Piezoelectric antenna, preparation method and electronic device

Abstract

The embodiment of the invention provides a piezoelectric antenna, a preparation method and an electronic device. The piezoelectric antenna comprises a piezoelectric layer, a piezoelectric resonator and an external radiator. The piezoelectric resonator is arranged on the first surface of the piezoelectric layer and comprises a first terminal, a resonance electrode, a second terminal and at least one ground loop, the first terminal is electrically connected with the resonance electrode and is configured to apply alternating voltage generated by an input radio frequency signal to the resonance electrode, the resonance electrode is surrounded by the at least one ground loop, and the second terminal is electrically connected with the resonance electrode. The first terminal is configured to excite the piezoelectric layer to generate acoustic resonance under the action of alternating voltage, the second terminal is electrically connected with the resonance electrode and configured to output current generated by the piezoelectric layer on the resonance electrode, and the external radiator is electrically connected with the second terminal and configured to conduct the current to radiate electromagnetic waves. According to the piezoelectric antenna provided by the embodiment of the invention, the size of the radiation aperture can be expanded to one hundredth to one tenth of the electromagnetic wave wavelength magnitude, the radiation performance is improved, and the actual requirement is met.

Description

Technical Field

[0001] Embodiments of this disclosure relate to a piezoelectric antenna and its fabrication method, as well as an electronic device. Background Technology

[0002] Acoustic-excited antennas utilize the acoustic resonance of an acoustic resonator to replace electromagnetic resonance, achieving effective radiation at scales less than one-hundredth the wavelength of electromagnetic waves, which has significant advantages over traditional electrical antennas of the same size.

[0003] Currently, acoustically excited magnetoelectric antennas operating in the 100 MHz to 1 GHz frequency band operate based on the principle of magnetic moment precession in magnetostrictive thin films. The design and optimization of these antennas typically focus on optimizing piezoelectric / magnetostrictive thin film heterojunctions. However, due to the limited driving ability of thin film materials for magnetic moments, these antennas struggle to achieve strong radiation. Bulk acoustic resonator-excited radiation schemes have high quality factors and relatively strong radiation capabilities, but their complex processes and high fabrication costs make it difficult to achieve high-consistency, large-scale production. In contrast, acoustically mediated piezoelectric antennas only require a piezoelectric resonator to achieve electromagnetic radiation, eliminating the need for a magnetic thin film and simplifying the manufacturing process. Summary of the Invention

[0004] At least one embodiment of this disclosure provides a piezoelectric antenna, including a piezoelectric layer; a piezoelectric resonator disposed on a first surface of the piezoelectric layer, including a first terminal, a resonant electrode, a second terminal, and at least one ground loop, wherein the first terminal is electrically connected to the resonant electrode and is configured to apply an alternating voltage generated by an input radio frequency signal to the resonant electrode, the resonant electrode is surrounded by at least one ground loop and is configured to excite the piezoelectric layer to generate acoustic resonance under the action of the alternating voltage, the second terminal is electrically connected to the resonant electrode and is configured to output a current generated by the piezoelectric layer on the resonant electrode; and an external radiator is electrically connected to the second terminal and is configured to conduct current to radiate electromagnetic waves.

[0005] For example, in at least one embodiment of the present disclosure, a piezoelectric antenna is provided in which the external radiator is separately disposed from the piezoelectric layer, and the external radiator is electrically connected to the second terminal through an encapsulated interconnect.

[0006] For example, at least one embodiment of the present disclosure provides a piezoelectric antenna in which an external radiator is disposed on a first surface of the piezoelectric layer and electrically connected to a second terminal via a metal wiring.

[0007] For example, at least one embodiment of the piezoelectric antenna provided in this disclosure further includes: a reflective grating disposed on a first surface of the piezoelectric layer, on at least one side of the resonant electrode, and configured to reflect acoustic waves excited by the resonant electrode to generate a standing wave signal.

[0008] For example, at least one embodiment of the present disclosure provides a piezoelectric antenna in which a reflective grating is surrounded by at least one ground loop and a resonant electrode.

[0009] For example, at least one embodiment of the piezoelectric antenna provided in this disclosure has an external radiator that is a planar or three-dimensional structure.

[0010] For example, at least one embodiment of the present disclosure provides a piezoelectric antenna in which the size of the external radiator is at least one of the following: less than one percent of the working electromagnetic wavelength, greater than or equal to one percent of the working electromagnetic wavelength and less than or equal to one-tenth of the working electromagnetic wavelength, and greater than one-tenth of the working electromagnetic wavelength, wherein the working electromagnetic wavelength is the wavelength of the electromagnetic wave generated by the piezoelectric antenna.

[0011] For example, at least one embodiment of the present disclosure provides a piezoelectric antenna in which the resonant electrode includes a pair of opposing first interdigital electrodes and second interdigital electrodes, the first interdigital electrodes being electrically connected to the first terminal and the second interdigital electrodes being electrically connected to the second terminal.

[0012] For example, in at least one embodiment of the present disclosure, a piezoelectric antenna is provided, wherein the resonant electrode includes a top electrode and a bottom electrode arranged vertically opposite to each other, and the piezoelectric antenna also includes a suspended piezoelectric film, wherein the top electrode and the bottom electrode are respectively disposed on the two side surfaces of the suspended piezoelectric film.

[0013] For example, in at least one embodiment of the present disclosure, a piezoelectric antenna is provided, wherein the resonant electrode includes a top electrode and a bottom electrode arranged vertically opposite each other, the top electrode and the bottom electrode are respectively disposed on both sides of the piezoelectric layer, and the piezoelectric antenna also includes a reflective layer disposed on the lower surface of the bottom electrode.

[0014] At least one embodiment of this disclosure also provides a piezoelectric antenna including any of the above embodiments.

[0015] At least one embodiment of this disclosure also provides a method for fabricating a piezoelectric antenna, comprising: forming a piezoelectric layer; forming a piezoelectric resonator on a first surface of the piezoelectric layer, wherein the piezoelectric resonator includes a first terminal, a resonant electrode, a second terminal, and at least one ground loop, wherein the first terminal is electrically connected to the resonant electrode and is configured to apply an alternating voltage generated by an input radio frequency signal to the resonant electrode, the resonant electrode is surrounded by at least one ground loop and is configured to excite the piezoelectric layer to generate acoustic resonance under the action of the alternating voltage, the second terminal is electrically connected to the resonant electrode and is configured to output a current generated by the piezoelectric layer on the resonant electrode; and forming an external radiator, wherein the external radiator is electrically connected to the second terminal and is configured to conduct current to radiate electromagnetic waves.

