High Q electroacoustic resonator

Abstract

Aspects include high Q resonator devices and related systems and methods. In one aspect, a device includes a first bus (860) and a second bus (862). The device includes a first electrode finger (810, 910) coupled to the first bus and extending in a first direction toward the second bus without contacting the second bus, wherein the first electrode finger includes a finger tip (834, 935) having a first shape; a first stub electrode finger (950) coupled to the second bus and extending in a second direction opposite the first direction toward the finger tip of the first electrode finger, wherein the first stub electrode finger includes a first end coupled to the second bus and a second end, and wherein the second end includes a stub tip having a second shape (955) different from the first shape.

Description

Technical Field

[0001] This disclosure relates in general to wireless communication, and more specifically to high-frequency filters that can be implemented together with electroacoustic resonators. Background Technology

[0002] Electronic devices include traditional computing devices such as desktop computers, laptops, tablets, smartphones, wearable devices such as smartwatches, and internet servers. These diverse electronic devices provide human users with information, entertainment, social interaction, security, safety, productivity, transportation, manufacturing, and other services. Many of the functions of these diverse electronic devices rely on wireless communication. Wireless communication systems and devices are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, and broadcasting. These systems can support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such systems include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, and Orthogonal Frequency Division Multiple Access (OFDMA) systems (e.g., Long Term Evolution (LTE) systems or New Radio (NR) systems).

[0003] The wireless communication transceivers used in these electronic devices typically include multiple radio frequency (RF) filters for filtering signals at specific frequencies or frequency ranges. Electroacoustic devices (e.g., "acoustic filters") are used in many applications to filter high-frequency (e.g., typically greater than 100 MHz) signals. Using piezoelectric materials as the vibrating medium, acoustic resonators operate by converting electrical signal waves propagating along an electrical conductor into sound waves propagating via the piezoelectric material. Sound waves propagate at speeds significantly smaller than those of electromagnetic waves. Generally, the speed of wave propagation is proportional to the wavelength of the wave. Therefore, after converting an electrical signal into an acoustic signal, the wavelength of the acoustic signal wave is significantly smaller than the wavelength of the electrical signal wave. The resulting smaller wavelength of the acoustic signal allows for the use of smaller filter devices to perform filtering. This permits the use of acoustic resonators in electronic devices with size constraints, such as those listed above (e.g., specifically portable electronic devices such as cellular phones). Summary of the Invention

[0004] This disclosure describes elements of filter circuits for wireless communication systems. As described above, electroacoustic resonators can be used in such filter circuits. In some configurations, harmonics of such resonators may be generated incidentally with desired performance, and these harmonics may interfere with other signals in the wireless communication device. The aspects described herein include structures for suppressing such harmonics.

[0005] In one exemplary example, a wireless communication device is provided. The wireless communication device includes an electroacoustic resonator comprising: a first bus; a second bus; a first electrode finger coupled to the first bus and extending toward the second bus in a first direction without contacting the second bus, wherein the first electrode finger includes a finger tip having a first shape; and a first stub electrode finger coupled to the second bus and extending toward the finger tip of the first electrode finger in a second direction opposite to the first direction, wherein the first stub electrode finger includes a second end and a first end coupled to the second bus, and wherein the second end includes a stub tip having a second shape different from the first shape.

[0006] In some respects, the electroacoustic resonator operates when the first shape is rectangular.

[0007] In some respects, the electroacoustic resonator operates with a first shape comprising a plurality of rectangular stub shapes, the plurality of rectangular stub shapes comprising rectangular shapes.

[0008] In some respects, the electroacoustic resonator operates with the first shape being triangular.

[0009] In some respects, the electroacoustic resonator operates with a first shape comprising a curve intersecting at a point at the tip of the finger.

[0010] In some respects, the electroacoustic resonator operates when the first electrode finger also includes a first piston section located between the first and second segments of the first electrode finger, adjacent to the tip of the finger.

[0011] In some respects, the electroacoustic resonator operates when the first piston section includes a region with increased thickness compared to the thickness of the first section of the first electrode finger.

[0012] In some respects, the electroacoustic resonator operates when the first piston section includes a region with an additional width compared to the width of the first section of the first electrode finger.

[0013] In some aspects, the electroacoustic resonator further includes: a first gap reflector parallel to the first generatrix and extending in a direction different from that of the first electrode fingers, wherein the first gap reflector intersects the first electrode fingers in the gap between the first generatrix and the fingers extending toward the first generatrix.

[0014] In some aspects, the electroacoustic resonator also includes a second gap reflector that extends in a direction different from that of the first stub electrode finger, wherein the second gap reflector intersects the first stub electrode finger in the gap between the second busbar and the first electrode finger.

[0015] In some respects, the electroacoustic resonator operates when the electroacoustic resonator is part of the transmitting or receiving path of a wireless communication device, and wherein the wireless communication device also includes: an antenna; and an amplifier.

[0016] In some aspects, the technology described herein relates to an electroacoustic resonator comprising: an electrode finger including a first end coupled to a busbar and an electrode tip positioned away from the busbar in a direction generally perpendicular to the busbar; the electrode finger further comprising a first segment, a piston segment, and a tip segment; wherein the first segment extends from the first end to a first piston segment interface; wherein the piston segment extends from the first piston segment interface to a second piston segment interface; and wherein the tip segment extends from the second piston segment interface to the electrode tip in a direction perpendicular to the busbar, wherein the width of the tip segment at its widest position is narrower than the width of the first segment at its narrowest position.

[0017] In some respects, electroacoustic resonators operate with a rectangular shape at their tip.

[0018] In some respects, the electroacoustic resonator operates with the tip segment comprising multiple rectangular stub shapes, which include rectangular shapes.

[0019] In some respects, electroacoustic resonators operate with a triangular shape at their tip.

[0020] In some respects, the electroacoustic resonator operates with a curve in the tip segment that intersects at a point at the tip of the finger.

[0021] In some aspects, the electroacoustic resonator also includes: a gap reflector that is parallel to the busbar and extends in a direction different from that of the electrode fingers, wherein the gap reflector intersects the first electrode fingers in a gap between the busbar and the electrode fingers extending toward the busbar without contacting the busbar.

[0022] In some respects, the electroacoustic resonator operates when the electroacoustic resonator is part of the transmitting or receiving path of a wireless communication device, and wherein the wireless communication device also includes: an antenna; and an amplifier.

[0023] In some aspects, the technology described herein relates to a method of manufacturing an electroacoustic resonator, the method comprising: manufacturing a metallization layer mask including: a first electrode finger shape extending in a first direction and having a second end and a first end coupled to a first busbar segment, wherein the second end includes a finger tip having a first shape; and a first stub electrode finger shape extending in a second direction opposite to the first direction toward the finger tip of the first electrode finger shape, wherein the first stub electrode finger shape includes a second end and a first end coupled to a second busbar segment, and wherein the second end includes a stub tip having a second shape different from the first shape; and manufacturing a metallization layer of the electroacoustic resonator using the metallization layer mask.

[0024] In some respects, the techniques described herein relate to a method in which a metallization layer mask includes a pre-distortion pattern for generating a second shape at a second end.

[0025] In some aspects, the apparatus described above may include: a mobile device having a camera for capturing one or more images. In some aspects, the apparatus described above may include: a display for displaying one or more images. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in isolation to define the scope of the claimed subject matter. This subject matter should be understood with reference to the appropriate portions of the entire specification of this patent, any or all of the drawings, and each claim.

[0026] The foregoing, as well as other features and embodiments, will become more apparent from the following description, claims and drawings. Attached Figure Description

[0027] Figure 1A This is a perspective view of an example of an electroacoustic device.

[0028] Figure 1B yes Figure 1A A side view of the electroacoustic equipment.

[0029] Figure 2A This is a top-view illustration of an example electrode structure for an electroacoustic device.

[0030] Figure 2B This is a top-view illustration of another example of the electrode structure of an electroacoustic device.

[0031] Figure 3A This is a perspective view of another example of an electroacoustic device.

[0032] Figure 3B yes Figure 3A A side view of the electroacoustic equipment.

[0033] Figure 4 This is a diagram of the electrode structure of an electroacoustic device, aligned with a graph illustrating the sound velocity distribution in different regions of the electroacoustic device.

[0034] Figure 5A and Figure 5B This is an illustration of an example electrode structure, as shown in the reference. Figure 4 Examples of different specific implementations of the defined trap region.

[0035] Figure 6 This is a representation of a wireless communication device including an electroacoustic resonator, based on the example described herein.

