resonator includes a substrate and a resonant layer. The resonance layer is located on one side of the substrate and comprises a first electrode, a second electrode and a piezoelectric layer which are arranged in a stacked mode, and the piezoelectric layer is located between the first electrode and the second electrode. Wherein at least one of the substrate, the first electrode, the second electrode and the piezoelectric layer is a reference layer, the edge of the reference layer comprises a first side surface and a second side surface which are adjacent to each other, and an included angle between the first side surface and the second side surface and located within the reference layer is a reflex angle. According to the resonator provided by the invention, the two side surfaces forming the interior angle of the reflex angle in the reference layer are utilized to form the semi-enclosed area. And the half-surrounded area is utilized to tightly combine the resonator with other devices in the filter on the circuit substrate, so that the layout utilization rate of the circuit substrate is improved.

Description

Technical Field

[0001] The present application relates to the field of electronic devices, and in particular to a resonator, a filter, and a communication device. Background Art

[0002] With the advent of the era of big data and the Internet of Things, filters installed in communication equipment will inevitably develop in the direction of low loss, miniaturization, and integration. Among them, bulk acoustic wave (BAW) resonators based on piezoelectric materials are a commonly used filter solution. Using high-performance BAW resonators and specific circuit structures, high-performance filters can be built.

[0003] However, as filters develop towards low loss, miniaturization, and integration, filters place higher demands on resonators in terms of flexibility, etc. However, in the related art, when resonators are combined with other devices, they occupy a large area on the layout of the circuit substrate. Summary of the invention

[0004] The embodiments of the present application provide a resonator, a filter, and a communication device, which are intended to solve the problem that the resonator occupies a large area on the layout of a circuit substrate when used in conjunction with other devices.

[0005] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0006] In one aspect, a resonator is provided, comprising: a substrate and a resonant layer. The resonant layer is located on one side of the substrate, and the resonant layer comprises a first electrode, a second electrode and a piezoelectric layer which are stacked, and the piezoelectric layer is located between the first electrode and the second electrode. At least one of the substrate, the first electrode, the second electrode and the piezoelectric layer is a reference layer, and the edge of the reference layer comprises a first side surface and a second side surface which are adjacent to each other, and the angle between the first side surface and the second side surface and located within the reference layer is a reflex angle.

[0007] The resonator provided in the above-mentioned embodiment of the present application, by setting at least one internal angle as an apparent angle in the reference layer, and then using the adjacent first side surface and the second side surface at the position where the internal angle is the apparent angle to form an area recessed into the reference layer, that is, to form a semi-enclosed area. When the resonator is electrically connected to other devices on the circuit substrate of the filter, the resonator can semi-enclose other devices on the circuit substrate through the semi-enclosed area, so that the resonator and other devices on the circuit substrate are more tightly combined, reducing the area occupied by the resonator and the devices combined therewith on the circuit substrate, thereby improving the layout utilization rate of the circuit substrate. In addition, in the case where the circuit substrate has the same number of devices, the embodiment of the present application reduces the layout area occupied by the device by tightly combining the resonator with other devices on the circuit substrate, which is conducive to reducing the layout area of ​​the circuit substrate.

[0008] In some embodiments, the edge of the reference layer includes a plurality of side surfaces connected end to end in sequence, and any two of the plurality of side surfaces are not parallel. Through the above arrangement, the transverse mode of the bulk acoustic wave generated by the resonator is suppressed, thereby improving the performance of the resonator.

[0009] In some embodiments, at least one side surface includes a plane, and / or at least one side surface includes a curved surface. Through the above configuration, when multiple side surfaces in the resonator provided in the embodiment of the present application are all planes, the working performance of the resonator can be effectively improved; when multiple side surfaces in the resonator provided in the embodiment of the present application have curved surfaces, the flexibility of the resonator to adapt to other devices can be effectively improved.

[0010] In some embodiments, there is a chamfered right angle or a rounded corner between two adjacent side surfaces. Through the above arrangement, the possibility of parallelism between the multiple side surfaces can be further reduced, thereby achieving the suppression of the lateral mode.

[0011] In some embodiments, at least one of the substrate, the first electrode, the second electrode, and the piezoelectric layer is a non-reference layer, and the edge of the reference layer exceeds the edge of the non-reference layer. Through the above arrangement, it is possible to avoid obstruction of the combination of other devices and the resonator on the circuit substrate due to the edge of the film layer of the non-reference layer exceeding the edge of the film layer of the reference layer.

[0012] In some embodiments, the substrate is a reference layer, and in any two film layers in the resonant layer: the edge of the film layer close to the substrate exceeds the edge of the film layer far from the substrate. The above arrangement, by using the substrate as a reference layer, can increase the stability of the bottom support of the resonator, thereby improving the stability of the overall structure of the resonator.

[0013] In some embodiments, the shapes of the orthographic projections of any two of the substrate, the first electrode, the second electrode, and the piezoelectric layer on the reference plane are the same, and the reference plane is perpendicular to the direction of the stacking arrangement of the substrate and the resonant layer. The above arrangement is conducive to reducing the impedance of the anti-resonance frequency of the resonator while ensuring the overall structural stability of the resonator, and improving the effective electromechanical coupling coefficient of the resonator.

[0014] In some embodiments, the reference layer includes: a first side surface, a second side surface, a third side surface, a fourth side surface, a fifth side surface, and a sixth side surface connected end to end in sequence. The angles between the first side surface and the sixth side surface, between the second side surface and the third side surface, and between the fourth side surface and the fifth side surface, and located within the reference layer are obtuse angles. The angles between the third side surface and the fourth side surface, and between the fifth side surface and the sixth side surface, and located within the reference layer are acute angles. Through the above arrangement, the extension direction of the two side surfaces constituting each angle can be changed by changing the angles of each angle, so that the shape of the constructed reference layer is more regular, which is conducive to the combination and splicing with other devices on the layout of the circuit substrate.

[0015] In some embodiments, the substrate has a cavity. The resonant layer and the cavity overlap along a first direction, and the first direction is the direction of the stacking arrangement of the substrate and the resonant layer. Through the above arrangement, a thin film cavity resonator can be formed, and the overlapping area of ​​the resonant layer and the cavity is used to form an effective area as the area that induces the resonance effect.