[0016] For example, at least one embodiment of this disclosure provides a method for fabricating a piezoelectric antenna, wherein forming a piezoelectric resonator on a first surface of a piezoelectric layer includes: forming a first photoresist pattern on the first surface of the piezoelectric layer; forming a first metal layer on the first surface of the piezoelectric layer; and stripping the photoresist and the first metal layer on the photoresist to obtain the piezoelectric resonator.

[0017] For example, at least one embodiment of this disclosure provides a method for fabricating a piezoelectric antenna, wherein an external radiator and a piezoelectric layer are fabricated separately, and the method further includes: providing an encapsulation interconnect to electrically connect the external radiator and a second terminal.

[0018] For example, at least one embodiment of this disclosure provides a method for fabricating a piezoelectric antenna, wherein a piezoelectric resonator and an external radiator are integrally fabricated. Forming the piezoelectric resonator and the external radiator on a first surface of the piezoelectric layer includes: forming a second photoresist pattern on the first surface of the piezoelectric layer; forming a second metal layer on the first surface of the piezoelectric layer; and peeling off the photoresist and the second metal layer on the photoresist to obtain the piezoelectric resonator and the external radiator, wherein the external radiator is electrically connected to a second terminal via metal wiring.

[0019] For example, at least one embodiment of the present disclosure provides a method for fabricating a piezoelectric antenna, which further includes: forming a reflective grating on a first surface of the piezoelectric layer and on at least one side of the resonant electrode, wherein the reflective grating is configured to reflect acoustic waves excited by the resonant electrode to generate a standing wave signal. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of this disclosure and are not intended to limit this disclosure.

[0021] Figure 1 A schematic diagram illustrating the impedance characteristics of a piezoelectric antenna provided in at least one embodiment of this disclosure;

[0022] Figure 2 A three-dimensional structural schematic diagram of a piezoelectric antenna provided for at least one embodiment of this disclosure;

[0023] Figure 3 for Figure 2 A top view of the piezoelectric antenna shown;

[0024] Figure 4 A top view of another piezoelectric antenna provided in at least one embodiment of this disclosure;

[0025] Figure 5 A top view of yet another piezoelectric antenna provided in at least one embodiment of this disclosure;

[0026] Figure 6A three-dimensional structural schematic diagram of another piezoelectric antenna provided in at least one embodiment of the present disclosure;

[0027] Figure 7 A schematic block diagram of an electronic device provided for at least one embodiment of this disclosure;

[0028] Figure 8 A schematic flowchart illustrating a method for fabricating a piezoelectric antenna according to at least one embodiment of this disclosure;

[0029] Figure 9 A schematic flowchart illustrating the fabrication process of a piezoelectric resonator in a piezoelectric antenna, provided for at least one embodiment of this disclosure;

[0030] Figure 10 A schematic flowchart illustrating another piezoelectric antenna fabrication process provided for at least one embodiment of this disclosure;

[0031] Figure 11 This is a schematic diagram illustrating the fabrication process of a piezoelectric antenna according to at least one embodiment of the present disclosure;

[0032] Figure 12 A schematic flowchart illustrating another piezoelectric antenna fabrication process provided in at least one embodiment of this disclosure; and

[0033] Figure 13 A test curve of the radiation performance of a piezoelectric antenna provided for at least one embodiment of this disclosure. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0035] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0036] Currently, the main solutions for acoustically excited antennas operating in the tens of megahertz to gigahertz frequency band include the following:

[0037] (1) Bulk acoustic wave excited magnetoelectric antenna: Based on the magnetic moment excited radiation of the bulk acoustic wave mode, it is mainly divided into two types of structures: thin film bulk acoustic wave resonator with suspension structure and solid assembly type resonator. It requires the use of piezoelectric / magnetostrictive heterojunction.

[0038] (2) Surface acoustic wave excited magnetoelectric antenna: Based on the magnetic moment excitation radiation of the surface acoustic wave mode, a piezoelectric / magnetostrictive heterojunction is required; and

[0039] (3) Voltage-type acoustic wave mediated piezoelectric antenna: Based on the external electromagnetic wave electric field to excite surface acoustic waves, the receiving voltage is enhanced.

[0040] However, the inventors of this disclosure discovered through research that:

[0041] For bulk acoustic wave / surface acoustic wave excited magnetoelectric antennas (collectively referred to as "acoustic-excited magnetoelectric antennas"), their radiation originates from the magnetic moment oscillation of the piezoelectric / magnetostrictive heterojunction. On the one hand, due to the interfacial mismatch between the materials, the strain transfer loss between the piezoelectric and magnetoelectric phases greatly limits the antenna's radiation capability. Furthermore, the radiation capability of this magnetoelectric antenna depends on high-performance magnetoelectric composite materials, which require high-quality material parameters such as soft magnetic properties and piezoelectric coefficient. However, the development of high-performance magnetoelectric composite materials is difficult and costly. On the other hand, the fabrication process of bulk acoustic wave excited magnetoelectric antennas is cumbersome and costly, and there are significant challenges in device consistency and yield, which is not conducive to the large-scale and mass production of antennas. Although the fabrication of surface acoustic wave excited magnetoelectric antennas is relatively simple, it still requires multiple photolithography masking processes (such as depositing magnetic thin films), and the device's quality factor is low, resulting in weaker antenna radiation capability.

[0042] For voltage-type acoustic wave-mediated antennas (also known as "acoustic-mediated piezoelectric antennas"), although they have solved the problem of complex manufacturing process to some extent, the opposite electric field directions between the resonant electrodes (such as interdigital electrodes) on the resonator of the antenna will cause the radiation to cancel each other in the far field, thereby weakening the overall radiation performance of the antenna.

[0043] Furthermore, the current sizes of both acoustically excited magnetoelectric antennas and acoustically mediated piezoelectric antennas are concentrated in the range of one-thousandth to one-hundredth of the electromagnetic wavelength. Due to the small radiating aperture (effective radiating area), the antenna gain is low, making it difficult to meet the needs of practical applications.

[0044] Embodiments of this disclosure provide a piezoelectric antenna, which includes a piezoelectric layer, a piezoelectric resonator, and an external radiator. The piezoelectric resonator is disposed on a first surface of the piezoelectric layer and includes a first terminal, a resonant electrode, a second terminal, and at least one ground loop. The first terminal is electrically connected to the resonant electrode and is configured to apply an alternating voltage generated by an input radio frequency signal to the resonant electrode. The resonant electrode is surrounded by at least one ground loop and is configured to excite the piezoelectric layer to generate acoustic resonance under the action of the alternating voltage. The second terminal is electrically connected to the resonant electrode and is configured to output a current generated by the piezoelectric layer on the resonant electrode. The external radiator is electrically connected to the second terminal and is configured to conduct current to radiate electromagnetic waves.

