Tunable magnetoelectric antenna and preparation method thereof

Abstract

The invention discloses a tunable magnetoelectric antenna and a preparation method thereof. The tunable magnetoelectric antenna comprises a substrate, wherein a selected surface of the substrate is provided with a first region and a second region which are sequentially arranged along a first direction; the magnetoelectric antenna is arranged in the first area, and a resonant cavity is formed between the magnetoelectric antenna and the first area; and the trench capacitor is arranged in the second area, and the trench capacitor is connected with the bulk acoustic wave excitation magnetoelectric antenna in series. The tunable magnetoelectric antenna is formed by connecting the magnetoelectric antenna and the ferroelectric capacitor in series, the ferroelectric capacitor is of a groove structure, the capacitance value of the capacitor can be effectively increased, and transverse leakage of sound waves can be restrained.

Description

Technical Field

[0001] The present invention particularly relates to a tunable magnetoelectric antenna and a preparation method thereof, belonging to the technical field of electronic devices. Background Art

[0002] With the rapid development of wireless communication technology, the research and development of antennas is moving towards chip-based, high-gain, broadband and intelligent. Traditional antennas are based on oscillating current radiation. Only when the size of the antenna is comparable to the wavelength of the electromagnetic wave can it effectively radiate and receive electromagnetic waves. This working principle essentially limits the miniaturization of antennas and makes it difficult to meet the needs of the new generation of antenna chip technology.

[0003] Exploring new mechanisms for electromagnetic wave radiation and reception that can effectively reduce the size of antennas has important theoretical and engineering significance. Magnetoelectric antennas based on acoustic wave excitation and magnetoelectric coupling effects achieve the radiation and reception of electromagnetic signals through the electric-acoustic-magnetic and magnetic-acoustic-electric energy conversion processes, overcoming ohmic losses. They have the advantages of high radiation efficiency, small size (2-3 orders of magnitude smaller than traditional antennas), and simple matching circuits. This type of antenna can also be chip-based using mature micro-electromechanical system (MEMS) process technology, which is one of the important directions for antenna miniaturization and has great application prospects and economic value in digital fields such as the Internet of Things and virtual reality.

[0004] Acoustically excited magnetoelectric antennas radiate time-varying fields generated by oscillating electric / magnetic dipole moments. When receiving signals, it converts the magnetic field component of electromagnetic waves into acoustic waves, and then outputs them as voltage through the piezoelectric effect; conversely, when transmitting signals, it converts electrical signals into strain through the inverse piezoelectric effect, transmits them to the magnetic material and stimulates it to oscillate magnetization and radiate electromagnetic waves. Since the wavelength of acoustic waves is about 5 orders of magnitude smaller than that of electromagnetic waves, the size of magnetoelectric antennas is expected to be reduced to 1 / 100 of traditional micro-antennas. The radiation process of magnetoelectric antennas does not involve current conduction, which is expected to greatly improve radiation efficiency and circumvent the limitations of platform effects. In addition, the impedance of magnetoelectric antennas can be adjusted by changing parameters such as film thickness and device size, simplifying the external matching network.

[0005] Magnetoelectric materials based on MEMS technology are obtained by combining piezoelectric films and magnetostrictive films. The size of the magnetoelectric coupling coefficient determines the efficiency of magnetoelectric coupling. When the magnetostrictive film is fixed, the larger the piezoelectric coefficient of the piezoelectric film, the larger the magnetoelectric coupling coefficient. At present, the commonly used magnetostrictive films in the industry are FeGa, FeGaB and FeGaC, and the commonly used piezoelectric films are AlN, AlScN and PZT. Among them, AlN and AlScN have received widespread attention because they are expected to be combined with CMOS technology and can be prepared by low-temperature technology. The problem with AlN is that d 33 It is relatively small, about 4.9pC / N. Although Sc doping can be used to increase the d33 However, the preparation of AlScN thin films with high Sc content is difficult and prone to abnormally oriented grains; and Sc is a rare metal and is expensive. The problem with PZT is that it contains the Pb element, which poses an environmental problem.