[0016] In some embodiments, the resonator further includes: a reflective layer. The reflective layer is located between the substrate and the resonant layer, and the resonant layer and the reflective layer overlap along a first direction. The reflective layer includes a high acoustic impedance layer and a low acoustic impedance layer alternately stacked along a first direction, and the first direction is the direction of the stacking arrangement of the substrate and the resonant layer. Through the above arrangement, a solid energy micro-resonator can be formed, and the overlapping area of ​​the resonant layer and the reflective layer is used to form an effective area as an area that induces a resonance effect.

[0017] On the other hand, a filter is provided, the filter comprising: at least one resonator as described above. The filter provided in the embodiment of the present application comprises the resonator as described above, and thus has all the above-mentioned beneficial effects, which will not be described in detail here.

[0018] On the other hand, a communication device is provided, the communication device comprising: the filter as described above and a main board. The main board is connected to the filter. The communication device provided in the embodiment of the present application comprises the filter as described above, and further comprises the resonator as described above, so it has all the above-mentioned beneficial effects, which will not be repeated here.

[0019] In some embodiments, the communication device further includes: a target device. The target device is connected to the mainboard, and the first side surface, the second side surface, and the connection line between the two ends of the first side surface and the second side surface that are opposite to each other in the reference layer in the resonator enclose a first area, and at least part of the target device is located in the first area. Through the above arrangement, the target device can be semi-enclosed by the first area, so that the resonator and the target device are more closely combined, reducing the area occupied by the resonator and the target device on the circuit substrate of the communication device, thereby improving the layout utilization rate of the circuit substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of the structure of a communication device provided in some embodiments of the present application;

[0021] Figure 2 A block diagram of a filter provided in some embodiments of the present application;

[0022] Figure 3A A top view of a resonator in a related art provided for some embodiments of the present application;

[0023] Figure 3B A top view of a resonator in another related art provided for some embodiments of the present application;

[0024] Figure 3C A top view of a resonator in another related art provided for some embodiments of the present application;

[0025] Figure 4 A schematic diagram of a layout of a resonator combined with other devices in the related art provided for some embodiments of the present application;

[0026] Figure 5 A schematic diagram of the structure of a resonator provided in some embodiments of the present application;

[0027] Fig. 6A A top view of a resonator provided in some embodiments of the present application;

[0028] Figure 6B A top view of another resonator provided in some embodiments of the present application;

[0029] Fig. 7A A schematic diagram of a layout of a resonator combined with other devices provided in some embodiments of the present application;

[0030] Figure 7B A schematic diagram of another layout of a resonator combined with other devices provided in some embodiments of the present application;

[0031] Fig. 8A A top view of a reference layer provided for some embodiments of the present application;

[0032] Figure 8B A top view of another reference layer provided for some embodiments of the present application;

[0033] Fig.9A A performance comparison diagram of a resonator provided in some embodiments and a resonator in related art is disclosed;

[0034] Fig. 9B A performance comparison diagram of another resonator provided for disclosing some embodiments and a resonator in the related art;

[0035] Fig.10 A schematic diagram of the structure of another resonator provided in some embodiments of the present application;

[0036] Fig.11A A schematic structural diagram of a thin film cavity resonator provided to disclose some embodiments;

[0037] Fig. 11B A schematic structural diagram of another thin film cavity resonator provided to disclose some embodiments;

[0038] Fig.12 A schematic structural diagram of a solid energy micro-resonator provided to disclose some embodiments;

[0039] Fig.13 A schematic layout diagram of a combination of a resonator and a target device provided in some embodiments of the present application. DETAILED DESCRIPTION

[0040] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments provided by the present application, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present application.

[0041] Unless the context requires otherwise, throughout the specification and claims, the term "including" is to be interpreted as an open, inclusive meaning, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "exemplarily" or "some examples" and the like are intended to indicate that specific features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present application. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics described may be included in any one or more embodiments or examples in any appropriate manner.

[0042] Exemplary embodiments are described herein with reference to cross-sectional views and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are conceivable. Therefore, the exemplary embodiments should not be interpreted as being limited to the shapes of the regions shown herein, but include shape deviations due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device, and are not intended to limit the scope of the exemplary embodiments.

[0043] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0044] The communication device 01 provided in the present application may be a terminal product such as a mobile phone, a tablet computer, or a drone; or, the communication device 01 may also be a communication device such as a base station, a routing device, a server, or a vehicle-mounted device.

[0045] Figure 1 This is a schematic diagram of the structure of a communication device 01 provided in an embodiment of the present application. Figure 1 As shown, the communication device 01 may include a mainboard 02 and a radio frequency front-end module 03 .

[0046] The mainboard 02 may include: at least one memory and at least one processor. The memory may also be referred to as a storage medium or a storage device, etc., for storing software programs. The processor is used to read and execute the software programs in the memory. As a feasible implementation method, the memory may be set independently of the processor; as another feasible implementation method, the memory may also be integrated with the processor.

[0047] The RF front-end module 03 can be installed on the mainboard 02 and connected to the processor on the mainboard 02. The RF front-end module 03 is used for receiving and transmitting RF signals. Among them, the RF signal (Radio Frequency, RF) includes: an electrical signal with a specific frequency. Generally, the RF signal can include: a receiving signal and a transmitting signal. The receiving signal can be called an Rx (Receive) signal, and the transmitting signal can be called a Tx (Transport) signal.

[0048] Among them, the RF front-end module 03 may include an antenna and a RF circuit, wherein the RF circuit is connected to the processor. The RF circuit may include a receiving link and a transmitting link. Further, the RF circuit at least includes: a filter 301, and the filter 301 is connected to the mainboard 02. In the embodiment of the present application, the filter 301 is a device with a frequency selection effect, which can allow specific frequency components in the signal to pass through, while greatly attenuating other frequency components, thereby achieving a frequency selection effect. In the embodiment of the present application, the components of other frequency components can be defined as interference noise. Utilizing this frequency selection effect of the filter 301, interference noise can be reduced, so that the output RF signal is smooth and stable.

[0049] In the embodiment of the present application, the filter 301 may be, but is not limited to, a radio frequency filter, a duplexer, a radio frequency module, and circuit components in other radio frequency circuits.