[0045] The embodiments of this disclosure also provide a method for fabricating a piezoelectric antenna and an electronic device including the piezoelectric antenna.

[0046] The piezoelectric antenna provided in at least one embodiment of this disclosure combines a surface acoustic wave resonator with an external radiator, utilizing the impedance characteristics at the resonance point of the surface acoustic wave as a "medium" to effectively enhance the current on the surface of the external radiator, thereby achieving effective electromagnetic radiation of the entire antenna. Furthermore, the radiation size of the piezoelectric antenna provided in at least one embodiment of this disclosure can be extended from the typical size of an acoustic resonator (less than one-hundredth of the electromagnetic wave wavelength) to the order of one-hundredth to one-tenth of the electromagnetic wave wavelength, achieving a larger radiation aperture and thus more effective radiation.

[0047] The present disclosure will now be described through several specific embodiments. To keep the following description of the embodiments of the present disclosure clear and concise, detailed descriptions of known functions and known components may be omitted. When any component of an embodiment of the present disclosure appears in more than one drawing, the component is represented by the same or similar reference numerals in each drawing.

[0048] For example, the following description uses a piezoelectric antenna that is "based on a surface acoustic resonator with interdigitated electrodes and the external radiator is separately disposed from the surface acoustic resonator".

[0049] Figure 1 This is a schematic diagram of the impedance characteristics of a piezoelectric antenna provided in at least one embodiment of the present disclosure.

[0050] It should be noted that the mediating effect of an acoustic resonator refers to utilizing the impedance characteristics (i.e., reference impedance) resulting from the resonance of the acoustic resonator. Figure 1 The relationship between impedance and frequency shown in the figure is at the acoustic resonant frequency (i.e., Figure 1 The impedance exhibits a minimum at the resonant frequency (i.e., at the anti-resonant frequency). Figure 1 The acoustic resonator exhibits a maximum impedance at its anti-resonance point, and the impedance phase at the resonant frequency and anti-resonant frequency is biased. Since the input alternating voltage remains constant, the current on the surface of the acoustic resonator is significantly enhanced at the resonant frequency. In this process, the acoustic resonator does not act as the magnetic moment driver in a traditional acoustically excited antenna, but rather as an intermediary to enhance the current, thereby improving radiation performance. However, it should be understood that the resonator structure for exciting acoustic resonance in this embodiment can also be a bulk acoustic resonator (e.g., a thin-film bulk acoustic resonator, a solid-mounted bulk acoustic resonator, etc.), and this embodiment does not limit this.

[0051] Figure 2 This is a three-dimensional structural schematic diagram of a piezoelectric antenna provided for at least one embodiment of the present disclosure.

[0052] For example, such as Figure 2 As shown, at least one embodiment of the piezoelectric antenna provided in this disclosure includes a piezoelectric layer 100, a piezoelectric resonator 110 (represented by a "dashed box"), and an external radiator 120. The piezoelectric layer 100 includes two surfaces facing each other. The piezoelectric resonator 110 is disposed on the first surface of the piezoelectric layer 100 (e.g., the upper surface of the piezoelectric layer) and includes a first terminal 1101, a resonant electrode 1102, a second terminal 1103, and at least one (e.g., Figure 2 Two grounding loops, 1104a and 1104b, are shown.

[0053] For example, such as Figure 2 As shown, the first terminal 1101 is electrically connected to the resonant electrode 1102 and is configured to apply an alternating voltage generated by the input radio frequency signal to the resonant electrode 1102. The resonant electrode 1102 is surrounded by ground loops 1104a and 1104b and is configured to excite the piezoelectric layer 100 to generate acoustic resonance under the action of the alternating voltage. The second terminal 1103 is electrically connected to the resonant electrode 1102 and is configured to output the current generated by the piezoelectric layer 100 on the resonant electrode 1102. The external radiator 1102 is electrically connected to the second terminal 1103 and is configured to conduct the current to radiate electromagnetic waves.

[0054] For example, under the excitation of an external alternating voltage, acoustic wave mechanical resonance is generated in the piezoelectric layer 100. Due to the piezoelectric effect, a low-impedance path is provided between the resonant electrodes, which excites a strong current on the upper surface of the acoustic resonator.

[0055] For example, such as Figure 2 As shown, grounding loops 1104a and 1104b are used to achieve effective grounding with the outside. The first terminal 1101 and the second terminal 1103 are respectively set at a preset distance from the two terminals of the grounding loops 1104a and 1104b.

[0056] For example, an alternating voltage can be input via a 50-ohm (Ω) transmission line, which can be electrically connected to the first terminal 1101 via wire bonding. It should be noted that the 50-ohm (Ω) transmission line includes a signal line and a ground line, wherein the signal line is bonded to the first terminal 1101, and the ground line is bonded to at least one terminal of ground loops 1104a and 1104b.

[0057] For example, in one possible implementation, the external radiator is disposed separately from the piezoelectric layer, and the external radiator is electrically connected to the second terminal via an encapsulated interconnect. For example, the connection via the encapsulated interconnect can include wire bonding and flip-chip bonding. The encapsulated interconnect can include leads, vias, solder balls, bumps, etc., and this disclosure does not limit the scope of the embodiments.

[0058] Figure 3 for Figure 2 The image shows a top view of a piezoelectric antenna. For example, as shown... Figure 3 As shown, the external radiator 120 is separately disposed from the piezoelectric layer 110 and electrically connected to the second terminal 1103 via wire bonding. For example, the wire bonding method can include through-holes or external wiring. Using through-holes prevents the wires from being exposed, improving safety and aesthetics, while external wiring prioritizes ease of wiring and operability. The specific method can be chosen based on actual conditions, and the embodiments of this disclosure do not limit the wire bonding method. It should also be noted that, in addition to wire bonding, the external radiator 120 can also achieve electrical connection to the second terminal 1103 through packaging interconnection methods such as flip-chip bonding, and the embodiments of this disclosure do not limit this. Separating the external radiator from the piezoelectric layer improves the operability of the piezoelectric antenna. The size of the external radiator can be replaced and adjusted based on actual conditions, enhancing the stable operation of the antenna system in different application scenarios and improving the adaptability and reliability of the antenna system.