[0036] Figure 7A This is a representation of an electroacoustic resonator based on various aspects of the illustrative harmonic suppression structure described in this article.

[0037] Figure 7B This is a representation of an electroacoustic resonator based on various aspects of the illustrative harmonic suppression structure described in this article.

[0038] Figure 8A This is a representation of an electroacoustic resonator based on various aspects of the illustrative harmonic suppression structure described in this article.

[0039] Figure 8B This is a representation of an electroacoustic resonator based on various aspects of the illustrative harmonic suppression structure described in this article.

[0040] Figure 9A This is a representation of an electroacoustic resonator based on various aspects of the illustrative harmonic suppression structure described in this article.

[0041] Figure 9B This is a representation of an electroacoustic resonator based on various aspects of the illustrative harmonic suppression structure described in this article.

[0042] Figure 9C This is a representation of an electroacoustic resonator based on various aspects of the illustrative harmonic suppression structure described in this article.

[0043] Figure 9D This is a representation of an electroacoustic resonator based on various aspects of the illustrative harmonic suppression structure described in this article.

[0044] Figure 10 It is a representation of a wireless communication device, including an electroacoustic resonator for harmonic suppression, based on the aspects described herein.

[0045] Figure 11The figure illustrates the improvements in the performance of wireless communication devices based on the various aspects described herein, including electroacoustic resonators with harmonic suppression.

[0046] Figure 12 This is a functional block diagram of at least a portion of an example of a simplified wireless transceiver circuit that may employ filter circuitry and associated slotted resonators.

[0047] Figure 13 Transceiver paths, which may include electroacoustic resonators with harmonic suppression, are illustrated according to the aspects described herein.

[0048] Figure 14 This is a diagram illustrating an environment including a wireless communication device based on the aspects described herein, which may include a resonator with harmonic suppression to achieve improved performance. Detailed Implementation

[0049] The detailed description set forth below in conjunction with the accompanying drawings is intended as a description of exemplary embodiments and is not intended to represent the only embodiments in which the invention may be practiced. The term "exemplary" as used throughout this description means "serving as an example, instance, or illustration" and should not be construed as superior to or better than other exemplary embodiments. The detailed description includes specific details for the purpose of providing a thorough understanding of the exemplary embodiments. In some instances, some devices are shown in block diagram form. Drawing elements common in the following drawings may be identified using the same reference numerals.

[0050] Electroacoustic devices employing electrode structures on the surface of piezoelectric materials, such as surface acoustic wave (SAW) resonators, are being designed to cover a wider frequency range (e.g., 500 MHz to 6 GHz), have higher bandwidth (e.g., up to 25%), and exhibit improved efficiency and performance as designs using such devices become more sophisticated. Additionally, such devices can be included in systems supporting transmission, reception, and multiple channels at different frequencies within the same wireless communication device. During operation, such SAW resonators can generate harmonics (e.g., second and third harmonic signals of the primary signal). These harmonics can propagate through parasitic paths to interfere with signals in other signal paths (e.g., second harmonic interference of the signal in the transmit path resonator with the signal in the SAW or bulk acoustic wave (BAW) receive path resonator).

[0051] The aspects described herein include structures within SAW resonators that can suppress certain harmonics using adjusted structures within harmonic resonators, including modifications to the electrode finger tips according to the aspects described herein. Specifically, regions at the edges (e.g., tips) of the metal fingers affect the linearity of the electroacoustic resonator due to nonlinearities (e.g., particularly second-order nonlinearities) originating from the fields in these regions. The aspects described herein modify these regions to reduce second-order nonlinearities and improve device performance. Since the device shape is modified at the electrode tips rather than by changing the size or configuration of the electrode fingers, such improvements can be provided with little or no increase in device area.

[0052] Additional details are provided in the context of the accompanying figures below.

[0053] Figure 1A This is a perspective view of an example of an electroacoustic device 100. The electroacoustic device 100 may be configured as or part of a SAW resonator. In some descriptions herein, the electroacoustic device 100 may be referred to as a SAW resonator. However, other types of electroacoustic devices (e.g., BAW or TFBAR) may exist that can be constructed based on the principles described herein. The electroacoustic device 100 includes an electrode structure 104, which may be referred to as an interdigital transducer (IDT), located on the surface of a piezoelectric material 102. The electrode structure 104 typically includes a first comb-shaped electrode structure and a second comb-shaped electrode structure (conductive and typically metallic), wherein electrode fingers extend from two busbars toward each other and are arranged in an interlocking manner between the two busbars (e.g., in an interdigital arrangement). An electrical signal excited (e.g., by applying an AC voltage) in the electrode structure 104 is converted into an acoustic wave 106, which propagates in a specific direction via the piezoelectric material 102. The acoustic wave 106 is converted back into an electrical signal and provided as an output. In many applications, the piezoelectric material 102 has a specific crystal orientation such that when the electrode structure 104 is arranged relative to the crystal orientation of the piezoelectric material 102, acoustic waves propagate primarily in a direction perpendicular to the fingers (e.g., parallel to the generatrix). In various examples, the circuits described herein with such structures may include micro-electroacoustic filters implemented using microelectromechanical systems (MEMS) technology. MEMS technology includes micro-physical structures that may possess both mechanical (e.g., vibratory or acoustic) component properties and electrical properties. In some examples, MEMS fabrication techniques can be used to construct the resonators described herein to generate structures with dimensions less than one micrometer.

[0054] Figure 1B yes Figure 1A The electroacoustic equipment 100 along Figure 1AThe diagram shows a side view of cross-section 107. The electroacoustic device 100 is exemplified by a simplified layer stack comprising a piezoelectric material 102, with electrode structures 104 disposed on the piezoelectric material 102. The electrode structures 104 are conductive and are typically formed of a metallic material. The piezoelectric material can be formed from a variety of materials such as quartz, lithium tantalate (LiTaO3), lithium niobate (LiNbO3), doped variants of these materials, or other piezoelectric materials. It should be understood that more complex layer stacks comprising layers of various materials are possible within this stack. For example, optionally, a temperature compensation layer 108, indicated by dashed lines, can be disposed above the electrode structures 104. The piezoelectric material 102 can be extended with multiple interconnected electrode structures disposed thereon to form a multi-resonator filter or provide multiple filters. Although not illustrated, when disposed as an integrated circuit component, a capping layer can be disposed above the electrode structures 104. The capping layer is applied such that a cavity is formed between the electrode structures 104 and the lower surface of the capping layer. It may also include electrical vias or bumps that allow components to be electrically connected to connectors on the substrate (e.g., via flip chips or other technologies).

[0055] Figure 2A This is a top-view view of an example of the electrode structure 204a of the electroacoustic device 100. The electrode structure 204a has an IDT 205, which includes a first busbar 222 (e.g., a first conductive segment or conductive trunk) electrically connected to a first terminal 220 and a second busbar 224 (e.g., a second conductive segment or conductive trunk) spaced apart from the first busbar 222 and connected to a second terminal 230. A plurality of conductive fingers 226 are interdigitatedly connected to either the first busbar 222 or the second busbar 224. The fingers 226 connected to the first busbar 222 extend toward the second busbar 224 but are not connected to the second busbar 224, such that a small gap exists between the ends of these fingers 226 and the second busbar 224. Similarly, the fingers 226 connected to the second busbar 224 extend toward the first busbar 222 but are not connected to the first busbar 222, such that a small gap exists between the ends of these fingers 226 and the first busbar 222.

[0056] Along the direction of the generatrix, there exists an overlapping region comprising a central region where a portion of one of the fingers overlaps with a portion of an adjacent finger, as illustrated by central region 225. This overlapping central region 225 may be referred to as a pore, track, or active region, where an electric field is generated between the fingers 226 to allow sound waves to propagate within the central region 225 of the piezoelectric material 102. The periodicity of the fingers 226 is referred to as the pitch of the IDT. The pitch can be indicated in various ways. For example, in some aspects, the pitch may correspond to a magnitude of the distance between the fingers in the central region 225. This distance may be defined, for example, as the distance between the center points of each of these fingers (and when the fingers have a uniform thickness, it is typically measured between the right (or left) edge of one finger and the right (or left) edge of an adjacent finger). In some aspects, the average distance between adjacent fingers can be used as the pitch. The frequency at which the piezoelectric material vibrates within a given stack (e.g., a complete stack including a combination of piezoelectric layers and electrode structures) is the self-resonant (also referred to as the “master resonance”) frequency of the electrode structure 204a. This frequency is determined at least in part by the pitch of the IDT 205 and other characteristics of the electroacoustic device 100.