[0050] Figure 2 301 is a block diagram of a filter 301 provided in some embodiments of the present application. Figure 2 As shown, the filter 301 may include at least one first device 100A and at least one second device 100B. The filter 301 may also include an input port IN, an output port OUT, and a ground terminal, wherein at least one first device 100A may be electrically connected in series between the input port IN and the output port OUT, and the second device 100B may be electrically connected between the first device 100A and the ground terminal. By setting a plurality of first devices 100A, the filter 301 forms a first band stop; by setting a plurality of second devices 100B, the filter 301 forms a second band stop. Through the above settings, the filter 301 has a corresponding passband, so that the signal of the corresponding frequency band can pass.

[0051] For example, Figure 2 The filter 301 shown in the figure may include three first devices 100A and two second devices 100B. Of course, in other embodiments, the number of the first devices 100A and the second devices 100B in the filter 301 may be set accordingly according to actual needs.

[0052] The first device 100A and the second device 100B may both be resonators 100 , wherein the resonator 100 may be a structure in any of the following embodiments.

[0053] Figure 3A A top view of a resonator 200 in a related art provided in some embodiments of the present application; Figure 3B A top view of a resonator 200 in another related art provided for some embodiments of the present application; Figure 3C A top view of a resonator 200 in yet another related art provided for some embodiments of the present application.

[0054] like Figure 3A to Figure 3C As shown, in the related art, the shape of the resonator 200 is mostly a convex polygon, such as a rectangle, a pentagon, etc., or an ellipse, etc.

[0055] Figure 4 Schematic diagram of the layout of the resonator 200 combined with other devices 302 in the related art provided in some embodiments of the present application. Figure 4 As shown, on the layout of the circuit substrate of the filter 301, the shape of the other device 302 matched with the resonator 200 can be circular. For example, the other device 302 can be a metal bump on the circuit substrate for welding, such as a solder joint, a welding pin, etc. At the same time, due to the shape characteristics of the resonator 200 in the related art, the combination between the resonator 200 and the other device 302 in the related art is relatively loose. That is, the structure after the resonator and the other device 302 are combined occupies a large area on the layout of the circuit substrate, resulting in low utilization of the layout area of ​​the filter circuit substrate, and is not conducive to reducing the layout area of ​​the circuit substrate, and is not conducive to realizing the miniaturization and integration of the filter. The above problems are particularly obvious in the corners and edges of the layout of the circuit substrate.

[0056] Figure 5 A schematic structural diagram of a resonator 100 provided in some embodiments of the present application.

[0057] like Figure 5 As shown, the resonator 100 includes a substrate 110 and a resonance layer 120. The resonance layer 120 is located on one side of the substrate 110 and includes a first electrode 121, a second electrode 122 and a piezoelectric layer 123 stacked therebetween. The piezoelectric layer 123 is located between the first electrode 121 and the second electrode 122.

[0058] See also Figure 5 In some embodiments, the first electrode 121 may be disposed on a surface of one side of the substrate 110 , and the second electrode 122 may be disposed on a surface of a side of the piezoelectric layer 123 facing away from the substrate 110 .

[0059] In other embodiments, the positions of the first electrode 121 and the second electrode 122 can be swapped, that is, the second electrode 122 can be disposed on one side surface of the substrate 110 , and the first electrode 121 can be disposed on the side surface of the piezoelectric layer 123 facing away from the substrate 110 .

[0060] For example, the substrate 110 is a supporting layer of the resonator 100 , and the material of the substrate 110 may be a high-resistance material, for example, one or more of single crystal silicon, high-resistance silicon, sapphire or silicon carbide, so as to reduce the leakage of sound wave energy.

[0061] The material of the piezoelectric layer 123 can be a piezoelectric material, and the material of the piezoelectric material can be single crystal or polycrystalline. Compared with polycrystalline materials, single crystal materials have more superior electrical and acoustic properties. For example, the single crystal materials used may include: a combination of one or more of lead zirconate titanate (PZT) piezoelectric ceramics, zinc oxide (ZnO), gallium nitride (GaN), aluminum nitride (AlN) and lithium niobate (LiNbO3), which is not limited in this application. In addition, the thickness of the piezoelectric layer 123 may, for example, include hundreds of nanometers to thousands of nanometers. By adjusting the thickness of the piezoelectric layer 123, the first electrode 121, and the subsequently formed second electrode 122, the frequency formed by the resonator 100 can be adjusted.

[0062] The first electrode 121 and the second electrode 122 may be made of a conductive material, such as one or more of aluminum, copper, titanium, gold, silver, platinum, and molybdenum; or, the conductive material may be other alloy materials, which is not limited in this application. The conductive materials used by the first electrode 121 and the second electrode 122 may be the same or different.

[0063] In some embodiments, the first electrode 121, the piezoelectric layer 123 and the second electrode 122 may be sequentially formed by a deposition method. Further, after the corresponding film layer is formed by deposition, the corresponding film layer may be patterned according to the design layout. The deposition process may include, for example, MOCVD (Metal-organic Chemical Vapor Deposition), MBE (Molecular Beam Epitaxy) or PLD (Pulsed Laser Deposition), etc.

[0064] Through the above arrangement, the mutual conversion between bulk acoustic waves and electrical signals can be realized in the piezoelectric layer 123. For example, when there is an electric field between the first electrode 121 and the second electrode 122, bulk acoustic waves are generated inside the piezoelectric layer 123 due to the voltage inside the piezoelectric layer 123, and the conversion of electrical energy into mechanical energy (energy generated by bulk acoustic waves) can be realized. When the bulk acoustic waves propagate inside the piezoelectric layer 123, positive and negative charges will appear on the surface of the piezoelectric layer 123, thereby generating electrical signals and realizing the conversion of mechanical energy into electrical energy. The above process can be called the piezoelectric effect.

[0065] Furthermore, the resonator 100 can use bulk acoustic waves to achieve frequency selection of electrical signals. For example, when the piezoelectric layer 123 vibrates under the action of voltage, bulk acoustic waves that are far different from the natural frequency are gradually attenuated, while bulk acoustic waves that are the same as or close to the fixed frequency are retained. Therefore, the retained bulk acoustic waves are relatively pure signals. The piezoelectric layer 123 resonates under the action of the bulk acoustic wave of a fixed frequency, so the electrical signal generated at the resonant frequency (the resonant frequency is equal to the natural frequency) is also an electrical signal with a relatively pure frequency, thereby achieving frequency selection of the electrical signal.