[0059] For example, in one possible implementation, an external radiator is disposed on the first surface of the piezoelectric layer and electrically connected to a second terminal via a metal wiring.

[0060] Figure 4 This is a top view of another piezoelectric antenna provided for at least one embodiment of the present disclosure. For example, as... Figure 4 As shown, the external radiator 120, like the piezoelectric resonator 110, is disposed on the first surface of the piezoelectric layer (e.g., the upper surface of the piezoelectric layer 110), and is electrically connected to the second terminal 1103 of the piezoelectric resonator 110 via metal wiring. By coplanarly disposing the external radiator and the piezoelectric resonator on the piezoelectric layer, the antenna can be fabricated as a single unit, simplifying the fabrication process and improving fabrication efficiency.

[0061] For example, in one possible implementation, the piezoelectric antenna of at least one embodiment of this disclosure further includes a reflective grating disposed on a first surface of the piezoelectric layer, on at least one side of the resonant electrode, and configured to reflect acoustic waves excited by the resonant electrode to generate a standing wave signal.

[0062] Figure 5 This is a top view of yet another piezoelectric antenna provided in at least one embodiment of the present disclosure. Exemplarily, Figure 5 It is also a scheme to separate the external radiator from the piezoelectric layer.

[0063] like Figure 5 As shown, relative to Figure 4 , Figure 5 Reflective gratings 1105a and 1105b are added, which are also disposed on the first surface of the piezoelectric layer 110 (e.g., the upper surface of the piezoelectric layer 110) and respectively on both sides of the resonant electrode 1102. For example, the reflective gratings 1105a and 1105b can be formed from metal lines on the upper surface of the piezoelectric layer 100 (e.g., strip-shaped reflective gratings), or they can be formed as reflective gratings by etching channels on the upper surface of the piezoelectric layer 100 (e.g., grooved reflective gratings). For example, to increase reflection efficiency, a multi-layered Bragg reflector can also be used as the reflective grating. This structure, composed of alternately stacked layers of different acoustic impedance materials, can more effectively reflect sound waves within a specific frequency band.

[0064] For example, such as Figure 5 As shown, the reflective grids 1105a and 1105b have the same structure. For example, they are generally rectangular and include multiple parallel and spaced strip structures (grid bars); for another example, the reflective grids 1105a and 1105b can be surrounded by ground loops 1104a and 1104b and resonant electrode 1102, respectively.

[0065] For example, in order to efficiently reflect sound waves of a specific frequency, the width and spacing of the reflective grating need to be optimized according to the wavelength of the target sound wave. Typically, the period of the grating (i.e., the grating width plus the spacing between adjacent gratings) can be an integer multiple of half the wavelength of the surface acoustic wave.

[0066] For example, in Figure 5 In the piezoelectric antenna shown, reflector gratings 1105a and 1105b serve to reflect surface acoustic waves generated from the piezoelectric layer 110. By precisely controlling the positions of reflector gratings 1105a and 1105b and the width and spacing of their grating strips, the reflected acoustic waves can be phase-matched with newly generated acoustic waves, thereby forming a standing wave mode. This helps to enhance signals at specific frequencies and improve the selectivity and quality factor of the resonator.

[0067] For example, in one possible implementation, the external radiator can be a planar structure or a three-dimensional structure. For example, the planar structure can be a square, a circle, a meandering line, or other regular or irregular shapes. The three-dimensional structure can be a multi-layered planar structure, a metal rod, a metal ring, a metal spiral, or a printed circuit board (PCB), etc., and the embodiments of this disclosure are not limited thereto.

[0068] For example, in one possible implementation, the size of the external radiator is at least one of the following: less than one-hundredth of the operating electromagnetic wavelength, greater than or equal to one-hundredth of the operating electromagnetic wavelength and less than or equal to one-tenth of the operating electromagnetic wavelength, and greater than one-tenth of the operating electromagnetic wavelength, wherein the operating electromagnetic wavelength refers to the wavelength of the electromagnetic wave generated by the piezoelectric antenna. It should be noted that the above... Figures 2-5 The dimensions of the external radiator shown are merely illustrative. The maximum size of the external radiator can be designed to be greater than one-tenth of the operating electromagnetic wavelength, which is much larger than the size of the piezoelectric resonator (i.e., less than one-hundredth of the operating electromagnetic wavelength). By changing the size of the external radiator, a larger radiation aperture can be obtained, extending to the order of one-hundredth to one-tenth of the electromagnetic wave wavelength, significantly improving radiation performance.

[0069] For example, in one possible implementation, the resonant electrode includes a pair of opposing first interdigital electrodes and second interdigital electrodes, the first interdigital electrodes being electrically connected to a first terminal and the second interdigital electrodes being electrically connected to a second terminal.

[0070] For example, with Figure 5 The piezoelectric antenna shown is an example. Figure 5As shown, the resonant electrode 1102 is an interdigital electrode, which includes a pair of opposing first interdigital electrodes 1102a and second interdigital electrodes 1102b. The multiple electrodes of each electrode are parallel to each other and staggered. The first interdigital electrode 1102a is electrically connected to the first terminal 1101, and the second interdigital electrode 1102b is electrically connected to the second terminal 1103.

[0071] For example, such as Figure 5 As shown, the resonant electrodes 1102 are arranged horizontally and periodically, and their width can be, for example, [missing information]. , This refers to the acoustic wavelength at the corresponding operating frequency.

[0072] It should be noted that the aforementioned interdigitated electrodes can be spaced apart. The deployed rectangular interdigitated electrodes can also be interdigitated electrodes with split fingers; they can be interdigitated electrodes with uniform length, or they can be apodization weighted interdigitated electrodes with different lengths and widths that vary according to a certain rule; they can also be interdigitated electrodes with dummy fingers or interdigitated electrodes with top loads. The embodiments of this disclosure do not limit the specific structure of the interdigitated electrodes.

[0073] For example, such as Figure 5 As shown, the piezoelectric antenna provided in at least one embodiment of this disclosure is a surface acoustic wave device, and its operating frequency is affected by the period length of the interdigitated electrodes, as shown by the following formula:

[0074]

[0075] in, This indicates the operating frequency of the surface acoustic wave device. This represents the sound velocity corresponding to the piezoelectric layer material. This indicates the period length of the interdigitated electrode.

[0076] The operating frequency of a piezoelectric antenna can be adjusted by the period length of the interdigital electrodes, thus offering a wide adjustment range. Depending on the application, the frequency range can be flexibly adjusted from megahertz to gigahertz. Furthermore, when fabricating piezoelectric antennas using semiconductor processes, different operating frequencies can be fabricated in a single process by changing the period length of the interdigital electrodes, thereby improving wafer utilization efficiency and reducing costs.