[0057] An IDT 205 is arranged between two reflectors 228 that reflect sound waves toward the IDT 205 so that the sound waves are converted into electrical signals via the IDT 205 in the illustrated configuration, and loss is prevented (e.g., the sound waves are confined and prevented from escaping). Each reflector 228 has two buses and a grating structure of conductive fingers, each connected to one of the two buses. The pitch of the reflectors may be similar to or the same as the pitch of the IDT 205 to reflect sound waves within the resonant frequency range. However, many configurations are possible.

[0058] When converted back to an electrical signal, the converted electrical signal can be provided as an output, such as one of the first terminal 220 or the second terminal 230, while the other terminal can be used as an input.

[0059] Multiple electrode structures are possible. Figure 2A A single-port configuration can be roughly illustrated. Other two-port configurations are also possible. For example, electrode structure 204a may have an input IDT 205, where each terminal 220 and 230 serves as an input terminal. In this case, an adjacent output IDT (not illustrated) positioned between reflectors 228 and adjacent to the input IDT 205 can be provided to convert the acoustic waves propagating in the piezoelectric material 102 into electrical signals to be provided at the output terminals of the output IDT.

[0060] Figure 2BThis is a top-view view of another example of the electrode structure 204b of the electroacoustic device 100. This dual-mode SAW (DMS) electrode structure 204b is illustrated; the DMS electrode structure is capable of inducing multiple resonances. The electrode structure 204b includes multiple IDTs connected as illustrated, and a reflector 228. The electrode structure 204b is provided to illustrate various electrode structures to which the principles described herein are applicable, including... Figure 2A Electrode structure 204a and Figure 2B Electrode structure 204b.

[0061] It should be understood that although a certain number of fingers 226 are illustrated, the actual number of fingers, as well as the length and width of the fingers 226 and the busbars, may differ in actual implementations. These parameters depend on the specific application of the filter and the desired frequency. Furthermore, the SAW filter may include multiple interconnect electrode structures, each including multiple IDTs to achieve the desired passband (e.g., multiple interconnect resonators or IDTs to form the desired filter transfer function).

[0062] Figure 3A This is a perspective view of another example of an electroacoustic device 300. The electroacoustic device 300 (e.g., which may be configured as a SAW resonator or a portion thereof) is similar to... Figure 1A Electroacoustic device 100, but with a different layer stack. Specifically, electroacoustic device 300 includes a thin piezoelectric material 302 provided on a substrate 310 (e.g., silicon). In some cases, electroacoustic device 300 may be referred to as a thin-film SAW resonator (TF-SAW). Based on the type of piezoelectric material 302 used (e.g., typically having a higher coupling coefficient relative to electroacoustic device 100) and the controlled thickness of piezoelectric material 302, the specific acoustic wave modes excited can be... Figure 1A The sound wave modes in the electroacoustic device 100 are slightly different. Based on the design (layer thickness and material selection, etc.), and... Figure 1A Compared to the electroacoustic device 100, the electroacoustic device 300 may have a higher Q factor. The piezoelectric material 302 may be, for example, lithium tantalate (LiTaO3) or some doped variant. Figure 3A Another example of the piezoelectric material 302 may be lithium niobate (LiNbO3). Generally, the substrate 310 may be substantially thicker than the piezoelectric material 302 (for example, it may be about 50 to 100 times thicker, or more times thicker). The substrate 310 may include other layers (or other layers may be included between the substrate 310 and the piezoelectric material 302).

[0063] Figure 3B yes Figure 3A A side view of the electroacoustic device 300, showing an exemplary layer stack (along section 307). Figure 3BIn the example shown, substrate 310 may include sublayers that may have higher resistance (e.g., relative to other layers, i.e., high resistivity layers), such as substrate sublayer 310-1 (e.g., made of silicon). Substrate 310 may also include a well-rich layer 310-2 (e.g., polycrystalline silicon). Substrate 310 may also include a compensation layer 310-3 (e.g., silicon dioxide (SiO2) or another dielectric material) that can provide temperature compensation and other properties. These sublayers may be considered as part of substrate 310 or as separate layers on their own. A relatively thin piezoelectric material 302 is provided on substrate 310 at a specific thickness to provide a specific acoustic mode (e.g., with...). Figure 1A Compared to the electroacoustic device 100, the thickness of the piezoelectric material 102 is not a critical design parameter exceeding a certain thickness, and compared with... Figure 3A and Figure 3B The piezoelectric material 302 of the electroacoustic device 300 may be thicker than it would typically be. The electrode structure 304 is positioned above the piezoelectric material 302. In addition, in some aspects, one or more layers (not shown) (e.g., a thin passivation layer) may be present above the electrode structure 304.

[0064] Based on the type, thickness, and overall layer stacking of the piezoelectric material, the coupling to the electrode structure 304 and the sound velocity within the piezoelectric material in different regions of the electrode structure 304 can be achieved between different types of electroacoustic devices, such as... Figure 1A Electroacoustic equipment 100 and Figure 3A and Figure 3B The electroacoustic devices vary among the 300 models.

[0065] Figure 4 This is a diagram of a portion of the electrode structure 404 of an electroacoustic device aligned with a graph illustrating the sound velocity distribution in different regions of the electroacoustic device. Figure 4 The electrode structure 404 shows a similarity to the reference. Figure 2A A portion of the described IDT 405 has a first busbar 422, a second busbar 424, and interdigitated fingers 426. Since the angular and frequency positions of transverse acoustic modes depend on the directional acoustic velocity, in one aspect, the transverse velocity distribution within the acoustic track can be designed to reduce transverse acoustic modes and facilitate the excitation of the dominant or fundamental mode. Specifically, the electrode structure 404 (and potentially other layers) can be adjusted in different regions of the electrode structure 404 to adjust the transverse velocity distribution within the acoustic track to reduce transverse acoustic modes.

[0066] Figure 4 The examples illustrate different regions of electrode structure 404, which can be designed or structurally modified to adjust the lateral velocity distribution. (See also: Regarding...) Figure 2AAs described, the central region 425 (or active orbital region or aperture) is defined where the main mode or basic mode is generally expected and designed to propagate perpendicular to the finger 426.

[0067] In one aspect, a barrier region 429 (e.g., a gap region) is defined outside a central region 427, comprising the area between a first busbar 422 and fingers 426a connected to a relative second busbar 424. More specifically, the barrier region 429 comprises a first barrier region 429a and a second barrier region 429b. The first barrier region 429a is defined between the first busbar 422 and the unconnected ends of a first set of fingers 426a connected to the second busbar 424. The second barrier region 429b is defined between the second busbar 424 and the unconnected ends of a second set of fingers 426b connected to the first busbar 422. The barrier region 429 may sometimes correspond to or be referred to as a lateral gap, which is included in an IDT to separate metal structures with different potentials (i.e., individual fingers connected to a relative busbar, where the busbars have different potentials).

[0068] To adjust the lateral velocity distribution, the number of fingers per wave length within barrier region 429 (e.g., one finger instead of two fingers as illustrated in central region 425) and the distance or size of barrier region 429 (and / or other characteristics within barrier region 429) are chosen such that higher, particularly higher, sound wave velocities exist than in central region 425. Figure 440 to the right of electrode structure 404 illustrates the relative velocities of each region of electrode structure 404, where the y-axis represents the different regions of electrode structure 404 and is aligned with the direction of extension of the fingers 426. As illustrated by line 450 (see dashed section), the sound velocity along the x-axis is higher in barrier region 429 than in central region 425 (e.g., active track). Generally, since sound waves tend to propagate more easily where velocities are lower, a relatively higher wave velocity can be an obstacle to sound waves. The distance / width of the barrier region 429 (e.g., in some aspects, at least 2 micrometers (µm) to 3 µm to adequately separate metallic structures with different potentials). In some aspects, the width of the barrier region 429 can be as small as 200 nanometers (nm). In other aspects, the width of the barrier region 429 can be as large as 8 µm to 10 µm. In still other aspects, larger widths can be used, particularly for low-frequency band or HQ-TCF implementations. In some such aspects, the width 429 can be, for example, approximately 15 µm to 20 µm. In various such aspects, the width is designed to provide sufficient barrier to limit or prevent acoustic wave coupling to the external region.