[0066] Fig. 6A A top view of a resonator 100 provided in some embodiments of the present application; Figure 6B A top view of another resonator 100 provided in some embodiments of the present application.

[0067] like Figure 6A to Figure 6B As shown, in some embodiments, at least one of the substrate 110, the first electrode 121, the second electrode 121 and the piezoelectric layer 123 is a reference layer 130, the edge of the reference layer 130 includes an adjacent first side surface 131 and a second side surface 132, and the angle A between the first side surface 131 and the second side surface 132 and located within the reference layer 130 is a reflex angle.

[0068] In the embodiment of the present application, the first electrode 121, the piezoelectric layer 123 and the second electrode 122 are patterned to obtain film layers of different shapes. Among all the film layers including the substrate 110, a film layer having an internal angle of an apparent angle can be used as a reference layer 130. For example, the apparent angle A refers to the angle between the two side surfaces constituting the apparent angle A being greater than 180°, wherein the two side surfaces of the apparent angle A are respectively the adjacent first side surface 131 and the second side surface 132.

[0069] Please continue to refer to Figure 5 , Fig. 6A and Figure 6B , projecting onto the reference surface along the stacking direction Z, to obtain the orthographic projection formed by the resonator 100, wherein the stacking direction Z is the direction of the stacking arrangement of the substrate 110 and the resonant layer 120. In the embodiment of the present application, it can be seen from the orthographic projection of the resonator 100 that the internal angle A of the reference layer 130 is a position of a reflex angle, and the adjacent first side surface 131 and the second side surface 132 form an area recessed into the reference layer 130, that is, a semi-enclosed area is formed.

[0070] Among them, the position and number of the reference layer 130 can be determined according to the shape of other devices 302 (for example, solder joints or other resonators on the circuit substrate, etc.) that are matched with the resonator 100. The present application does not limit the position and number of the reference layer 130, that is, the reference layer 130 can be any one or more of the substrate 110, the first electrode 121, the second electrode 121 and the piezoelectric layer 123.

[0071] Example, reference Fig. 6A , the reference layer 130 may be the substrate 110. Projection is made on the reference surface along the stacking direction Z, and the edge of the orthographic projection of the reference layer 130 on the reference surface is obtained, which is located outside the edge of the orthographic projection of the non-reference layer (i.e., other film layers except the reference layer 130) of the resonator 100 on the reference surface. At this time, the first side surface 131 and the second side surface 132 forming the superior angle on the substrate 110 (reference layer 130) can half surround the solder joint on the circuit substrate, thereby shortening the distance between the substrate 110 and the solder joint, thereby reducing the layout area of ​​the circuit substrate occupied by the resonator 100 and the solder joint.

[0072] Alternatively, when the height of the solder joint is less than or equal to the thickness of the film layer of the substrate 110, the edge of the orthographic projection of the substrate 110 on the reference surface may be located within the edge of the orthographic projection of the non-reference layer on the reference surface. In this case, the substrate 110 may also half-surround the solder joint to reduce the layout area of ​​the circuit substrate occupied by the resonator 100 and the solder joint.

[0073] In other examples, the number of reference layers 130 may be multiple, the edges of the orthographic projections of the multiple reference layers 130 on the reference surface may overlap, and the edges of the orthographic projections of the multiple reference layers 130 on the reference surface are all located outside the edges of the orthographic projections of the non-reference layers on the reference surface.

[0074] In some other examples, refer to Figure 6B , all film layers of the resonator 100 can be the reference layer 130 .

[0075] The above configuration can flexibly adjust the position and quantity of the reference layer 130 , thereby achieving combination and electrical connection with devices of various shapes, thereby improving the layout flexibility of the resonator 100 on the circuit substrate of the filter 301 .

[0076] Fig. 7A A schematic diagram of a layout of a resonator 100 combined with other devices 302 provided in some embodiments of the present application; Figure 7B A schematic diagram of a layout of another resonator 100 combined with other devices 302 provided in some embodiments of the present application.

[0077] Fig. 7A and Figure 7BSchematic diagrams of the layout after the resonator 100 is combined with the solder joints or other resonators on the circuit substrate are shown respectively. Figure 7A to Figure 7B As shown, when the resonator 100 is electrically connected to the solder joints or other resonators on the circuit substrate of the filter 301, the resonator 100 can semi-enclose the solder joints or other resonators on the circuit substrate through the semi-enclosed area, thereby reducing the distance between the resonator 100 and the solder joints or other resonators on the circuit substrate, thereby reducing the layout area occupied by the resonator 100 and the solder joints or other resonators combined therewith on the circuit substrate, and improving the layout utilization rate of the circuit substrate of the filter 301.

[0078] Moreover, when the circuit substrate has the same number of devices, the embodiment of the present application reduces the layout area occupied by the devices by tightly combining the resonator 100 with other devices 302 on the circuit substrate, which is beneficial to reducing the layout area of ​​the circuit substrate, and further beneficial to miniaturization and integration of the filter 301.

[0079] Please continue reading Figure 6B In some embodiments, the edge of the reference layer 130 includes a plurality of side surfaces connected end to end in sequence, and any two of the plurality of side surfaces are not parallel.

[0080] It is understandable that there are two transmission modes of body acoustic waves in BAW resonators, namely longitudinal waves (longitudinal modes) and transverse waves (transverse modes). The propagation speeds of these two sound waves are different. Generally, the propagation speed of the longitudinal mode is greater than the propagation speed of the transverse mode. Therefore, the two different transmission modes will produce different resonant responses. Among them, the sound waves propagating longitudinally (that is, the stacking direction Z) induce resonance effects, while the sound waves propagating transversely (perpendicular to the stacking direction Z) dissipate the energy inside the system and excite additional stray modes. Therefore, in practical applications, BAW resonators always tend to use the longitudinal mode of body acoustic waves, and the transverse mode needs to be suppressed.

[0081] For the resonator 100 , if the film layer of the resonator 100 has two or more parallel side surfaces, the lateral mode will be amplified, thereby affecting the performance of the resonator 100 .

[0082] Fig. 8A A top view of a reference layer 130 provided for some embodiments of the present application; Figure 8B A top view of another reference layer 130 provided for some embodiments of the present application.