[0077] For example, in the acoustically mediated piezoelectric antenna provided in at least one embodiment of this disclosure, the resonant modes of the surface acoustic waves generated by its interdigital electrodes after applying an alternating voltage may include, for example, Rayleigh wave modes, horizontal shear wave modes, or Leff wave modes.

[0078] It should be understood that the embodiments of this disclosure do not limit the resonant modes of the acoustic surface waves that excite the piezoelectric antenna. Accordingly, the operating frequency of the piezoelectric antenna provided in the embodiments of this disclosure may include, for example, the resonant frequencies corresponding to the fundamental mode and higher-order modes of Rayleigh wave mode, horizontal shear wave mode, or Leff wave mode.

[0079] For example, in the piezoelectric antenna provided in at least one embodiment of this disclosure, the piezoelectric material forming the piezoelectric layer includes, for example, bulk piezoelectric materials, such as aluminum nitride (AlN), zinc oxide (ZnO), gallium nitride (GaN), lead zirconate titanate (PZT), lead magnesium niobate-lead titanate (PMN-PT), lithium niobate (LiNbO3) with different orientations, lithium tantalate (LiTaO3) with different orientations, and quartz, etc. Taking lithium niobate (LiNbO3) with different orientations as an example, "different orientations" refers to wafers cut from lithium niobate crystals according to different crystal planes or directions. By selecting an appropriate cutting angle, the performance of the lithium niobate material can be optimized to meet the requirements of specific applications. For example, for surface acoustic wave excited piezoelectric antennas, some commonly used cutting angles include 36°YX cut, 42°YX cut, etc. Lithium tantalate (LiTaO3) is similar to lithium niobate (LiNbO3), and will not be described further here. Piezoelectric materials may also include, for example, composite substrates with bonded or grown piezoelectric thin films, to adjust the performance of the piezoelectric antenna by changing the substrate configuration.

[0080] In some embodiments of the piezoelectric antennas provided in this disclosure, for example, the piezoelectric material forming the piezoelectric layer adopts a composite structure of piezoelectric thin film materials stacked on a high-velocity acoustic substrate. This can improve the performance quality factor of the piezoelectric antenna. For example, for commonly used lithium niobate with 36°YX and 42°YX tangential orientations, its surface acoustic velocity is approximately between 3000 and 3500 m / s. For example, selecting a material with high thermal conductivity as the substrate can improve the power tolerance of the piezoelectric antenna. For example, for silicon carbide (SiC), its thermal conductivity is approximately between 80 and 120 W / m·K. Piezoelectric thin film materials include, for example, aluminum nitride (AlN), zinc oxide (ZnO), gallium nitride (GaN), lead zirconate titanate (PZT), lead magnesium niobate-lead titanate (PMN-PT), lithium niobate (LiNbO3) with different tangential orientations, and lithium tantalate (LiTaO3); substrates used to support piezoelectric thin films include, for example, silicon (Si), silicon oxide (SiO), silicon carbide (SiC), silicon nitride (SiN), diamond, sapphire, etc.

[0081] For example, in the piezoelectric antenna provided in at least one embodiment of this disclosure, the materials used to form the interdigital electrodes include, for example, titanium (Ti), aluminum (Al), copper (Cu), platinum (Pt), gold (Au), silver (Ag), molybdenum (Mo), and any alloy thereof.

[0082] It should be noted that the above description of the materials used in the piezoelectric layer and interdigitated electrodes of the piezoelectric antenna provided in the embodiments of this disclosure should not be construed as a limitation of this disclosure.

[0083] For example, in one possible implementation, the resonant electrode includes a top electrode and a bottom electrode arranged vertically opposite each other, and the piezoelectric antenna also includes a suspended piezoelectric film, with the top electrode and the bottom electrode respectively disposed on the two side surfaces of the suspended piezoelectric film.

[0084] Figure 6 This is a three-dimensional structural schematic diagram of another piezoelectric antenna provided in at least one embodiment of the present disclosure. For example, as... Figure 6 As shown, the acoustic resonance of the piezoelectric antenna can also be excited by a thin-film bulk acoustic resonator, which includes a silicon substrate 210, a piezoelectric thin film 220, a first terminal 230, an air cavity 240, ground loops 250a and 205b, a bottom electrode 260, a top electrode 270, a through hole 280, a second terminal 290, and an external radiator 300.

[0085] The top electrode 270 and the bottom electrode 260 are arranged vertically opposite to each other to form the resonant electrodes of the thin-film bulk acoustic resonator. The bottom electrode 260 is formed on the silicon substrate 210, the piezoelectric thin film 220 is formed on the bottom electrode 260, the top electrode 270 is formed on the piezoelectric thin film 220, the piezoelectric thin film 220a in the air cavity 240 is in a suspended state, and the bottom electrode 260 and the top electrode 270 are electrically connected through the through hole 280.

[0086] For example, during operation, an alternating voltage is applied to the surfaces of the top electrode 270 and bottom electrode 260 of the thin-film bulk acoustic resonator. The piezoelectric thin film 220 generates longitudinal bulk acoustic waves through the inverse piezoelectric effect, achieving acoustic resonance at the resonant frequency and inducing a strong current at the top electrode 270. This strong current is introduced into the external radiator 300 via the second terminal 290 through, for example, wire bonding, increasing the radiation aperture and significantly improving radiation performance. It should be noted that, in addition to wire bonding, the second terminal 290 can also be electrically connected to the external radiator 300 through other packaged interconnects; details can be found in the above embodiments and will not be elaborated here. In some examples, the external radiator can also be disposed on the surface of the piezoelectric thin film and electrically connected to the second terminal through metal wiring.

[0087] For example, in Figure 6 In the piezoelectric antenna shown, the resonant modes of the bulk acoustic waves generated by the top electrode 270 and bottom electrode 260 after an alternating voltage is applied may include, for example, Lamb wave modes, thickness stretching bulk acoustic wave modes, or thickness shearing bulk acoustic wave modes.

[0088] It should be understood that the above embodiments of this disclosure do not limit the resonant modes of the bulk acoustic waves that excite the piezoelectric antenna. Accordingly, the operating frequency of the piezoelectric antenna provided in the above embodiments of this disclosure may include, for example, the resonant frequencies corresponding to the fundamental mode and higher-order modes of the Lamb wave mode, the thickness stretching body acoustic wave mode, or the thickness shear body acoustic wave mode.