[0006] Magnetoelectric antenna is an important technology route for antenna miniaturization, which is mainly composed of piezoelectric resonant devices and magnetostrictive films. The commonly used magnetostrictive films in the industry are FeGa, FeGaB and FeGaC, and the commonly used piezoelectric films are AlN, AlScN and PZT. Among them, AlN and AlScN have attracted widespread attention because they are expected to be combined with CMOS technology and can be prepared by low-temperature technology. However, the frequency of existing magnetoelectric antennas is difficult to adjust and inconvenient to use. Therefore, it is of great significance to develop high-performance magnetoelectric antennas with tuning functions. Summary of the invention

[0007] The main purpose of the present invention is to provide a tunable magnetoelectric antenna and a preparation method thereof, so as to overcome the deficiencies in the prior art.

[0008] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0009] A first aspect of an embodiment of the present invention provides a tunable magnetoelectric antenna, comprising:

[0010] A substrate, a selected surface of the substrate having a first region and a second region sequentially disposed along a first direction;

[0011] A magnetoelectric antenna is disposed in the first region, and a resonant cavity is formed between the magnetoelectric antenna and the first region;

[0012] A trench capacitor is disposed in the second region, and the trench capacitor is connected in series with the bulk acoustic wave excited magnetoelectric antenna.

[0013] A second aspect of an embodiment of the present invention provides a method for preparing the tunable magnetoelectric antenna, which comprises:

[0014] forming a magnetoelectric antenna on an epitaxial substrate;

[0015] A resonant cavity is formed in a first area on the surface of the substrate, and a trench capacitor is formed in a second area on the surface of the substrate;

[0016] The magnetoelectric antenna is bonded to the first region of the substrate so that the magnetoelectric antenna covers the resonant cavity, the magnetoelectric antenna is connected in series with the trench capacitor, and the epitaxial substrate is removed.

[0017] Compared with the prior art, the advantages of the present invention include: a tunable magnetoelectric antenna provided by the present invention is composed of a magnetoelectric antenna and a ferroelectric capacitor connected in series, wherein the ferroelectric capacitor has a groove structure, which can effectively increase the capacitance value and suppress the lateral leakage of sound waves. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a structural schematic diagram of a tunable magnetoelectric antenna provided by an embodiment of the present invention;

[0019] Figure 2a , Figure 2b , Figure 2c The schematic diagrams of the structures of the magnetoelectric antenna excited by Lamb waves are respectively a single-sided interdigital electrode, a double-sided interdigital electrode, and a double-sided interdigital electrode in which both the piezoelectric layer and the electrode are periodically patterned;

[0020] Figure 3a is a schematic structural diagram of another tunable magnetoelectric antenna provided by an embodiment of the present invention;

[0021] Figure 3b is a top view of another tunable magnetoelectric antenna provided by an embodiment of the present invention;

[0022] Figure 4a is a schematic diagram of the principle of another tunable magnetoelectric antenna provided by an embodiment of the present invention;

[0023] Figure 4b yes Figure 4a A partial enlarged view of

[0024] Figure 5 is an equivalent circuit diagram of a tunable magnetoelectric antenna provided by an embodiment of the present invention;

[0025] Figure 6 is a relationship curve between an admittance curve and a ferroelectric capacitance of a tunable magnetoelectric antenna provided by an embodiment of the present invention;

[0026] Figure 7 is a displacement distribution diagram of a tunable magnetoelectric antenna provided by an embodiment of the present invention;

[0027] Figure 8 It is a schematic diagram of the manufacturing process of a tunable magnetoelectric antenna provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In view of the deficiencies in the prior art, the inventor of this case has proposed the technical solution of the present invention after long-term research and extensive practice. The technical solution, its implementation process and principle will be further explained as follows.

[0029] A first aspect of an embodiment of the present invention provides a tunable magnetoelectric antenna, comprising:

[0030] A substrate, a selected surface of the substrate having a first region and a second region sequentially disposed along a first direction;

[0031] A magnetoelectric antenna is disposed in the first region, and a resonant cavity is formed between the magnetoelectric antenna and the first region;

[0032] A trench capacitor is disposed in the second region, and the trench capacitor is connected in series with the bulk acoustic wave excited magnetoelectric antenna.