[0083] See also Figure 6B ,like Fig. 8A and Figure 8BIn the embodiment of the present application, when projecting onto the reference surface along the stacking direction Z, any two sides of the orthographic projection formed by the reference layer 130 are not parallel, that is, any two side surfaces of the film edge of the reference layer 130 are not parallel. This arrangement can reduce the possibility of the transverse mode sound wave forming resonance in the resonator 100, thereby achieving the suppression of the transverse mode.

[0084] In some embodiments, at least one side surface includes a flat surface, and / or at least one side surface includes a curved surface.

[0085] In the embodiment of the present application, the edge of the reference layer 130 includes a plurality of side surfaces connected end to end in sequence, wherein the side surfaces may be flat or curved. Fig. 8A , when the multiple side surfaces are all planes, the orthographic projection of the reference layer 130 on the reference surface is a concave polygon. A concave polygon means that among all the sides constituting the figure, there is one side, and when the side is infinitely extended to both ends of its line segment to form a straight line, the remaining sides are not on the same side of the straight line. In addition, among the internal angles of the concave polygon, there is at least one internal angle that is a reflex angle.

[0086] Fig.9A A performance comparison diagram of a resonator 100 provided in an embodiment of the present application and a resonator in the related art; Fig. 9B This is a performance comparison chart of another resonator 100 provided in an embodiment of the present application and a resonator in the related art.

[0087] In the embodiment of the present application, when the orthographic projection formed by the reference layer 130 on the reference plane is a concave polygon, the performance of the resonator 100 is compared with the performance of the resonator in the related art. FIG. 9A to FIG. 9B As shown. Among them, Fig.9A The horizontal axis is piston width, which is the displacement width of the edge of the second electrode 122 of the resonator 100; the vertical axis is the impedance Z at the anti-resonance frequency P ; Fig. 9B The horizontal axis is piston width, which is the displacement width of the edge of the second electrode 122 of the resonator 100; Fig. 9B The ordinate is the effective electromechanical coupling coefficient K 2 .also, FIG. 9A to FIG. 9B The physical meanings represented by other parameters are as follows: P1 represents the performance curve of the resonator 100 whose orthographic projection of the reference layer 130 is a concave polygon in the embodiment of the present application; P2 represents the performance curve of the resonator whose orthographic projection is a convex polygon in the related art.

[0088] Obviously, see FIG. 9A to FIG. 9BIt can be concluded that, in the case where the relevant parameters of the resonator 100 in the implementation of the present application are the same as those of the resonator in the related art, after the film structure of the resonator 100 is changed in the embodiment of the present application, that is, after the reference layer 130 whose orthographic projection is a concave polygon is provided, the effective electromechanical coupling coefficient K of the resonator 100 in the embodiment of the present application is 2 In addition, compared with the resonator in the related art, the impedance Z of the anti-resonance frequency of the resonator 100 in the embodiment of the present application is P Decreased (for example, Z P down 10-15%).

[0089] In summary, according to the test results, it can be concluded that in the embodiment of the present application, the overall performance of the resonator 100 is better than that of the resonator in the related art. That is to say, in the embodiment of the present application, after providing the reference layer 130 whose orthographic projection is a concave polygon, the working performance of the resonator 100 can be improved.

[0090] Please continue reading Figure 8B When multiple side surfaces have curved surfaces, it is beneficial to smooth the graphic structure formed by the multiple side surfaces of the resonator 100, and then when the resonator 100 is combined with other devices 302 in the circuit substrate of the filter 301, it is beneficial to reduce the distance between the combined resonator 100 and other devices 302, and reduce the layout area occupied by the combined resonator 100 and other devices 302 on the circuit substrate. In addition, compared with the case where the side surface of the resonator 100 is a plane, the curved side surface is more flexible and can be flexibly adapted to devices of different shapes, which can improve the fit between the resonator 100 and other devices 302 in shape, that is, reduce the distance between the combined resonator 100 and other devices 302, and reduce the occupied layout area of ​​the circuit substrate.

[0091] In summary, when multiple side surfaces of the resonator 100 provided in the embodiment of the present application have curved surfaces, the flexibility of the adaptation of the resonator 100 and other devices 302 can be effectively improved, and the layout area of ​​the circuit substrate occupied by the resonator 100 and other devices 302 after being combined can be reduced, thereby improving the layout utilization of the circuit substrate, which is conducive to further miniaturization and integration of the filter 301.

[0092] In some embodiments, two adjacent side surfaces have a chamfered angle or a rounded angle therebetween.

[0093] Please continue reading Figure 8BIn the embodiment of the present application, the angle formed between each two adjacent side surfaces in the reference layer 130 of the resonator 100 is chamfered. For example, the chamfer may include a chamfered right angle or a rounded angle, that is, the angle formed between the two adjacent side surfaces after chamfering is processed and cut into an inclined surface or an arc surface. By chamfering, the possibility of parallelism between multiple side surfaces can be further reduced, thereby achieving the suppression of lateral modes. In addition, chamfering the angle formed by the two adjacent side surfaces in the resonator 100, which is too sharp or protruding, is beneficial to improve the compactness of the combination of the resonator 100 and other devices 302 on the circuit substrate of the filter 301 when the resonator 100 is combined with other devices 302 on the circuit substrate of the filter 301. At the same time, the layout area on the circuit substrate is reduced, and the layout utilization rate of the circuit substrate is improved, which is conducive to further miniaturization and integration of the filter 301. For example, when the angle formed by two adjacent side surfaces of the resonator 100 is chamfered, the angle may be chamfered to a right angle and / or rounded.

[0094] In some embodiments, at least one of the substrate 110 , the first electrode 121 , the second electrode 122 , and the piezoelectric layer 123 is a non-reference layer, and an edge of the reference layer 130 exceeds an edge of the non-reference layer.

[0095] Please continue reading Figure 5 In the embodiment of the present application, the reference layer 130 exists at a position where the inner A is a superior angle, and the adjacent first side surface 131 and the second side surface 132 form an area recessed toward the inside of the reference layer 130, so that the area recessed toward the inside of this position can be used as a semi-enclosed area, and then the edge of the film layer where the semi-enclosed area exists is closely assembled with the surrounding devices, so as to reduce the area occupied by the resonator 100 and the devices assembled by the combination thereof on the layout of the circuit substrate, thereby improving the layout utilization rate of the circuit substrate.