[0089] For example, it should be noted that, unlike the surface acoustic wave resonators mentioned above, the operating frequency (i.e., the frequency of the radiated electromagnetic wave) of the piezoelectric antenna can be adjusted by changing the thickness and type of the piezoelectric thin film under the action of the thin film, so as to achieve frequency customization.

[0090] For example, the resonator structure for exciting acoustic resonance disclosed herein can also be a solid-assembly type bulk acoustic wave resonator. The difference between the solid-assembly type bulk acoustic wave resonator and the aforementioned thin-film bulk acoustic wave resonator is that the piezoelectric thin film of the solid-assembly type bulk acoustic wave resonator is a single, integral layer, without... Figure 6 The air cavity 240 shown also has a reflective layer structure on the lower surface of the bottom electrode 260. This reflective layer structure is, for example, composed of multiple layers of materials with different acoustic impedances stacked alternately. The function of these layers is to reflect sound waves propagating downwards from the piezoelectric film, causing them to return into the piezoelectric film, thereby reducing sound wave energy loss and improving resonance efficiency. In other words, the thin-film bulk acoustic resonator achieves acoustic reflection through air, while the solid-mount type bulk acoustic resonator achieves acoustic reflection by depositing multiple layers of thin films with high and low acoustic impedances at the bottom. The remaining structures are the same and will not be described further here.

[0091] It should be noted that the specific structures of the surface acoustic wave resonator, thin film bulk acoustic wave resonator, and solid-mounted acoustic wave resonator described above are merely exemplary, and the embodiments disclosed herein are not intended to limit them.

[0092] This place is Figure 3 Taking the piezoelectric antenna shown as an example, the function of the acoustically mediated resonator in the embodiments of this disclosure is illustrated. In one possible case, Figure 3The piezoelectric antenna shown does not include the piezoelectric layer 100; that is, it directly connects, for example, a 50-ohm (Ω) transmission line to the external radiator. Since energy matching requires the antenna size to be half the electromagnetic wavelength to achieve resonance and couple energy, and in this case, the external radiator is much smaller than half the electromagnetic wavelength (i.e., impedance mismatch), causing most of the energy to be reflected. Consequently, the actual current received by the external radiator is very small, resulting in poor radiation performance. At least one embodiment of this disclosure places an acoustically mediated resonator before the external radiator. Due to the impedance characteristics of the piezoelectric resonator, effective coupling of the input energy can be achieved, and a strong current is excited on the surface of the piezoelectric resonator, which is then output to the external radiator for effective radiation. It can be understood that the acoustically mediated resonator in the embodiments of this disclosure provides a path for energy conduction to the external radiator.

[0093] The piezoelectric antenna provided in this disclosure combines a surface acoustic wave resonator with an external radiator, utilizing the impedance characteristics at the resonance point of the surface acoustic wave as a "medium" to effectively enhance the current on the surface of the external radiator, thereby achieving effective electromagnetic radiation of the entire antenna. Furthermore, the radiation size of the piezoelectric antenna provided in at least one embodiment of this disclosure can be expanded from the typical size of an acoustic resonator (less than one-hundredth of the electromagnetic wave wavelength) to the order of one-hundredth to one-tenth of the electromagnetic wave wavelength, achieving a larger radiation aperture and thus more effective radiation.

[0094] At least one embodiment of this disclosure also provides an electronic device. Figure 7 A schematic block diagram of an electronic device provided for at least one embodiment of this disclosure, such as Figure 7 As shown, the electronic device 400 includes the piezoelectric antenna 410 described in any of the above embodiments.

[0095] For example, the electronic device 400 may also include a signal application circuit configured to apply an electrical signal to the piezoelectric antenna 410. For instance, the signal application circuit may be an AC signal application circuit, and may include modules such as signal generation, power amplification, filters, and baseband chips.

[0096] For example, the electronic device 400 can be an on-chip fully integrated wireless transceiver module, which can be applied to devices limited by antenna size, such as mobile devices (e.g., smartphones, tablets, and wearable devices), Internet of Things devices, and implantable medical devices (e.g., pacemakers, neurostimulators).

[0097] Figure 8 This is a schematic flowchart illustrating a method for fabricating a piezoelectric antenna according to at least one embodiment of the present disclosure, including steps S500-S520.

[0098] Step S500: Form a piezoelectric layer.

[0099] For example, a piezoelectric single-crystal substrate is used, or a piezoelectric layer is prepared on a substrate, such as a silicon substrate, a ceramic substrate, an organic sheet, etc.

[0100] Step S510: A piezoelectric resonator is formed on the first surface of the piezoelectric layer. The piezoelectric resonator includes a first terminal, a resonant electrode, a second terminal, and at least one ground loop.

[0101] The first terminal is electrically connected to the resonant electrode and is configured to apply an alternating voltage generated by the input radio frequency signal to the resonant electrode. The resonant electrode is surrounded by at least one ground loop and is configured to excite the piezoelectric layer to generate acoustic resonance under the action of the alternating voltage. The second terminal is electrically connected to the resonant electrode and is configured to output the current generated by the piezoelectric layer on the resonant electrode.

[0102] Step S520: An external radiator is formed. This external radiator is electrically connected to the second terminal and is configured to conduct current to radiate electromagnetic waves.

[0103] Figure 9 This is a schematic flowchart illustrating the fabrication process of a piezoelectric resonator in a piezoelectric antenna, provided for at least one embodiment of this disclosure. For example, as... Figure 9 As shown, in the method for fabricating a piezoelectric antenna provided in some embodiments of this disclosure, an example of forming a piezoelectric resonator in step S510 includes steps S600-S620:

[0104] Step S600: A first photoresist pattern is formed on the first surface of the piezoelectric layer;

[0105] Step S610: A first metal layer is formed on the first surface of the piezoelectric layer;

[0106] Step S620: Peel off the photoresist and the first metal layer on the photoresist to obtain the piezoelectric resonator.

[0107] Figure 9The process for forming a piezoelectric resonator shown is called a metal lift-off patterning process. The metal lift-off patterning process includes: using photolithography on a substrate to expose and develop a photoresist layer to obtain a patterned photoresist pattern; using this photoresist pattern as a mask, depositing a target material (e.g., metals such as copper, aluminum, and titanium) onto the entire substrate surface including the mask using a coating process; then using a stripper (also known as a release solution) to dissolve the photoresist and remove the photoresist pattern and the target material thereon, while retaining the target material in the areas not covered by the photoresist pattern, thereby obtaining the target patterned structure. Thus, this process mainly includes photoresist coating, development, removal of the undercoat, formation of a metal layer, and lift-off (stripping). The above process can pattern materials that are difficult to etch (e.g., precious metals, materials that are difficult to corrode, or materials for which the etchant does not have sufficient selectivity for other exposed materials). The embodiments of this disclosure do not limit the photoresist morphology, photoresist thickness, or the process for the material to be lifted off.