[0033] Further, the magnetoelectric antenna completely covers the resonant cavity;

[0034] Furthermore, the magnetoelectric antenna includes a first electrode, a gallium oxide piezoelectric layer, a second electrode and a magnetostrictive layer that match each other.

[0035] Furthermore, the first electrode, the gallium oxide piezoelectric layer, the second electrode and the magnetostrictive layer are sequentially stacked in the first region along a second direction and completely cover the resonant cavity, and the second direction is perpendicular to the first direction.

[0036] Furthermore, the resonant cavity is completely disposed in the substrate.

[0037] Furthermore, the magnetoelectric antenna includes a magnetoelectric antenna excited by a bulk acoustic wave, a magnetoelectric antenna excited by a surface acoustic wave, or a magnetoelectric antenna excited by a Lamb wave.

[0038] Furthermore, the gallium oxide piezoelectric layer is formed of ε-Ga2O3 material doped with specified elements, wherein the atomic ratio of the specified elements to the Ga element is 1%-50%, and the specified elements include at least one of magnesium and scandium. By doping with the specified elements, the piezoelectric coefficient of the material can be increased, thereby improving the energy conversion efficiency of the magnetoelectric antenna.

[0039] Furthermore, the trench capacitor includes a trench structure arranged in the second area of ​​the substrate, and a third electrode, a dielectric structure layer and a fourth electrode stacked in sequence on the trench wall of the trench structure, the dielectric structure layer includes at least one stacked ferroelectric layer and at least one dielectric layer, the ferroelectric layer is formed of a low acoustic impedance material, and the third electrode and the fourth electrode are formed of a high acoustic impedance material.

[0040] Furthermore, the dielectric structure layer includes a plurality of ferroelectric layers and a plurality of dielectric layers, and the plurality of ferroelectric layers and the plurality of dielectric layers are alternately stacked in sequence.

[0041] Furthermore, the thickness and / or material of at least two of the ferroelectric layers are different.

[0042] Further, the material of the ferroelectric layer includes at least one of aluminum scandium nitride, hafnium oxide, zirconium oxide, hafnium zirconium oxide, hafnium silicon oxide, hafnium nitride and zirconium nitride, but is not limited thereto.

[0043] Furthermore, the material of the dielectric layer includes at least one of aluminum oxide, aluminum nitride, titanium oxide and silicon oxide, but is not limited thereto.

[0044] Furthermore, the thickness of the third electrode, the ferroelectric layer and the fourth electrode is 1 / 4 of the acoustic wavelength corresponding to the center frequency of the magnetoelectric antenna.

[0045] Furthermore, the depth of the groove structure is 1-10 times the acoustic wavelength corresponding to the center frequency of the substrate.

[0046] Furthermore, the aspect ratio of the groove structure is 1-50.

[0047] Furthermore, the minimum vertical distance between the groove structure and the resonant cavity in the first direction is 1-50 times the acoustic wavelength corresponding to the center frequency corresponding to the substrate.

[0048] Further, the second area is arranged on one side of the first area, or the second area is arranged around the first area.

[0049] Furthermore, the groove structure is a long strip structure, or the groove structure is a ring structure arranged around the resonant cavity.

[0050] Furthermore, the annular groove structure and the resonant cavity are arranged concentrically.

[0051] Furthermore, the trench capacitor includes a plurality of the trench structures, a plurality of elongated trench structures are sequentially arranged along the first direction, and a plurality of annular trench structures are concentrically arranged.

[0052] A second aspect of an embodiment of the present invention provides a method for preparing the tunable magnetoelectric antenna, which comprises:

[0053] forming a magnetoelectric antenna on an epitaxial substrate;

[0054] A resonant cavity is formed in a first area on the surface of the substrate, and a trench capacitor is formed in a second area on the surface of the substrate;

[0055] The magnetoelectric antenna is bonded to the first region of the substrate so that the magnetoelectric antenna covers the resonant cavity, the magnetoelectric antenna is connected in series with the trench capacitor, and the epitaxial substrate is removed.