[0096] Among them, in the embodiment of the present application, the edge of the film layer of the reference layer 130 of the resonator 100 exceeds the edge of the film layer of the non-reference layer. In this way, when the resonator 100 is combined with other devices 302 on the circuit substrate, the shape of the non-reference layer is prevented from interfering with the combination of the resonator 100 and other devices 302 on the circuit substrate. In other words, when the resonator 100 is combined with other devices 302 on the circuit substrate, the edge of the film layer of the non-reference layer is prevented from shielding the edge of the film layer of the semi-enclosed area on the reference layer 130 due to the edge of the film layer of the non-reference layer exceeding the edge of the film layer of the reference layer 130, thereby preventing the other devices 302 on the circuit substrate combined with the resonator 100 from entering the semi-enclosed area of ​​the reference layer 130, resulting in a large gap between the resonator 100 and the other devices 302, a large area of ​​the circuit substrate is occupied, and a reduced layout utilization rate of the circuit substrate.

[0097] In summary, in the embodiment of the present application, the edge of the film layer of the reference layer 130 of the resonator 100 exceeds the edge of the film layer of the non-reference layer, which is beneficial for the resonator 100 to enter the semi-enclosed area of ​​the reference layer 130 through the other devices 302 when combined with other devices 302 on the circuit substrate, thereby realizing a close combination of the resonator 100 and the other devices 302, reducing the area occupied by the combined resonator 100 and the other devices 302 on the circuit substrate, and facilitating further reduction of the layout area of ​​the circuit substrate, thereby promoting further miniaturization and integration of the filter 301.

[0098] In some embodiments, the substrate 110 is the reference layer 130 , and in any two film layers of the resonant layer 120 , an edge of the film layer close to the substrate 110 exceeds an edge of the film layer far from the substrate 110 .

[0099] Fig.10 A schematic diagram of the structure of another resonator 100 provided in some embodiments of the present application.

[0100] like Fig.10 As shown, the film areas of the substrate 110, the first electrode 121, the piezoelectric layer 123, and the second electrode 122 in the resonator 100 decrease in sequence along the stacking direction Z, and the substrate 110 is used as the reference layer 130, and the film edge of the substrate 110 will exceed the edges of other film layers. In the embodiment of the present application, by using the substrate 110 as the reference layer 130, the stability of the bottom support of the resonator 100 can be increased, thereby improving the stability of the overall structure of the resonator 100.

[0101] In addition, the resonator 100 is structurally formed by stacking multiple film layers in sequence along the stacking direction Z. As the number of film layer stacking layers increases, the stress generated by the process will cause the center of gravity between adjacent film layers to shift. In the embodiment of the present application, between the multiple film layers included in the resonance layer 120, in addition to the film layer area decreasing in sequence along the stacking direction Z, the edge of the film layer close to the substrate 110 of the two adjacent film layers exceeds the edge of the film layer away from the substrate 110. With this arrangement, during the stacking of two adjacent film layers, even if the center of gravity shifts, the film layer close to the substrate 110 can still provide sufficient support to the film layer away from the substrate 110.

[0102] For example, in the process of forming the piezoelectric layer 123 on the surface of the side of the first electrode 121 away from the substrate 110, the center of gravity of the piezoelectric layer 123 will be offset under the action of stress, thereby moving away from the position of the center of gravity of the first electrode 121, resulting in a change in the center of gravity of the stacked structure formed by the first electrode 121 and the piezoelectric layer 123. However, since the film area of ​​the first electrode 121 is larger than the film area of ​​the piezoelectric layer 123, the distance of the center of gravity offset between the first electrode 121 and the piezoelectric layer 123 can be effectively reduced, thereby reducing the possibility of the resonator 100 structure being unstable due to the center of gravity offset. In addition, the edge of the film layer of the first electrode 121 exceeds the edge of the film layer of the piezoelectric layer 123. Even if the center of gravity position of the piezoelectric layer 123 is offset, the first electrode 121 can still provide sufficient support force to the entire piezoelectric layer 123, thereby ensuring the stability of the stacked structure formed by the first electrode 121 and the piezoelectric layer 123, thereby improving the stability of the overall structure of the resonator 100.

[0103] Please continue reading Figure 6B In some embodiments, the shapes of the orthographic projections of any two membrane layers among the substrate 110 , the first electrode 121 , the second electrode 122 and the piezoelectric layer 123 on the reference plane are the same, and the reference plane is perpendicular to the direction of the stacking arrangement of the substrate 110 and the resonant layer 120 .

[0104] In the embodiment of the present application, projection is made on the reference surface along the stacking direction Z, and the orthographic projections of any two of the multiple film layers of the resonator 100 on the reference surface have the same shape. In combination with the above embodiment, the edge of the film layer of the substrate 110 exceeds the edge of the film layer of the resonance layer 120, and in any two film layers of the resonance layer 120: the edge of the film layer close to the substrate 110 exceeds the edge of the film layer far from the substrate 110, and the orthographic projection of the resonator 100 is obtained as follows: Figure 6B Such a configuration is beneficial to reduce the impedance Z of the anti-resonance frequency of the resonator 100 while ensuring the overall structural stability of the resonator 100. P , and improve the effective electromechanical coupling coefficient K of the resonator 100 2 Among them, the effective electromechanical coupling coefficient K 2 It is used to indicate the relative frequency between the series resonant frequency and the parallel resonant frequency of the resonator 100 , and also indicates the bandwidth of the resonator 100 .

[0105] Please continue reading Figure 6BIn some embodiments, the reference layer 130 includes: a first side surface 131, a second side surface 132, a third side surface 133, a fourth side surface 134, a fifth side surface 135 and a sixth side surface 136 connected end to end in sequence, and the angles between the first side surface 131 and the sixth side surface 136, between the second side surface 132 and the third side surface 133, and between the fourth side surface 134 and the fifth side surface 135, and located within the reference layer 130 are obtuse angles; the angles between the third side surface 133 and the fourth side surface 134, and between the fifth side surface 135 and the sixth side surface 136, and located within the reference layer 130 are acute angles.

[0106] In the embodiment of the present application, the reference layer 130 may include six side surfaces connected end to end in sequence, and each two adjacent side surfaces have an angle located within the reference layer 130. For example, after the six side surfaces of the reference layer 130 are connected end to end, six angles are formed, wherein, except for the angle between the first side surface 131 and the second side surface 132 which is a superior angle, the remaining angles are divided into three obtuse angles and two internal angles, and the obtuse angles and the internal angles are alternately distributed in sequence. In this way, the extension direction of the two side surfaces constituting each angle can be changed by changing the angles of each angle, so that the shape of the constructed reference layer 130 is more regular, which is conducive to the combination and splicing with other devices 302 on the layout of the circuit substrate.