[0108] Metal stripping patterning can theoretically eliminate the etching step. The process is simple and low-cost, making it suitable for patterning materials that are difficult to etch (such as precious metals, materials that are difficult to corrode, and materials for which the etchant does not have sufficient selectivity for other exposed materials).

[0109] In at least one embodiment, prior to step S600, a piezoelectric layer is formed on a substrate, such as a silicon substrate, a ceramic substrate, an organic sheet, etc.

[0110] It should be noted that after the piezoelectric resonator is fabricated, the external radiator can be fabricated separately using other additive or subtractive manufacturing processes, such as electroplating or low-temperature co-fired ceramics. It can then be electrically connected to the second terminal in the piezoelectric resonator by means of wire bonding, for example.

[0111] For example, external radiators can be fabricated on separate printed circuit boards, which not only offers high design freedom but also utilizes mature and low-cost processing technologies, facilitating large-scale production and application.

[0112] Figure 10 This is a schematic flowchart illustrating another piezoelectric antenna fabrication process provided for at least one embodiment of this disclosure. For example, as... Figure 10 As shown, in the piezoelectric antenna fabrication method provided in some embodiments of this disclosure, the formation of the piezoelectric resonator in step S510 and the formation of the external radiator in step S520 are fabricated as a single unit, for example including steps S700-S720:

[0113] Step S700: A second photoresist pattern is formed on the first surface of the piezoelectric layer;

[0114] Step S710: A second metal layer is formed on the first surface of the piezoelectric layer;

[0115] Step S720: Strip the photoresist and the first metal layer on the photoresist to obtain the piezoelectric resonator and the external radiator, wherein the external radiator is electrically connected to the second terminal through metal wiring.

[0116] For example, steps S700-S720 described above can still be used. Figure 9 The metal stripping and patterning process described above is used for preparation, and will not be elaborated here.

[0117] In the preparation method provided in the above embodiments of this disclosure, the piezoelectric resonator and the external radiator are integrated by using the same series of processes, which not only simplifies the process flow but also significantly improves the production yield.

[0118] Figure 11 This is a schematic diagram illustrating the fabrication process of a piezoelectric antenna according to at least one embodiment of this disclosure. Wherein, as... Figure 11 As shown, the unfilled matrix pattern represents the piezoelectric substrate, the diagonally filled rectangular pattern represents the photoresist, and the horizontally filled rectangular pattern represents the metal layer. The steps can correspond, for example, to... Figure 9 Steps S600-S620 shown or Figure 10 The steps S700-S720 are shown. First, a photoresist pattern is formed on the upper surface of the piezoelectric substrate; then, a metal layer is deposited on the upper surface of the piezoelectric substrate with the patterned photoresist; finally, the photoresist and the metal layer on the photoresist are stripped to obtain the patterned metal layer. For example, the patterned metal layer can be the piezoelectric resonator in the piezoelectric antenna described above, or a piezoelectric resonator and an external radiator.

[0119] Figure 12 This is a schematic flowchart illustrating another piezoelectric antenna fabrication process provided in at least one embodiment of the present disclosure.

[0120] In the piezoelectric antenna fabrication methods provided in some embodiments of this disclosure, the piezoelectric resonator can also be, for example... Figure 12 The metal etching patterning process shown is formed.

[0121] like Figure 12 As shown, the electrode layer is formed using a metal etching patterning process, mainly including steps S800-S820:

[0122] Step S800: A metal layer is formed on the first surface of the piezoelectric layer;

[0123] Step S810: A photoresist pattern is formed on the surface of the metal layer;

[0124] Step S820: Etch the patterned metal layer to obtain the piezoelectric resonator.

[0125] Metal etching patterning is a process that selectively removes unwanted material with the help of a photoresist mask, thus preserving the desired fine patterns. A patterned photoresist structure is formed on a wafer where the target material has already grown, serving as a mask using photolithography. Dry or wet etching is then used to remove material from areas not protected by the photoresist mask. Finally, a stripper is used to dissolve the photoresist, yielding the target patterned structure. Metal etching patterning better ensures the growth quality and surface smoothness of the metal thin film. Furthermore, the etching process guarantees the quality of the sidewalls of the patterned metal pattern, avoiding process problems caused by sidewall curling and burrs. The disadvantages of metal etching are its complexity, high cost, and the difficulty in patterning small-sized electrodes.

[0126] In comparison, the metal pattern left in the metal lift-off patterning process is the metal portion on the substrate piezoelectric layer, which is preserved to form the final pattern. The metal etching patterning process is the opposite of the lift-off process; there is photoresist on the metal layer, and the metal pattern is defined by dry or wet etching processes.

[0127] It should be understood that the methods for fabricating piezoelectric resonators in piezoelectric antennas provided in some embodiments of this disclosure include using metal etching patterning processes or metal stripping patterning, and the methods for fabricating piezoelectric resonators should not be regarded as limitations on this disclosure.

[0128] Taking surface acoustic wave resonators as an example, the fabrication process of the piezoelectric resonator (i.e., acoustically mediated resonator) in the piezoelectric antenna proposed in at least one embodiment of this disclosure involves only single-step photolithography, single-step thin film deposition, and single-step metal patterning on the piezoelectric substrate. Compared with the complex process of multi-step photolithography, multi-step thin film deposition, and multi-step metal patterning required for acoustically excited magnetoelectric antennas with magnetoelectric heterojunctions as the core, the process complexity of the embodiments of this disclosure is significantly simplified. Therefore, it can achieve improved fabrication consistency and yield, further reduce costs, and is suitable for mass production and application.

[0129] The method for fabricating a piezoelectric antenna provided in at least one embodiment of this disclosure may further include the following step 900.

[0130] Step S900: A reflective grating is formed on the first surface of the piezoelectric layer and on at least one side of the resonant electrode.

[0131] For example, a reflective grating is configured to reflect acoustic waves excited by resonant electrodes to generate standing wave signals, and the formed reflective grating can be referenced. Figure 5 The reflective gratings 1105a and 1105b.

[0132] In the piezoelectric antenna fabrication method provided in at least one embodiment of this disclosure, an example of step S900 may be one of the following steps S910 or S920.

[0133] Step S910: Form a metal line on the first surface of the piezoelectric layer.