[0056] Furthermore, the method for preparing the tunable magnetoelectric antenna also includes:

[0057] Firstly, a two-dimensional material layer is fabricated on the epitaxial substrate, and then a magnetoelectric antenna is fabricated on the two-dimensional material layer;

[0058] After bonding the magnetoelectric antenna to the first region of the substrate, the epitaxial substrate is removed using the two-dimensional material layer as a peeling layer.

[0059] Furthermore, the material of the two-dimensional material layer includes at least one of boron nitride (BN) and graphene, but is not limited thereto.

[0060] Furthermore, the material of the epitaxial substrate includes at least one of sapphire, silicon carbide, gallium nitride and silicon, but is not limited thereto.

[0061] The technical solution, its implementation process and principles, etc. will be further explained below in conjunction with the accompanying drawings and specific implementation cases. Unless otherwise specified, the epitaxial growth process and equipment, etching process and equipment, etc. used in the embodiments of the present invention are all known in the art.

[0062] See also Figure 1 In a more specific implementation, a tunable magnetoelectric antenna includes a substrate and a bulk acoustic wave excited magnetoelectric antenna and a trench capacitor integrated on the substrate. The bulk acoustic wave excited magnetoelectric antenna and the trench capacitor are connected in series. The trench structure of the trench capacitor itself can effectively increase the capacitance of the capacitor and suppress the lateral leakage of sound waves. Specifically, by tuning based on trench-type ferroelectric capacitors, a thinner dielectric structure layer can be used to achieve a larger capacitance, and thus it can also work at a higher frequency. The capacitor with a trench structure will produce multiple air interfaces and can effectively suppress the lateral propagation of sound waves.

[0063] In this embodiment, the bulk acoustic wave excited magnetoelectric antenna and the trench capacitor are arranged on the same substrate, and the trench capacitor is located along the periphery of the bulk acoustic wave excited magnetoelectric antenna and perpendicular to the acoustic wave leakage direction of the bulk acoustic wave excited magnetoelectric antenna. Specifically, the selected surface of the substrate (for example, the top surface of the substrate) has a first area and a second area arranged in sequence along a first direction, the first area has a resonant cavity, the bulk acoustic wave excited magnetoelectric antenna is arranged in the first area and completely covers the resonant cavity, the trench capacitor is arranged in the second area, the first area is located on one side of the second area along the first direction, or the first area and the second area are distributed around the periphery of the first area.

[0064] In this embodiment, if Figure 2a , Figure 2b , Figure 2cAs shown, the bulk acoustic wave excited magnetoelectric antenna includes a first electrode, a gallium oxide piezoelectric layer, a second electrode and a magnetostrictive layer. The first electrode and the second electrode can both be metal electrodes. The gallium oxide piezoelectric layer is formed by an ε-Ga2O3 material doped with a specified element, wherein the atomic ratio of the specified element to the Ga element is 1%-50%, and the specified element includes at least one of magnesium and scandium. The material of the magnetostrictive layer includes at least one of FeGa, FeGaB and FeGaC, but is not limited thereto. Specifically, the first electrode, the gallium oxide piezoelectric layer, the second electrode and the magnetostrictive layer can be stacked in sequence along the second direction in the first region, the first electrode can directly cover the resonant cavity, and the second direction is perpendicular to the first direction. Specifically, the first electrode and the second electrode can also be arranged on the same side of the gallium oxide piezoelectric layer, at least one of the first electrode and the second electrode can be a patterned interdigital structure, and the gallium oxide piezoelectric layer can also have a patterned structure. The specific pattern structures of the first electrode, the second electrode, the gallium oxide piezoelectric layer, the second electrode and the magnetostrictive layer are not specifically limited herein.