[0069] In addition to barrier region 429, an additional region, referred to as trap region 427, is provided at any outer boundary (e.g., defined at each end) of the central region 425 where the fingers 426 overlap. Specifically, a first trap region 427a is located or positioned at a first end (e.g., a boundary) toward the central region 425 (e.g., an active region) and between the first barrier region 429a and the central region 425 (e.g., in the region of the end of the fingers 426 toward the first set of fingers 426a connected to the second busbar 424, wherein this region is away from the second busbar 424). A second trap region 427b is located or positioned at a second end (opposite to the first end) toward the central region 425 and between the second barrier region 429b and the central region 425 (e.g., in the region of the end of the fingers 426b toward the second set of fingers 426b connected to the first busbar 422, wherein this region is away from the first busbar 422). The trap region 427 may correspond to the outer edge or outer region of the central region 425. Structural characteristics in the trap region 427, different from those in the central region 425, are provided to create a region of the electroacoustic device aligned with the trap region 427, which has a reduced sound wave velocity, particularly lower than that in the central region 425. Such structural characteristics may include widening the electrode fingers 426 in the trap region 427 or increasing the height of the electrode fingers 426 in the trap region 427, but many specific implementations are possible. Generally, sound waves may tend to propagate more easily at lower velocities. Thus, the trap region 427 with a lower sound wave velocity provides a way to shape the lateral amplitude distribution of the fundamental acoustic wave mode.

[0070] As a result of the design and selection of the sizes of the barrier region 429, the trap region 427, and the central region 425, the fundamental acoustic mode amplitude in the lateral direction (e.g., in the direction of the finger 426) can follow a rectangular distribution, as indicated by line 444 in Figure 440. The rectangular distribution resulting from the different acoustic velocities in the different regions corresponds to the modes in which undesired lateral modes are suppressed. Line 442 in Figure 440 corresponds to the fundamental mode amplitude in the lateral direction when there is no trap region that could lead to undesired lateral modes. Line 446 in Figure 440 corresponds to the fundamental mode amplitude in the lateral direction when the trap region 427 is not deep enough (e.g., the acoustic waves are not sufficiently slowed down in this region). Despite the improvement, undesired lateral modes may continue to affect performance. Line 448 in Figure 440 corresponds to the fundamental mode amplitude in the lateral direction when the trap region 427 is too deep. This can also lead to undesired lateral acoustic modes. By adjusting the characteristics of the barrier region 429 and the well region 427, the amplitude of the fundamental mode in the lateral direction can be adjusted to conform to the rectangular distribution indicated by line 444, and the lateral mode can be effectively suppressed. The technique used to provide the barrier region 429 and the well region 427 in such a configuration is sometimes referred to as the piston mode.

[0071] Figure 5A and Figure 5B These are illustrations of examples of electrode structures 504a and 504b, as shown in the reference. Figure 4 Examples of different specific implementations of the defined trap regions 527-1 and 527-2. Barrier region 529 is shown, but not specifically illustrated or drawn to scale. Instead, electrode structures 504a and 504b are provided to illustrate trap region 527-1 ( Figure 5A ) and 527-2 ( Figure 5B The specific implementation of ). For example, in Figure 5A In electrode structure 504a, the trap region 527-1 is illustrated as a portion 509 of electrode structure 504a having an increased thickness relative to other portions of the active region. A side view along cross-section 531 is shown on the right. The increased height can result in a slower acoustic velocity in the trap region 527-1. In another specific embodiment, such as Figure 5B As illustrated by electrode structure 504b, the electrode structure 504b within the trap region 527-2 has a wider width compared to the active region. This wider width can result in a slower sound velocity in the trap region 527-2. In some specific embodiments, the trap region 527-2 may have both a wider width and an increased height (e.g., thickness) compared to the active region, such as... Figure 5A As illustrated, any techniques described herein with respect to well region 427-2 can be combined. In other specific embodiments, other materials (e.g., a dielectric material layer) may be positioned in well region 427. Figure 4Above, to reduce the sound velocity in the trap region 427 (e.g., or other types of mass load). Additionally, one or more trimming operations may adjust the structural effects in the respective regions, such that the relative sound velocity in the trap region 427 is reduced relative to the central region 425. Other specific implementations using different techniques may also be employed, such that the structural characteristics in the trap region 427 are adjusted and differ from those in the central region 425, resulting in a reduced sound velocity in the trap region 427.

[0072] Some techniques for addressing these problems in electroacoustic devices may be difficult to implement for higher metallization ratios and higher metal heights (and due to other manufacturing difficulties of such solutions) and may increase ohmic losses. In some implementations, the metallization ratio can be between 0.45 and 0.7. The aspects described herein can be achieved with such metallization ratios. In some implementations, lower metallization ratios (which can be below 0.55 as described herein) can be achieved with fewer of the difficulties described above. For example, in some aspects, points on weighted segments or segment electrode fingers formed with increased width may be more difficult to manufacture with high-frequency components and / or high metallization ratios. Additionally, as referenced... Figure 4 The described barrier region 429 (e.g., including one stripping wave length) can result in concavity slowness in certain configurations, such as when using the references above. Figure 3A When describing the lithium tantalate-based device.

[0073] Figure 6 This is an example of a wireless communication device 600 including an electroacoustic resonator 620, as described herein. The wireless communication device 600 can use various filter elements, including one or more electroacoustic resonators 620, to achieve signal characteristics that meet the objectives of a given communication system. As described above, the transmit and receive paths of such a wireless communication device may include multiple signal (e.g., transmit and receive) path elements, exemplified as including an electroacoustic resonator 620 with harmonic suppression structures, and an additional signal path element 610. The additional signal path element 610 may include a low-noise amplifier (LNA), a mixer, a transmit line, filter elements including various SAW resonators, BAW resonators, and other elements. Under high power loads, SAWs may transmit harmonic signals that can follow parasitic paths through the wireless communication device 600, which may interfere with the signal in the additional signal path element 610. Such high power loads may occur particularly at the tuning filter between the amplifier and the transmit antenna in the transmit path after signal amplification.

[0074] Electroacoustic resonator 620 includes both electrode finger gap reflector 630 and wave-shaped electrode fingers. As discussed above and below, the electroacoustic resonator includes electrode fingers. Electrode finger gap reflector 630 includes metallization lines perpendicular to the electrode fingers. Electrode fingers 640 with tip modification refers to the tip shape at the ends of the electrode fingers, these tip shapes being configured to reduce harmonics and thereby improve device operation according to the aspects described herein. Such aspects may include tip regions with reduced-size shapes compared to the main portion of the electrode, and differences in the tip pattern of the electrode compared to the tip of a stub electrode as described below. The combination of electrode finger gap reflector 630 and electrode fingers 640 with tip modification can result in significantly improved harmonic suppression compared to each suppression structure without either one. The following discusses… Figure 11 Details of such performance improvements in the device are illustrated below. The described structures and techniques are applicable to a variety of different types of electroacoustic devices (e.g., BAW devices), but include specific advantages for thin-film SAW electroacoustic devices and thin-film electroacoustic devices using lithium tantalate.

[0075] Figures 8A to 8B and Figures 9A to 9D Details of modifications to the tips of the electrode fingers according to the aspects described herein are illustrated. For clarity, these figures do not include details of gap reflectors that may be used at the base end of the electrode fingers (e.g., the end coupled to the busbar). Figure 7A and Figure 7B This illustrates aspects of a gap reflector that can be integrated with the tip modifications described in further detail below.

[0076] Figure 7A This is an indication of an electroacoustic resonator 700. Similar to the resonator described above, the electroacoustic resonator 700 includes first electrode fingers 710 interleaved with adjacent second electrode fingers 712 to form a track 730. The track 730 is used to filter signals using electroacoustic resonance, as described above. As described above, transverse waves within the electroacoustic resonator 700 can propagate through both the signal path including the electroacoustic resonator 700 and the signal path including the electroacoustic resonator 700. To suppress such transverse waves, the electroacoustic resonator 700 includes suppression structures in the form of gap reflectors 720 and 722. Gap reflectors 720 and 722 can limit a trap between the ends of electrode fingers extending from opposite busbars and are operable to attenuate such transverse waves within the trap.