[0107] In addition, in practical applications, the position of the resonator 100 on the layout of the circuit substrate of the filter 301 is mostly at the edge or corner. In the embodiment of the present application, by setting the angle between the fourth side surface 134 and the fifth side surface 135, and located within the reference layer 130, as an obtuse angle, the distance between the angle and the edge or corner of the circuit substrate can be effectively reduced, thereby shortening the distance between the resonator 100 and the edge or corner of the circuit substrate, thereby avoiding the waste of the layout area of ​​the circuit substrate caused by the resonator 100, and facilitating the placement of subsequent devices on the layout of the circuit substrate, thereby improving the utilization rate of the layout of the circuit substrate. By improving the utilization rate of the layout of the circuit substrate, the layout area of ​​the circuit substrate can be reduced when the filter 301 includes the same number of devices, thereby facilitating the miniaturization and integration of the filter 301.

[0108] Fig.11A A schematic structural diagram of a thin film cavity resonator provided to disclose some embodiments; Fig. 11B A schematic structural diagram of another thin film cavity resonator is provided to disclose some embodiments.

[0109] like Figure 11A to Figure 11BAs shown, in some embodiments, the substrate 110 has a cavity 111. The resonant layer 120 and the cavity 111 overlap along a first direction Z, and the first direction Z is a direction in which the substrate 110 and the resonant layer 120 are stacked.

[0110] In the embodiment of the present application, the substrate 110 has a cavity 111. For example, the cavity 111 may have at least one opening. Fig.11A , when the cavity 111 has an opening, the opening is located on a side of the substrate 110 close to the resonant layer 120; see Fig. 11B When the cavity 111 has two openings, the two openings are relatively arranged in the first direction Z, and any one of the two openings is arranged on a side of the substrate 110 close to the resonance layer 120, and the other opening is arranged on a side of the substrate 110 away from the resonance layer 120. The first direction Z is the direction in which the substrate 110 and the resonance layer 120 are stacked.

[0111] At this time, the resonator 100 having the cavity 111 on the substrate 110 can constitute a free-standing bulk acoustic resonator (FBAR), wherein the resonant layer 120 and the cavity 111 overlap along the first direction Z, that is, the first electrode 121, the second electrode 122 and the piezoelectric layer 123 overlap with the cavity 111 along the first direction Z, so that the overlapping area constitutes an effective area as an area for inducing a resonance effect.

[0112] In actual application, it is necessary to apply electric signals to the first electrode 121 and the second electrode 122 respectively. When the resonator 100 receives an external voltage signal, the piezoelectric layer 123 between the first electrode 121 and the second electrode 122 will produce mechanical deformation under the inverse piezoelectric effect, so that the piezoelectric layer 123 changes with the change of the external voltage signal. For example, the piezoelectric layer 123 can expand or contract with the change of the external voltage signal.

[0113] The mechanical deformation of the piezoelectric layer 123 can generate vibration, which in turn excites a bulk acoustic wave propagating along the stacking direction Z in the film layer where the piezoelectric layer 123 is located, and reflects back when the bulk acoustic wave propagates to the interface between the first electrode 121 and the second electrode 122 and the air, and repeatedly reflects back and forth in the resonant layer 120 of the resonator 100 to form an oscillation. Furthermore, when the wavelength of the bulk acoustic wave propagating in the resonant layer 120 of the resonator 100 reaches a certain length, a standing wave oscillation is formed. Among them, bulk acoustic waves have two transmission modes, namely longitudinal waves and transverse waves. The propagation speeds of these two sound waves are different. Generally, the propagation speed of the longitudinal mode is greater than the propagation speed of the transverse mode. Therefore, the two different transmission modes will produce different resonant responses. Among them, the sound waves propagating longitudinally (that is, parallel to the first direction Z) induce a resonance effect, while the sound waves propagating transversely (that is, perpendicular to the first direction Z) will dissipate the energy inside the system and excite additional stray modes, which need to be suppressed.

[0114] Fig.12 Disclosed are schematic structural diagrams of a solid energy micro-resonator provided in some embodiments.

[0115] like Fig.12 As shown, in some embodiments, the resonator 100 further includes: a reflective layer 140, which is located between the substrate 110 and the resonance layer 120, and the resonance layer 120 and the reflective layer 140 overlap along a first direction Z, and the reflective layer 140 includes a high acoustic impedance layer 141 and a low acoustic impedance layer 142 alternately stacked along the first direction Z, and the first direction Z is the direction of the stacking arrangement of the substrate 110 and the resonance layer 120.

[0116] In the embodiment of the present application, a reflective layer 140 is further provided between the substrate 110 and the resonant layer 120, and the reflective layer 140 includes a high acoustic impedance layer 141 and a low acoustic impedance layer 142 alternately stacked along a first direction Z. The first direction Z is the direction in which the substrate 110 and the resonant layer 120 are stacked. For example, the material of the high acoustic impedance layer 141 can be a combination of one or more of aluminum, titanium, silicon, molybdenum, tungsten, aluminum nitride (AlN), and silicon dioxide (SiO2); the material of the low acoustic impedance layer 142 can also be a combination of one or more of aluminum nitride (AlN), aluminum, titanium, silicon, silicon dioxide (SiO2), molybdenum, and tungsten, which is not limited in the present application.

[0117] At this time, the resonator 100 with the reflective layer 140 can constitute a solid-mounted micro-resonator (SMR). Among them, the resonant layer 120 and the reflective layer 140 overlap along the first direction Z, that is, the first electrode 121, the second electrode 122 and the piezoelectric layer 123 overlap with the reflective layer 140 along the first direction Z, so that the overlapping area is used to form an effective area, which is the area that induces the resonance effect. Compared with the thin film cavity resonator in the above embodiment, the solid-mounted micro-resonator in this embodiment does not need to make a cavity on the substrate 110, so it has a more stable structure, and after removing the etching process for preparing the cavity, the preparation success rate of the solid-mounted micro-resonator is also higher than that of the thin film cavity resonator.