[0065] In this example, see Figure 1 The trench capacitor includes a trench structure arranged in the second area of ​​the substrate, and a third electrode, a dielectric structure layer and a fourth electrode stacked in sequence on the trench wall of the trench structure, the dielectric structure layer includes at least one stacked ferroelectric layer and at least one dielectric layer, the ferroelectric layer is formed of a low acoustic impedance material, and the third electrode and the fourth electrode are formed of a high acoustic impedance material, wherein the thickness of the third electrode, the ferroelectric layer and the fourth electrode is 1 / 4 of the acoustic wavelength corresponding to the center frequency of the magnetoelectric antenna.

[0066] Specifically, the dielectric structure layer includes a plurality of ferroelectric layers and a plurality of dielectric layers, and the plurality of ferroelectric layers and the plurality of dielectric layers are alternately stacked in sequence. The size of the ferroelectric domain can be regulated by adjusting the thickness of the ferroelectric layer, thereby adjusting the capacitance characteristics of the ferroelectric layer. Exemplarily, the material of the ferroelectric layer can be at least one of aluminum scandium nitride, hafnium oxide, zirconium oxide, hafnium zirconium oxide, hafnium silicon oxide, hafnium nitride and zirconium nitride, and the material of the dielectric layer can be at least one of aluminum oxide, aluminum nitride, titanium oxide and silicon oxide. Specifically, the thickness and / or material of at least two of the ferroelectric layers are different. Specifically, the third electrode and the fourth electrode are both metal electrodes. Exemplarily, the materials of the third electrode and the fourth electrode can be molybdenum, platinum, tungsten, etc.

[0067] Exemplarily, the parameters of several ferroelectric layer materials and characteristic acoustic impedance of air used in the present invention are shown in Table 1, and the parameters of several materials used for the third electrode and the fourth electrode are shown in Table 2.

[0068] Table 1 Parameters of ferroelectric layer materials and characteristic acoustic impedance of air

[0069]

[0070] Table 2 Parameters of acoustic impedance of electrode materials

[0071]

[0072] It can be concluded from Tables 1 and 2 that the acoustic impedance of metals is greater than that of ferroelectric materials. In order to achieve a larger acoustic impedance mismatch, metal electrodes are preferably made of large acoustic impedance materials such as platinum and tungsten. Among ferroelectric materials, zirconium oxide has a smaller acoustic impedance and is preferably used as a ferroelectric layer. In addition, in order to improve the ferroelectric properties of zirconium oxide, a small amount of hafnium can be doped into zirconium oxide to form hafnium zirconium oxide (HZO).

[0073] For details, please refer to Figure 3a and Figure 3b , the groove structure is a long strip structure, or the groove structure is an annular structure arranged around the resonant cavity, the groove structure of the long strip structure is arranged on one side of the resonant cavity, the annular groove structure is arranged around the periphery of the resonant cavity, and is preferably arranged concentrically with the resonant cavity. More specifically, the groove capacitor may also include a plurality of the groove structures, a plurality of long strip groove structures are arranged in sequence on one side of the resonant cavity along the first direction, a plurality of annular groove structures all surround the resonant cavity and are arranged concentrically, preferably, the surrounding groove structure is arranged concentrically with the resonant cavity. Specifically, the depth of the groove structure is 1-10 times the acoustic wavelength of the center frequency corresponding to the substrate, and the aspect ratio of the groove structure is 1-50. Within this range, the larger the aspect ratio of the groove structure, the larger the capacitance can be achieved in a smaller area, which is beneficial to saving area. However, if the aspect ratio of the groove structure is too large, the bottom of the groove structure cannot obtain a complete film due to the aspect ratio limitation of the film preparation, and the ferroelectric sandwich capacitor preparation process cannot be completed; the minimum vertical distance between the groove structure and the resonant cavity in the first direction is 1-50 times the acoustic wavelength of the center frequency corresponding to the substrate. It should be noted that the minimum vertical distance between the groove structure and the resonant cavity in the first direction refers to the vertical distance between the groove structure closest to the resonant cavity and the resonant cavity. If the minimum vertical distance between the groove structure and the resonant cavity is too small, the device structure will be unstable; if the distance is too large, part of the sound wave will be lost between the body acoustic wave excitation magnetoelectric antenna and the groove capacitor.