[0077] Figure 7B This is a representation of region 701 of an electroacoustic resonator 700 based on various aspects of the exemplary harmonic suppression structure described herein. Figure 7B Area 701 is Figure 7AAn enlarged view of region 701. Region 701 includes portions of gap reflector 720, first electrode finger 710, and second electrode finger 712. The portion of second electrode finger 712 shown in region 701 includes associated electrode finger tips 713, which may be modified according to aspects described herein for harmonic suppression. Additional details of such modifications are further described below. Gap reflectors are not shown in the following description, but in any respect, gap reflectors such as gap reflector 720 may be present at the electrode finger tips (e.g., electrode finger tips 713) and opposite busbars ( Figure 7A and Figure 7B Between (not shown in the diagram). Similarly, a gap reflector may be present at the first segment or base segment of the electrode finger near the bus connection, such as at the location of the gap reflector 720 positioned together with the illustrated base segment of the first electrode finger 710, which is coupled to the bus ( Figure 7A and Figure 7B (Not shown in the image) near the location.

[0078] Gap reflectors (e.g., gap reflectors 720 and 722) extend in a direction different from the extension direction of the fingers (e.g., perpendicular or at an angle). In some aspects, gap reflectors 720 and 722 may be substantially parallel to the busbar of the device and perpendicular to the electrode fingers of the fill track 730, wherein gap reflectors 720 and 722 are configured to attenuate signals outside track 730 as described above. Gap reflectors 720 and 722 are positioned between the busbar and the tips of the electrode fingers extending from the opposite busbar.

[0079] Figure 8A This is a representation of an electroacoustic resonator 800 based on various aspects of the harmonic suppression structure described herein. Figure 8A Two staggered electrode fingers are illustrated, shown as a first electrode finger 810 coupled to a first bus 860 and a second electrode finger 812 coupled to a second bus 862. Based on the details provided above, the electroacoustic resonator 800 will include additional electrode fingers, but the two illustrated electrode fingers are shown to provide detail of the aspects described herein.

[0080] As shown, the first electrode finger 810 has a first end portion 832 coupled to a first busbar 860 and an electrode tip 834 positioned away from the first busbar 860 in a direction substantially perpendicular to the first busbar 860. The first electrode finger 810 is further composed of a first segment 842, a piston segment 844, and a tip segment 846. The first segment 842 may include a base piston segment 845. The piston segment 844 of the first electrode finger 810 may be aligned with the base piston segment of a second electrode finger, and the base piston segment 845 may be aligned with the piston segment of the second electrode finger to form a trap region (e.g., similar to trap regions 427a and 427b). Furthermore, in some aspects, additional apodization may be applied. In such aspects, once apodization is applied over a piston-pattern design, the alignment of the trap regions no longer exists.

[0081] As indicated above, the segment between such a trap region and the associated busbar may include gap reflectors (e.g., gap reflectors 720 and 722). For simplicity, such gap reflectors are... Figures 8A to 8B and Figures 9A to 9D Not illustrated. Additionally, as shown in the figure, piston segment 844 is shown to have a width greater than that of the first segment 892. In other respects, the piston segment can be created by increasing the material thickness, by loading dielectric mass onto piston segment 844, or by other such structures.

[0082] exist Figure 8A In the electroacoustic resonator 800, a first segment 842 extends from a first end 832 to an interface with a first piston segment 844. The piston segment 844 extends from the first piston segment interface to an interface with a second piston segment 846, and the tip segment 846 extends from the second piston segment interface with the piston segment 844 in a direction perpendicular to the generatrix to the electrode tip 834. The tip segment 846 may have a width smaller than both the piston segment 844 and the center segment. Additionally, in various aspects, the second piston segment interface 884 of a particular finger may be associated with a change in width or geometry between the structure of the tip segment 846 and the piston segment 884.

[0083] Figure 8B This is a representation of an electroacoustic resonator 800 based on various aspects of the harmonic suppression structure described in this article. As shown in the figure... Figure 8B A closer view with additional details, including the electroacoustic resonator 800. Besides showing the first segment 842, piston segment 844, tip segment 846, and electrode tip 834, Figure 8B It also includes labels for the width of the first piston segment interface 882, the second piston segment interface 884, the width of the first segment 892, and the width of the tip segment 896.

[0084] As indicated above and in Figure 8BFurther detailed, in the electroacoustic resonator 800, a first segment 842 extends from a first end 832 to a first piston segment 844 interface 882. The piston segment 844 extends from the first piston segment interface 882 to a second piston segment interface 884 with a tip segment 846, and the tip segment 846 extends from the second piston segment interface 884 with the piston segment 844 to an electrode tip 834 in a direction perpendicular to the generatrices 860 and 862. According to some aspects of harmonic suppression described herein, the width of the tip segment 896 at its widest position is narrower than the width of the first segment 892 at its narrowest position.

[0085] The illustrated embodiment of resonator 800 includes a small rectangular stub for tip segment 846. In other respects, other shapes may be used for tip segment 846, provided that the width of tip segment 896 is narrower than the width of first segment 892. For example, triangular geometry, cusp geometry, or other such geometries may be used, wherein the width of the fingers at the second piston segment interface 884 or at another portion of tip segment 846 does not exceed the widest width of first segment 842.

[0086] Figure 9A This is an representation of an electroacoustic resonator 900 according to various aspects of the exemplary harmonic suppression structure described herein. In some aspects, the electroacoustic resonator may include electrode fingers aligned with stubular electrode fingers positioned on the same shared line as the electrode fingers, such that the tips of the electrode fingers face the tips of the stubular fingers rather than opposing side busbars (e.g., Figure 8A and Figure 8B ) or gap reflector (e.g., Figure 7A and Figure 7B In some specific implementations, such stubular electrode fingers can be further used to tune frequency response performance. Figure 9A The electroacoustic resonator 900 includes a first electrode finger 910 and stubular electrode fingers. As in the example above, the electroacoustic resonator 900 may include additional interleaved fingers and stubular fingers that have alternating orientations with adjacent fingers (e.g., the first electrode finger 910 is adjacent to two stubular fingers, and the stubular electrode finger 950 is adjacent to two electrode fingers). For simplicity, such adjacent structures are not shown in the text. Figure 9A As shown in the image.

[0087] The electroacoustic resonator 900 includes a first busbar 960 and a second busbar 962 generally parallel to the first busbar. A first electrode finger 910 is coupled to the first busbar 960 and extends toward the second busbar 962 in a first direction without contacting the second busbar. The first electrode finger 910 also includes a first segment 942 coupled to the first busbar 960 at a first end 932. The first electrode finger 910 also includes a second segment 944 having a finger tip 934 with a first shape.

[0088] The electroacoustic resonator 900 additionally includes a first stub electrode finger 950 coupled to a second busbar 962 and extending toward the finger tip 934 of the first electrode finger 910 in a second direction opposite to the first direction. The first stub electrode finger 950 has a second end portion 954 and a first end portion 952 coupled to the second busbar 962. The second end portion 954 faces the tip 934 of the second segment 944 of the first electrode finger. According to the harmonic suppression aspect described herein, the second end portion 954 of the stub electrode finger 950 terminates in a second shape different from the first shape of the tip 934. In some aspects, the second end portion 954 has a stub tip with a shape different from the shape of the other portions of the stub electrode finger 950. In other respects, the tip of the stub (e.g., the end of the second end 954 of the stub electrode finger 950) may be a flat rectangular end of a rectangular stub finger, provided that the end is a different shape from the tip 934 of the second segment 944 of the first electrode finger 910.

[0089] Figure 9B This is a representation of an electroacoustic resonator 900 based on various aspects of the harmonic suppression structure illustrated herein. Except for the stubbed electrode fingers, the first electrode finger 910, the first end 952 and the second end 954 of the stubbed electrode finger, and the first segment 942, the second segment 944, and the tip 934 of the first electrode finger, which are shown... Figure 9B The different shapes of the adjacent electrode fingers and the tip 934 of the first electrode finger 910 are also shown.

[0090] As illustrated, the alternating electrode fingers, including the first electrode finger 910, include a first shape 935 at the electrode tip 934. Similarly, the stub electrode fingers 950 and the alternating stubs include a second shape 955 at the second end 954. A similar configuration will exist on the other side of the electroacoustic resonator 900, including electrodes adjacent to the first electrode finger 910 (only the base segment is in...). Figure 9B (as shown in the diagram) and stubby electrode fingers and shaped tips for alternating fingers (e.g., every other electrode finger). Figure 9BIn the first shape 935, the first shape is a triangle and the second shape 955 is a flat rectangle.