[0118] In actual application, the main difference between the solid energy micro-resonator and the thin film cavity resonator lies in the structure of reflecting sound waves, that is, the thin film cavity resonator in the above embodiment uses a cavity structure constructed in the substrate 110 below the resonance layer 120 to reflect sound waves and limit energy. The solid energy micro-resonator uses a reflection layer composed of a high acoustic impedance layer 141 and a low acoustic impedance layer 142 constructed between the resonance layer 120 and the substrate 110 to reflect sound waves and limit energy.

[0119] The resonator 100 provided in some of the above embodiments may be combined with and electrically connected to other devices 302 on the circuit substrate in the filter 301 , or may be combined with and electrically connected to a target device in the communication device 01 .

[0120] In some embodiments, the communication device 01 further includes: a mainboard 02 and a target device 303. The target device 303 is connected to the mainboard 02, and the first side surface 131, the second side surface 132, and the connection line between the two ends of the first side surface 131 and the second side surface 132 that are opposite to each other in the reference layer 130 in the resonator 100 enclose a first area 150, and at least a portion of the target device 303 is located in the first area 150.

[0121] In the embodiment of the present application, a projection is made on the reference surface along the stacking direction Z to obtain the orthographic projection corresponding to the resonator 100. It can be seen from the orthographic projection of the resonator 100 that the reference layer 130 of the resonator 100 has an internal angle A that is a superior angle, and the position corresponding to the superior angle A is surrounded by the adjacent first side surface 131, the second side surface 132, and the line connecting the two ends of the first side surface 131 and the second side surface 132 that are opposite to each other to form a structure that is recessed into the reference layer 130, thereby forming a semi-enclosed first area 150 at this position. Among them, the line connecting the two ends of the first side surface 131 and the second side surface 132 that are opposite to each other can be a straight line.

[0122] Fig.13 A schematic diagram of a layout of a combination of a resonator 100 and a target device 303 provided in an embodiment of the present application.

[0123] Exemplarily, when the orthographic projections of the first side surface 131 and the second side surface 132 on the reference plane are straight lines, the reference plane Fig.13 , the first area is triangular. In the embodiment of the present application, when the resonator 100 is matched with the target device 303 on the circuit substrate of the communication device 01, the resonator 100 can semi-enclose the target device 303 on the circuit substrate through the semi-enclosed first area 150, so that the resonator 100 and the target device 303 on the circuit substrate can be tightly combined, thereby reducing the area occupied by the resonator 100 and the overall structure after the combination with the target device 303 on the circuit substrate, thereby improving the layout utilization of the circuit substrate. Moreover, in the case where the circuit substrate of the communication device 01 has the same number of devices, the embodiment of the present application reduces the layout area occupied by the overall structure after the combination by tightly combining the resonator 100 with the target device 303 on the circuit substrate, which is beneficial to reducing the layout area of ​​the circuit substrate, and thus conducive to miniaturization and integration of the communication device 01.

[0124] In some other examples, the orthographic projections of the first side surface 131 and the second side surface 132 on the reference plane may be curves, and in this case, the first region 150 is quasi-triangular, that is, two adjacent sides of the quasi-triangle are arc-shaped.

[0125] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A resonator, characterized in that: include: substrate; A resonance layer, located on one side of the substrate, the resonance layer comprising a first electrode, a second electrode and a piezoelectric layer which are stacked; The piezoelectric layer is located between the first electrode and the second electrode; Among them, at least one of the substrate, the first electrode, the second electrode and the piezoelectric layer is a reference layer, the edge of the reference layer includes an adjacent first side surface and a second side surface, and the angle between the first side surface and the second side surface and located within the reference layer is a reflex angle.

2. The resonator according to claim 1, characterized in that The edge of the reference layer includes a plurality of side surfaces connected end to end in sequence, and any two of the plurality of side surfaces are not parallel.

3. The resonator according to claim 2, characterized in that At least one of the side surfaces comprises a plane, and / or at least one of the side surfaces comprises a curved surface.

4. The resonator according to claim 2 or 3, characterized in that There is a chamfered angle or a rounded angle between two adjacent side surfaces.

5. The resonator according to any one of claims 1 to 4, characterized in that: At least one of the substrate, the first electrode, the second electrode, and the piezoelectric layer is a non-reference layer, and an edge of the reference layer exceeds an edge of the non-reference layer.

6. The resonator according to any one of claims 1 to 5, characterized in that: The substrate is the reference layer, and in any two film layers in the resonance layer: an edge of the film layer close to the substrate exceeds an edge of the film layer far from the substrate.

7. The resonator according to claim 6, characterized in that The orthographic projections of any two of the substrate, the first electrode, the second electrode, and the piezoelectric layer on a reference plane have the same shape, and the reference plane is perpendicular to the direction in which the substrate and the resonant layer are stacked.

8. The resonator according to claim 6 or 7, characterized in that The reference layer includes: the first side surface, the second side surface, the third side surface, the fourth side surface, the fifth side surface and the sixth side surface which are connected end to end in sequence, and the angles between the first side surface and the sixth side surface, between the second side surface and the third side surface, and between the fourth side surface and the fifth side surface, which are located within the reference layer, are obtuse angles; the angles between the third side surface and the fourth side surface, and between the fifth side surface and the sixth side surface, which are located within the reference layer, are acute angles.

9. The resonator according to any one of claims 1 to 8, characterized in that: The substrate has a cavity; The resonant layer and the cavity overlap along a first direction, and the first direction is a direction in which the substrate and the resonant layer are stacked.

10. The resonator according to any one of claims 1 to 8, characterized in that: Also includes: A reflective layer is located between the substrate and the resonance layer, and the resonance layer and the reflective layer overlap along a first direction. The reflective layer includes a high acoustic impedance layer and a low acoustic impedance layer alternately stacked along the first direction. The first direction is the direction in which the substrate and the resonance layer are stacked.

11. A filter, characterized in that: include: At least one resonator as claimed in any one of claims 1 to 10.

12. A communication device, characterized in that: include: The filter as claimed in claim 11; A main board is connected to the filter.

13. The communication device according to claim 12, characterized in that Also includes: A target device is connected to the main board, a first side surface, a second side surface, and a line connecting two opposite ends of the first side surface and the second side surface of a reference layer in the resonator enclose a first area, and at least a portion of the target device is located in the first area.

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