[0074] For details, please refer to Figure 4a , Figure 4bThe trench capacitor in the embodiment of the present invention is a sandwich structure. It should be noted that when the acoustic impedances of the materials of the multilayer structure contained in the trench capacitor are different, the sound waves will be reflected at the interface where the acoustic impedance changes. The greater the impedance difference on both sides of the interface, the more the sound waves will be reflected. The sandwich structure of the trench capacitor in the embodiment of the present invention is three different materials, plus air, which means four reflection interfaces. For transverse sound waves, each reflection interface can effectively reflect transversely propagating sound waves and suppress the lateral propagation of sound waves. Furthermore, each layer of the trench capacitor can be set as a transverse Bragg reflection layer to form total reflection.

[0075] The MBVD equivalent circuit of a tunable magnetoelectric antenna provided in a typical implementation case of the present invention is as follows: Figure 5 As shown in Figure 2, the relationship between the resonant frequency of the tunable magnetoelectric antenna and the capacitance of the ferroelectric capacitor is as follows: Figure 6 shown.

[0076] Specifically, the present invention sets a trench capacitor on the left side of the resonant cavity, but does not set it on the right side. The displacement distribution diagram of the tunable antenna obtained by performing a simulation test on the acoustic wave leakage effect of the tunable magnetoelectric antenna is as follows: Figure 7 As shown, from Figure 7 It can be seen that the lateral propagation of the sound wave is significantly suppressed by adding the trench capacitor on one side.

[0077] In a typical implementation case, please refer to Figure 8 , a preparation process of a tunable magnetoelectric antenna may include the following steps:

[0078] 1) First, a two-dimensional thin film material (such as boron nitride (BN) and graphene) is epitaxially grown on an epitaxial substrate (such as sapphire, silicon carbide, gallium nitride and silicon substrate, etc.) as a peeling layer, and then an ε-Ga2O3 thin film material is epitaxially grown to form a piezoelectric layer. The advantage of this method is that after bonding, the epitaxial substrate can be directly peeled off.

[0079] 2) Using a physical vapor deposition (PVD) process to grow electrode materials and perform patterning to form a patterned first electrode.

[0080] 3) Selecting a suitable target transfer substrate (ie the aforementioned substrate), the target transfer substrate may be a silicon, glass or silicon carbide substrate layer.

[0081] 4) A groove structure of a resonant cavity and a ferroelectric capacitor is prepared on the target transfer substrate, and a third electrode / ferroelectric layer / dielectric layer / … / ferroelectric layer / dielectric layer / upper electrode is further grown on the groove wall of the groove structure by an ALD process, and a ferroelectric capacitor structure is formed by photolithography and etching processes.

[0082] 5) Bonding the structures obtained in step 2) and step 4) together, and making the first electrode completely cover the resonant cavity.

[0083] 6) Using the lift-off technique, remove the epitaxial substrate from the lift-off layer to obtain the pattern of step 6.

[0084] 7) A magnetostrictive film and a second electrode are grown on the piezoelectric layer using a PVD (Physical Vapor Deposition) process, and patterned to form a magnetoelectric antenna.

[0085] Of course, the magnetoelectric antenna excited by bulk acoustic waves can also be replaced by a magnetoelectric antenna excited by bulk acoustic waves, a magnetoelectric antenna excited by surface acoustic waves, or a magnetoelectric antenna excited by Lamb waves.

[0086] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A tunable magnetoelectric antenna, characterized in that: include: A substrate, a selected surface of the substrate having a first region and a second region sequentially disposed along a first direction; A magnetoelectric antenna is disposed in the first region, and a resonant cavity is formed between the magnetoelectric antenna and the first region; A trench capacitor is disposed in the second region, and the trench capacitor is connected in series with the bulk acoustic wave excited magnetoelectric antenna.