[0091] Similar to Figure 9B , Figure 9C and Figure 9D This is a representation of an electroacoustic resonator 900 based on various aspects of the illustrative harmonic suppression structure described herein. Specifically, Figure 9C An embodiment of the first shape 935 is illustrated, consisting of two curves intersecting at a point on the tip 934. Figure 9D An embodiment of the first shape 935 is illustrated, consisting of multiple rectangular stub shapes. Other combinations of shapes may be used in other aspects. For example, in one embodiment, Figure 9B The first shape illustrated can be used as Figure 9C In a specific implementation, a second shape is used, wherein a triangle shape is used for the second shape 955 and a cusp shape is used for the first shape 935. In other aspects, other shapes may be used. For example, in one aspect, a rectangular stub resembling one of four rectangular stubs may be used for the first shape 935, and a rectangular stub offset in any direction may be used for the second shape. Similarly, in one aspect, the first shape 935 may include a single stub (e.g., resembling...). Figure 8A The illustrated shape), and the second shape 935 may include two or more short stubs separated from each other by gaps (e.g., similar to the shape shown). Figure 9D (Specific implementation of the four short stubs).

[0092] Based on the details provided herein, any such aspect, with different finger and stub shapes, can be used in conjunction with a piston segment for harmonic suppression (e.g., where the first electrode finger 910 also includes a first piston segment between the first segment 942 and the second segment 944 near the finger tip 934). Such piston segments can be manufactured in various ways, including using wider electrodes in the piston segment (e.g., as...). Figure 8A and Figure 8B (as illustrated), using a greater metal thickness in the piston section, using additional materials (e.g., dielectric layers) on the metallization layer in the piston section, or any other such mechanism for modifying the metallization layer in the piston section.

[0093] This electroacoustic resonator can then be integrated into a communication device. For example, in some aspects, the electroacoustic resonator 900 or any other such electroacoustic resonator can be implemented as part of the transmission path of a wireless communication device. In one aspect, such a wireless communication device also includes an antenna, an amplifier, a first antenna path coupled between a first bus and the antenna, and a first transmission path coupled from the output of the amplifier to a second bus. (The following...) Figure 10Another specific implementation example is illustrated. It will be apparent that other specific implementations are possible within the scope of the aspects described herein.

[0094] The electrode tip modifications for electroacoustic resonators illustrated above suppress harmonics by disrupting the transverse field that generates the dominant nonlinear signal and by disrupting the cascading of such nonlinearity through the device (e.g., the enhancement of nonlinearity along a track such as track 730). The aspects described herein modify these regions to reduce second-order nonlinearity and improve device performance. Since the device shape is modified at the electrode tips rather than by changing the size or configuration of the electrode fingers, such improvements can be provided with little or no increase in device area.

[0095] Figure 10 This is a representation of a wireless communication device 1000 including an electroacoustic resonator for harmonic suppression, according to various aspects described herein. The wireless communication device 1000 includes a transmitting path 1001 and a receiving path 1002. As described above, after signal power amplification, harmonics from the electroacoustic resonator can be particularly detrimental to device performance near the output of the transmitting path 1001, where the power through the electroacoustic resonator, such as resonator 1011, may be relatively high. In high-power operation through resonator 1011, harmonics from resonator 1011 can travel via parasitic paths 1014, 1025, and 1024 to other electroacoustic resonators (such as resonator 1010) in different paths, as well as resonators 1020 and 1021 in the receiving path 1002. Interference from harmonics in such paths can interfere not only with the electroacoustic signal in SAW resonators but also with the electroacoustic signal in other resonators, such as BAW resonators. Modifications to the electrode finger tips according to the aspects described herein, as described above, can suppress second harmonics in a device, thereby suppressing noise from such sources within the design. Electroacoustic resonators with modified electrode tips for harmonic suppression according to the aspects described herein can improve device operation, particularly in the context of cascaded resonators that lead to parasitic harmonics and degraded performance in the RF front-end modules of communication devices.

[0096] Figure 11 Figure 1100 illustrates improvements in the performance of wireless communication devices, including electroacoustic resonators with harmonic suppression, based on the various aspects described herein. Figure 1100 illustrates an example plotting frequency on the horizontal axis against second harmonic power on the vertical axis. Line 1110 shows a curve for an electroacoustic resonator without improvements according to the various aspects described herein. Line 1120 shows a curve for an electroacoustic resonator with similar... Figure 8AThe illustrated curves show the modified tips of the electroacoustic resonator. Line 1110 shows the additional power in the second harmonic across the illustrated spectrum without the illustrated tip modifications according to the aspects described herein. In contrast, line 1120 shows the significant suppression of the second harmonic power associated with the tip modifications according to the various aspects described herein. Figure 1100 is an example modeled using one of the aspects described herein. Different aspects can be used in different device designs depending on the various manufacturing and performance goals and constraints implemented for a particular device.

[0097] The above text Figures 8A to 8B and Figures 9A to 9D The shapes illustrated in the diagram depict clear lines. Electrode fingers can be fabricated at or near the limits of certain manufacturing processes, resulting in variations due to the manufacturing process. In some aspects, the illustrated shapes can be associated with the mask shapes used to fabricate the metallization layers of interdigital transducers. For example, in some aspects, the tip shape can be fabricated using a rectangular stub shape on the tip region of the mask, wherein the resulting shape of the metallization layer is shaped by the rectangular mask in the tip region, but is not rectangular due to variations in the manufacturing process. In some aspects, optical proximity correction can be used to pre-distort the mask during its fabrication, and more accurate wafer results can be generated for small geometries, such as a tip segment 846 having a width 896 configured to be at the limits of a given manufacturing process.

[0098] Figure 12 A method 1200 for manufacturing a resonator according to various aspects described herein is illustrated. In some aspects, method 1200 is implemented by a system including a memory and one or more processors configured to perform operations indicated by method 1200. In some aspects, method 1200 is implemented via a non-transitory computer-readable storage medium including instructions that, when executed by one or more processors of the device, cause the device to perform the operations of method 1200.

[0099] like Figure 12 As illustrated, method 1200 includes block 1202, which describes the fabrication of a metallization layer mask, the metallization layer mask including: a first electrode finger shape extending in a first direction and having a second end and a first end coupled to a first busbar segment, wherein the second end includes a finger tip having a first shape; and a first stub electrode finger shape extending in a second direction opposite to the first direction toward the finger tip of the first electrode finger shape, wherein the first stub electrode finger shape includes a second end and a first end coupled to a second busbar segment, and wherein the second end includes a stub tip having a second shape different from the first shape.

[0100] Method 1200 also includes box 1204, which describes the use of a metallization layer mask to fabricate the metallization layer of an electroacoustic resonator.

[0101] As detailed above, in some respects, method 1200 can be implemented using predistortion to create a shape using the shape of the predistortion in the mask, thereby creating the desired shape in the metallization layer.

[0102] Additional illustrative aspects of this disclosure include:

[0103] Aspect 1. An electroacoustic resonator, comprising: a first busbar; a second busbar; a first electrode finger coupled to the first busbar and extending toward the second busbar in a first direction without contacting the second busbar, wherein the first electrode finger includes a finger tip having a first shape; and a first stub electrode finger coupled to the second busbar and extending toward the finger tip of the first electrode finger in a second direction opposite to the first direction, wherein the first stub electrode finger includes a second end portion and a first end portion coupled to the second busbar, and wherein the second end portion includes a stub tip having a second shape different from the first shape.

[0104] Aspect 2. The electroacoustic resonator according to aspect 1, wherein the first shape is a rectangular shape.

[0105] Aspect 3. The electroacoustic resonator according to aspect 2, wherein the first shape comprises a plurality of rectangular stub shapes, the plurality of rectangular stub shapes comprising the rectangular shape.

[0106] Aspect 4. The electroacoustic resonator according to any one of Aspects 1 to 3, wherein the first shape is a triangular shape.

[0107] Aspect 5. The electroacoustic resonator according to any one of Aspects 1 to 4, wherein the first shape comprises a curve intersecting at a point at the tip of the finger.

[0108] Aspect 6. The electroacoustic resonator according to any one of Aspects 1 to 5, wherein the first electrode finger further comprises a first piston segment adjacent to the tip of the finger, located between a first segment and a second segment of the first electrode finger.

[0109] Aspect 7. The electroacoustic resonator according to aspect 6, wherein the first piston section includes a region with increased thickness compared to the thickness of the first section of the first electrode finger.

[0110] Aspect 8. The electroacoustic resonator according to aspect 6, wherein the first piston segment includes a region with an additional width compared to the width of the first segment of the first electrode finger.

[0111] Aspect 9. The electroacoustic resonator according to any one of Aspects 1 to 8 further comprises: a first gap reflector, the first gap reflector being parallel to the first busbar and extending in a direction different from the first electrode finger, wherein the first gap reflector intersects the first electrode finger in a gap between the first busbar and the finger extending toward the first busbar.