[0134] Step S920: Form a channel or step on the first surface of the piezoelectric layer.

[0135] Figure 13 A test curve of the radiation performance of a piezoelectric antenna provided for at least one embodiment of this disclosure.

[0136] like Figure 13 As shown, at the acoustic resonant frequency of 450 MHz, compared to an external radiator without an inserted surface acoustic wave resonator (dashed line, i.e., electrically directly connected to the external radiator via alternating voltage), the piezoelectric antenna (solid line) based on a surface acoustic wave resonator and electrically connected to the external radiator provided in this embodiment improves the radiation performance by 8 dB, demonstrating a significant advantage in radiation performance.

[0137] Although the present disclosure has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to the embodiments of the present disclosure, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present disclosure are within the scope of protection claimed by the present disclosure.

[0138] The following points should be noted regarding this disclosure:

[0139] (1) The accompanying drawings of the embodiments of this disclosure only involve the structures involved in the embodiments of this disclosure. Other structures can be referred to the general design.

[0140] (2) For clarity, the thickness of layers or regions in the drawings used to describe embodiments of the present disclosure is enlarged or reduced, i.e., these drawings are not drawn to actual scale.

[0141] (3) Where there is no conflict, the embodiments of this disclosure and the features in the embodiments can be combined with each other to obtain new embodiments.

[0142] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. The scope of protection of this disclosure should be determined by the scope of protection of the claims.

Claims

1. A piezoelectric antenna, comprising: piezoelectric layer; A piezoelectric resonator, disposed on a first surface of the piezoelectric layer, includes a first terminal, a resonant electrode, a second terminal, and at least one ground loop, wherein... The first terminal is electrically connected to the resonant electrode and is configured to apply an alternating voltage generated by the input radio frequency signal to the resonant electrode. The resonant electrode is surrounded by the at least one ground loop and is configured to excite the piezoelectric layer to generate acoustic resonance under the action of the alternating voltage. The second terminal is electrically connected to the resonant electrode and is configured to output current generated by the piezoelectric layer on the resonant electrode; as well as An external radiator, electrically connected to the second terminal, is configured to conduct the current to radiate electromagnetic waves.

2. The piezoelectric antenna according to claim 1, wherein, The external radiator is separately disposed from the piezoelectric layer, and the external radiator is electrically connected to the second terminal through an encapsulated interconnect.

3. The piezoelectric antenna according to claim 1, wherein, The external radiator is disposed on the first surface of the piezoelectric layer and is electrically connected to the second terminal via a metal wiring.

4. The piezoelectric antenna according to claim 1, further comprising: A reflective grating is disposed on a first surface of the piezoelectric layer, on at least one side of the resonant electrode, and is configured to reflect acoustic waves excited by the resonant electrode to generate a standing wave signal.

5. The piezoelectric antenna according to claim 4, wherein, The reflective grid is surrounded by the at least one ground loop and the resonant electrode.

6. The piezoelectric antenna according to any one of claims 1-5, wherein, The external radiator can be a planar or three-dimensional structure.

7. The piezoelectric antenna according to any one of claims 1-5, wherein, The size of the external radiator is at least one of the following: less than one percent of the working electromagnetic wavelength, greater than or equal to one percent of the working electromagnetic wavelength and less than or equal to one-tenth of the working electromagnetic wavelength, and greater than one-tenth of the working electromagnetic wavelength, wherein the working electromagnetic wavelength is the wavelength of the electromagnetic wave generated by the piezoelectric antenna.

8. The piezoelectric antenna according to any one of claims 1-5, wherein, The resonant electrode includes a pair of opposing first interdigital electrodes and second interdigital electrodes. The first interdigital electrode is electrically connected to the first terminal. The second interdigital electrode is electrically connected to the second terminal.

9. The piezoelectric antenna according to any one of claims 1-5, wherein, The resonant electrode includes a top electrode and a bottom electrode arranged vertically opposite each other. The piezoelectric antenna also includes a suspended piezoelectric film, with the top electrode and the bottom electrode respectively disposed on the two sides of the suspended piezoelectric film.

10. The piezoelectric antenna according to any one of claims 1-5, wherein, The resonant electrode includes a top electrode and a bottom electrode arranged vertically opposite each other, with the top electrode and bottom electrode respectively disposed on two side surfaces of the piezoelectric layer. The piezoelectric antenna also includes a reflective layer disposed on the lower surface of the bottom electrode.

11. An electronic device comprising the piezoelectric antenna according to any one of claims 1-10.

12. A method for fabricating a piezoelectric antenna, comprising: Formation of a piezoelectric layer; A piezoelectric resonator is formed on the first surface of the piezoelectric layer, wherein the piezoelectric resonator includes a first terminal, a resonant electrode, a second terminal, and at least one ground loop. The first terminal is electrically connected to the resonant electrode and is configured to apply an alternating voltage generated by the input radio frequency signal to the resonant electrode. The resonant electrode is surrounded by the at least one ground loop and is configured to excite the piezoelectric layer to generate acoustic resonance under the action of the alternating voltage. The second terminal is electrically connected to the resonant electrode and is configured to output a current generated by the piezoelectric layer on the resonant electrode; and An external radiator is formed, wherein the external radiator is electrically connected to the second terminal and is configured to conduct the current to radiate electromagnetic waves.

13. The method according to claim 12, wherein, The formation of a piezoelectric resonator on the first surface of the piezoelectric layer includes: A first photoresist pattern is formed on the first surface of the piezoelectric layer; A first metal layer is formed on the first surface of the piezoelectric layer; and The photoresist and the first metal layer on the photoresist are peeled off to obtain the piezoelectric resonator.

14. The method according to claim 13, wherein, The external radiator and the piezoelectric layer are fabricated separately, and the method further includes: An interconnect is provided to electrically connect the external radiator to the second terminal.

15. The method according to claim 12, wherein, The piezoelectric resonator and the external radiator are integrally fabricated, wherein forming the piezoelectric resonator on the first surface of the piezoelectric layer and forming the external radiator include: A second photoresist pattern is formed on the first surface of the piezoelectric layer; A second metal layer is formed on the first surface of the piezoelectric layer; and The photoresist and the second metal layer on the photoresist are stripped to obtain the piezoelectric resonator and the external radiator, wherein the external radiator is electrically connected to the second terminal via a metal wiring.

16. The method according to any one of claims 12-15, further comprising: A reflective grating is formed on the first surface of the piezoelectric layer and on at least one side of the resonant electrode. The reflective grating is configured to reflect the acoustic waves excited by the resonant electrode to generate a standing wave signal.

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