2. The tunable magnetoelectric antenna according to claim 1, characterized in that: The magnetoelectric antenna completely covers the resonant cavity; Preferably, the magnetoelectric antenna comprises a first electrode, a gallium oxide piezoelectric layer, a second electrode and a magnetostrictive layer that match each other; Preferably, the first electrode, the gallium oxide piezoelectric layer, the second electrode and the magnetostrictive layer are sequentially stacked in the first region along a second direction and completely cover the resonant cavity, and the second direction is perpendicular to the first direction; Preferably, the resonant cavity is completely disposed within the substrate; Preferably, the magnetoelectric antenna includes a magnetoelectric antenna excited by bulk acoustic waves, a magnetoelectric antenna excited by surface acoustic waves, or a magnetoelectric antenna excited by Lamb waves.

3. The tunable magnetoelectric antenna according to claim 2, characterized in that: The gallium oxide piezoelectric layer is formed by ε-Ga2O3 material doped with a specified element, wherein the atomic ratio of the specified element to the Ga element is 1%-50%, and the specified element includes at least one of magnesium and scandium.

4. The tunable magnetoelectric antenna according to claim 2, characterized in that: The trench capacitor includes a trench structure arranged in the second area of ​​the substrate, and a third electrode, a dielectric structure layer and a fourth electrode stacked in sequence on the trench wall of the trench structure, the dielectric structure layer includes at least one stacked ferroelectric layer and at least one dielectric layer, the ferroelectric layer is formed of a low acoustic impedance material, and the third electrode and the fourth electrode are formed of a high acoustic impedance material.

5. The tunable magnetoelectric antenna according to claim 4, characterized in that: The dielectric structure layer comprises a plurality of ferroelectric layers and a plurality of dielectric layers, and the plurality of ferroelectric layers and the plurality of dielectric layers are alternately stacked in sequence; Preferably, the thickness and / or material of at least two of the ferroelectric layers are different; Preferably, the material of the ferroelectric layer includes at least one of aluminum scandium nitride, hafnium oxide, zirconium oxide, hafnium zirconium oxide, hafnium silicon oxide, hafnium nitride and zirconium nitride; Preferably, the material of the dielectric layer includes at least one of aluminum oxide, aluminum nitride, titanium oxide and silicon oxide.

6. The magnetoelectric antenna according to claim 4, characterized in that: The thickness of the third electrode, the ferroelectric layer and the fourth electrode is 1 / 4 of the acoustic wavelength corresponding to the center frequency of the magnetoelectric antenna.

7. The magnetoelectric antenna according to claim 4, characterized in that: The depth of the groove structure is 1-10 times the acoustic wavelength corresponding to the center frequency of the substrate; And / or, the aspect ratio of the groove structure is 1-50; And / or, the minimum vertical distance between the groove structure and the resonant cavity in the first direction is 1-50 times the acoustic wavelength corresponding to the center frequency corresponding to the substrate.

8. The magnetoelectric antenna according to claim 4 or 7, characterized in that: The second area is arranged at one side of the first area, or the second area is arranged around the first area; Preferably, the groove structure is a long strip structure, or the groove structure is a ring structure arranged around the resonant cavity; Preferably, the annular groove structure is concentrically arranged with the resonant cavity; Preferably, the trench capacitor comprises a plurality of the trench structures, a plurality of elongated trench structures are sequentially arranged along the first direction, and a plurality of annular trench structures are concentrically arranged.

9. The method for preparing the tunable magnetoelectric antenna according to any one of claims 1 to 8, characterized in that: include: forming a magnetoelectric antenna on an epitaxial substrate; A resonant cavity is formed in a first area on the surface of the substrate, and a trench capacitor is formed in a second area on the surface of the substrate; The magnetoelectric antenna is bonded to the first region of the substrate so that the magnetoelectric antenna covers the resonant cavity, the magnetoelectric antenna is connected in series with the trench capacitor, and the epitaxial substrate is removed.

10. The method for preparing the tunable magnetoelectric antenna according to claim 9, characterized in that: Also includes: Firstly, a two-dimensional material layer is fabricated on the epitaxial substrate, and then a magnetoelectric antenna is fabricated on the two-dimensional material layer; After bonding the magnetoelectric antenna to the first region of the substrate, the epitaxial substrate is removed using the two-dimensional material layer as a peeling layer.

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