[0112] Aspect 10. The electroacoustic resonator according to aspect 9 further includes: a second gap reflector extending in a direction different from the first stub electrode finger, wherein the second gap reflector intersects the first stub electrode finger in a gap between the second busbar and the first electrode finger.

[0113] Aspect 11. An electroacoustic resonator according to any one of Aspects 1 to 10, wherein the electroacoustic resonator is part of the transmission or reception path of a wireless communication device, and wherein the wireless communication device further comprises: an antenna; and an amplifier.

[0114] Aspect 12. An electroacoustic resonator, comprising: an electrode finger including a first end coupled to a busbar and an electrode tip positioned away from the busbar in a direction substantially perpendicular to the busbar, the electrode finger further comprising a first segment, a piston segment, and a tip segment; wherein the first segment extends from the first end to a first piston segment interface; wherein the piston segment extends from the first piston segment interface to a second piston segment interface; and wherein the tip segment extends from the second piston segment interface to the electrode tip in a direction perpendicular to the busbar, wherein the width of the tip segment at its widest position is narrower than the width of the first segment at its narrowest position.

[0115] Aspect 13. The electroacoustic resonator according to aspect 12, wherein the tip segment has a rectangular shape.

[0116] Aspect 14. The electroacoustic resonator according to aspect 13, wherein the tip segment includes a plurality of rectangular stub shapes, the plurality of rectangular stub shapes including the rectangular shape.

[0117] Aspect 15. The electroacoustic resonator according to aspect 12, wherein the tip segment has a triangular shape.

[0118] Aspect 16. The electroacoustic resonator according to aspect 12, wherein the tip segment includes a curve intersecting at a point at the tip of the finger.

[0119] Aspect 17. The electroacoustic resonator according to any one of Aspects 12 to 16 further comprises: a gap reflector, the gap reflector being parallel to the busbar and extending in a direction different from the electrode finger, wherein the gap reflector intersects the first electrode finger in a gap between the busbar and the electrode finger extending toward the busbar without contacting the busbar.

[0120] Aspect 18. The electroacoustic resonator according to any one of Aspects 12 to 17, wherein the electroacoustic resonator is part of the transmission or reception path of a wireless communication device, and wherein the wireless communication device further comprises: an antenna; and an amplifier.

[0121] Aspect 19. A method of manufacturing an electroacoustic resonator, the method comprising: manufacturing a metallization layer mask, the metallization layer mask comprising: a first electrode finger shape extending in a first direction and having a second end and a first end coupled to a first busbar segment, wherein the second end includes a finger tip having a first shape; and a first stub electrode finger shape extending in a second direction opposite to the first direction toward the finger tip of the first electrode finger shape, wherein the first stub electrode finger shape includes a second end and a first end coupled to a second busbar segment, and wherein the second end includes a stub tip having a second shape different from the first shape; and manufacturing a metallization layer of the electroacoustic resonator using the metallization layer mask.

[0122] Aspect 20. The method according to aspect 19, wherein the metallization layer mask includes a pre-distortion pattern for generating the second shape of the second end.

[0123] Aspect 21. An electroacoustic resonator, comprising: a first busbar; a second busbar, the second busbar being generally parallel to the first busbar; a first plurality of electrode fingers, the first plurality of electrode fingers being coupled to the first busbar and extending toward the second busbar in a first direction without contacting the second busbar, each of the first plurality of electrode fingers having a second end and a first end coupled to the first busbar, wherein the second end includes a finger tip; a second plurality of electrode fingers, the second plurality of electrode fingers being coupled to the second busbar and extending toward the first busbar in a second direction without contacting the first busbar, each of the second plurality of electrode fingers having a second end and a first end coupled to the second busbar, wherein the first plurality of electrode fingers and the first plurality of electrode fingers are coupled to the first busbar and extend ... Two or more electrode fingers are interleaved; and a first or more stub electrode fingers, the first or more stub electrode fingers being coupled to the second busbar and extending toward the first busbar in the second direction, each of the first or more stub electrode fingers having a second end and a first end coupled to the second busbar, each of the first or more stub electrode fingers sharing a line with a corresponding electrode finger in the first or more electrode fingers and having a stub tip facing the finger tip of the corresponding electrode finger in the first or more electrode fingers, wherein the shape of each stub tip in the first or more stub electrode fingers is different from the shape of the finger tip of the corresponding electrode finger in the first or more electrode fingers.

[0124] Aspect 22. A method of manufacturing an electroacoustic resonator, the method comprising: manufacturing a metallization layer mask, the metallization layer mask including: an electrode finger shape including a first end coupled to a bus segment and an electrode tip positioned away from the bus segment in a direction substantially perpendicular to the bus segment, the electrode finger shape further including a first segment and a tip segment; wherein the width of the tip segment at its widest position is narrower than the width of the first segment at its narrowest position; and manufacturing the metallization layer of the electroacoustic resonator using the metallization layer mask.

[0125] Aspect 23. A method for transmitting or receiving wireless signals using any of the above-described devices.

[0126] Aspect 24. A non-transitory computer-readable medium comprising instructions that, when executed by a wireless communication device, cause the wireless communication device to transmit or receive signals using any of the means or methods described above.

[0127] Aspect 25. An apparatus comprising components for performing any of the operations described above.

[0128] Figure 13 This is a functional block diagram of at least a portion of an example of a simplified wireless transceiver circuit 1300, which may employ a filter with harmonic suppression according to the aspects described above. The transceiver circuit 1300 is configured to receive signals / information (shown as I and Q values) for transmission, which are provided to one or more baseband filters 1312. The filtered output is provided to one or more mixers 1314. The output from the one or more mixers 1314 is provided to a driver amplifier 1316, the output of which is provided to a power amplifier 1318 to generate an amplified signal for transmission. The amplified signal is output to an antenna 1322 through one or more filters 1320 (e.g., a duplexer (if used as a frequency division duplex transceiver) or other filters). The one or more filters 1320 may include any filter circuitry described herein, which may include one or more resonators according to the details described above. The antenna 1322 can be used to wirelessly transmit and receive data. Transceiver circuitry 1300 includes the following receive path: before the signal is further processed (e.g., provided to an analog-to-digital converter and then demodulated or otherwise processed in the digital domain), it passes through one or more filters 1320 to be supplied to a low-noise amplifier (LNA) 1324 and an additional filter 1326, and then down-converts from the receive frequency to a baseband frequency via one or more mixer circuits 1328. Separate filters for the receive circuitry may be available, implemented using any of the filter circuitry described herein (e.g., the receive circuitry may have a separate antenna or a separate receive filter).

[0129] Figure 14 This is a diagram of an environment 1400 including electronic device 1402, which includes wireless transceiver 1496, such as Figure 13 The transceiver circuit 1300. In environment 1400, electronic device 1402 communicates with base station 1404 via wireless link 1406. As shown, electronic device 1402 is depicted as a smartphone. However, electronic device 1402 can be implemented as any suitable computing device or other electronic device, such as a cellular base station, broadband router, access point, cellular or mobile phone, gaming device, navigation device, media device, laptop computer, desktop computer, tablet computer, server computer, network attached storage (NAS) device, smart appliance, vehicle-based communication system, Internet of Things (IoT) device, sensor or security device, asset tracker, etc.

[0130] Base station 1404 communicates with electronic device 1402 via wireless link 1406, which can be implemented as any suitable type of wireless link. Although depicted as a base station tower of a cellular radio network, base station 1404 can represent or be implemented as another device, such as a satellite, terrestrial broadcast tower, access point, peer device, mesh network node, fiber optic line, or another electronic device generally as described above. Therefore, electronic device 1402 can communicate with base station 1404 or another device via wired connection, wireless connection, or a combination thereof. Wireless link 1406 can include a downlink transmitting data or control information from base station 1404 to electronic device 1402, and an uplink transmitting other data or control information from electronic device 1402 to base station 1404. Wireless link 1406 can use any suitable communication protocol or standard, such as 3GPP LTE, 3GPP NR 5G, IEEE 802.11, IEEE 802.16, Bluetooth, etc. ™ (etc.) to achieve this.

[0131] Electronic device 1402 includes processor 1480 and memory 1482. Memory 1482 may be part of or form part of a computer-readable storage medium. Processor 1480 may include any type of processor, such as an application processor or a multi-core processor, configured to execute processor-executable instructions (e.g., code) stored in memory 1482. Memory 1482 may include any suitable type of data storage medium, such as volatile memory (e.g., random access memory (RAM)), non-volatile memory (e.g., flash memory), optical media, magnetic media (e.g., magnetic disk or magnetic tape), etc. In the context of this disclosure, memory 1482 is implemented to store instructions 1484, data 1486, and other information of electronic device 1402, and therefore, when configured as a computer-readable storage medium or part thereof, memory 1482 does not include transient propagation signals or carrier waves.

[0132] Electronic device 1402 may also include input / output port 1490. I / O port 1490 enables data exchange or interaction with other devices, networks, or users, or between components of the device.

[0133] Electronic device 1402 may also include a signal processor (SP) 1492 (e.g., such as a digital signal processor (DSP)). The signal processor 1492 may function similarly to a processor and may be able to execute instructions and / or process information in conjunction with memory 1482.

[0134] For communication purposes, electronic device 1402 also includes a modem 1494, a wireless transceiver 1496, and an antenna (not shown). The wireless transceiver 1496 uses radio frequency (RF) wireless signals to provide connectivity to a given network and other electronic devices connected to those networks, and may include... Figure 13 The transceiver circuit 1300. The wireless transceiver 1496 can facilitate communication over any suitable type of wireless network, such as wireless local area network (LAN) (WLAN), peer-to-peer (P2P) network, mesh network, cellular network, wireless wide area network (WWAN), navigation network (e.g., North American Global Positioning System (GPS) or another Global Navigation Satellite System (GNSS)) and / or wireless personal area network (WPAN).

[0135] The various operations of the methods described above can be performed by any suitable component capable of performing the corresponding functions. This component may include various hardware and / or software components and / or modules, including but not limited to circuits, application-specific integrated circuits (ASICs), or processors. As part of such operations, the methods described above may also include blocks for performing any additional functions described for a device with harmonic suppression according to the example operations described herein.

[0136] By way of example, the elements described herein, or any portion thereof, or any combination thereof, may be implemented as a “processing system” including one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, system-on-a-chip (SoCs), baseband processors, field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gate logic, discrete hardware circuitry, and other suitable hardware configured to perform the various functionalities described throughout this disclosure. One or more processors in the processing system can execute software. Whether referred to as software, firmware, middleware, microcode, hardware description language, or other names, software should be broadly interpreted as meaning instructions, instruction sets, code, code segments, program code, programs, subroutines, software components, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc.

[0137] Therefore, in one or more example embodiments, the described function or circuit block can be implemented in hardware, software, or any combination thereof. If implemented in software, the function can be stored or encoded as one or more instructions or code on a computer-readable medium. A computer-readable medium includes a computer storage medium. The storage medium can be any available medium accessible by a computer. By way of example, and not limitation, such a computer-readable medium can include random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), optical disc storage devices, magnetic disk storage devices, other magnetic storage devices, combinations of computer-readable media of the foregoing types, or any other medium capable of storing computer-executable code in the form of computer-accessible instructions or data structures. In some aspects, the components described as circuits can be implemented in hardware, software, or any combination thereof.

[0138] Generally speaking, when the operations illustrated in the accompanying drawings exist, those operations may have corresponding parts and functional components with similar numbers.

[0139] As used herein, the term "determine" encompasses a wide variety of actions. For example, "determine" can include calculation, operation, processing, deduction, investigation, lookup (e.g., searching in a table, database, or other data structure), assertion, etc. Furthermore, "determine" can include receiving (e.g., receiving information), accessing (e.g., accessing data in memory), etc. Additionally, "determine" can include parsing, selecting, picking, building, etc.

[0140] As used in this article, the phrase “at least one of” in a list of items refers to any combination of those items, including a single member. As an example, “at least one of a, b, or c” is intended to cover: a, b, c, ab, ac, bc, and abc, as well as any combination with multiple identical elements (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbb, cc, and ccc, or any other ordering of a, b, and c).

[0141] The methods disclosed herein include one or more steps or actions for implementing the described methods. The steps and / or actions of the methods may be interchanged without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of a particular step and / or action may be modified without departing from the scope of the claims.

[0142] It should be understood that the claims are not limited to the precise configurations and components illustrated above. Various modifications, alterations, and variations may be made to the arrangement, operation, and details of the methods and apparatus described above without departing from the scope of the claims.

Claims

1. An electroacoustic resonator, comprising: First busbar; Second busbar; A first electrode finger is coupled to the first busbar and extends toward the second busbar in a first direction without contacting the second busbar, wherein the first electrode finger includes a finger tip having a first shape. and A first stub electrode finger is coupled to the second busbar and extends toward the tip of the finger in a second direction opposite to the first direction, wherein the first stub electrode finger includes a second end and a first end coupled to the second busbar, and wherein the second end includes a stub tip having a second shape different from the first shape.

2. The electroacoustic resonator according to claim 1, wherein the first shape is a rectangular shape.

3. The electroacoustic resonator according to claim 2, wherein the first shape comprises a plurality of rectangular stub shapes, and the plurality of rectangular stub shapes include the rectangular shape.

4. The electroacoustic resonator according to claim 1, wherein the first shape is a triangular shape.

5. The electroacoustic resonator of claim 1, wherein the first shape comprises a curve intersecting at a point at the tip of the finger.

6. The electroacoustic resonator of claim 1, wherein the first electrode finger further comprises a first piston segment adjacent to the tip of the finger, located between a first segment and a second segment of the first electrode finger.

7. The electroacoustic resonator of claim 6, wherein the first piston section includes a region with increased thickness compared to the thickness of the first section of the first electrode finger.

8. The electroacoustic resonator of claim 6, wherein the first piston segment includes a region with an increased width compared to the width of the first segment of the first electrode finger.

9. The electroacoustic resonator according to claim 1, further comprising: A first gap reflector, the first gap reflector being parallel to the first generatrix and extending in a direction different from the first electrode finger, wherein the first gap reflector intersects the first electrode finger in the gap between the first generatrix and the finger extending toward the first generatrix.

10. The electroacoustic resonator according to claim 9, further comprising: A second gap reflector extends in a direction different from that of the first stub electrode finger, wherein the second gap reflector intersects the first stub electrode finger in the gap between the second busbar and the first electrode finger.

11. The electroacoustic resonator of claim 1, wherein the electroacoustic resonator is part of the transmit or receive path of a wireless communication device, and wherein the wireless communication device further comprises: antenna; and Amplifier.

12. An electroacoustic resonator, comprising: An electrode finger includes a first end coupled to a busbar and an electrode tip positioned away from the busbar in a direction substantially perpendicular to the busbar; the electrode finger also includes a first segment, a piston segment, and a tip segment. The first segment extends from the first end to the interface of the first piston segment; The piston segment extends from the first piston segment interface to the second piston segment interface; and The tip segment extends from the second piston segment interface to the electrode tip in a direction perpendicular to the generatrix, wherein the width of the tip segment at its widest position is narrower than the width of the first segment at its narrowest position.

13. The electroacoustic resonator of claim 12, wherein the tip segment has a rectangular shape.

14. The electroacoustic resonator of claim 13, wherein the tip segment comprises a plurality of rectangular stub shapes, the plurality of rectangular stub shapes including the rectangular shape.

15. The electroacoustic resonator of claim 12, wherein the tip segment has a triangular shape.

16. The electroacoustic resonator of claim 12, wherein the tip segment includes a curve intersecting at a point at the tip of the finger.

17. The electroacoustic resonator according to claim 12, further comprising: A gap reflector, the gap reflector being parallel to the busbar and extending in a direction different from the electrode fingers, wherein the gap reflector intersects the first electrode finger in the gap between the busbar and the electrode fingers extending toward the busbar without contacting the busbar.

18. The electroacoustic resonator of claim 12, wherein the electroacoustic resonator is part of the transmit or receive path of a wireless communication device, and wherein the wireless communication device further comprises: antenna; and Amplifier.

19. A method for manufacturing an electroacoustic resonator, comprising: Fabricating a metallization layer mask includes: A first electrode finger shape, the first electrode finger shape extending in a first direction and having a second end and a first end coupled to a first busbar segment, wherein the second end includes a finger tip having a first shape; and A first stub electrode finger shape extends toward the finger tip in a second direction opposite to the first direction, wherein the first stub electrode finger shape includes a second end and a first end coupled to a second busbar segment, and wherein the second end includes a stub tip having a second shape different from the first shape; and The metallization layer of the electroacoustic resonator is manufactured using the metallization layer mask.

20. The method of claim 19, wherein the metallization layer mask includes a pre-distortion pattern for generating the second shape of the second end.

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