Multifunctional metamaterial beam-amplified low-frequency multiferroic mechanical antenna

Abstract

The application discloses a multifunctional metamaterial beam amplified low-frequency multi-ferroelectric mechanical antenna, and relates to the technical field of antennas.The antenna is composed of a grid-shaped shuttle-shaped variable rigidity composite beam composed of a plurality of strong hysteresis magnetostrictive layers / high magnetic permeability magnetostrictive films / piezoelectric layer unit arrays, a first elastic substrate / soft piezoelectric material / second elastic substrate, a permanent magnet, an energy collection circuit and a negative resistance circuit.The elastic standing wave generated by exciting the piezoelectric array is enhanced through the variable rigidity characteristics of the elastic substrate in the composite beam and the strain convergence characteristics of the shuttle-shaped structure to enhance the magnetic moment oscillation effect of the permanent magnet at the end of the beam.The vibration of the permanent magnet and the magnetostriction effect of the magnetostrictive film jointly emit an alternating magnetic field.The planar grid structure and the vertical spiral structure of the metal elastic substrate form a low-frequency magnetic metamaterial through cascaded capacitance to amplify the emitted magnetic field;the soft piezoelectric material generates an alternating voltage when the composite beam vibrates, and the energy collection circuit supplies energy to the negative resistance circuit to further improve the Q value of the metamaterial and the magnetic field amplification effect.

Description

Technical Field

[0001] This application relates to the field of antenna technology, and in particular to a multifunctional metamaterial beam amplification low-frequency multiferroic mechanical antenna. Background Technology

[0002] Radio frequency (RF) communication technologies (such as Bluetooth and 5G) are widely used in daily life, but they suffer from severe path loss in high-conductivity environments such as underground or underwater. In contrast, very low frequency (VLF) communication systems, due to their greater skin depth, are more suitable for wireless communication in underground or underwater environments. However, conventional VLF electrical antennas suffer from large antenna size and high power consumption in order to achieve sufficiently high radiation efficiency, which severely limits the miniaturization and portability of the antennas. Compared with conventional electrical antennas, mechanical antennas, which have emerged in recent years, can achieve low-frequency communication in a very small size. Currently, low-frequency mechanical antennas mainly include rotating permanent magnet antennas driven by external motors and magnetoelectric antennas with resonant piezoelectric layers. Among them, magnetoelectric antennas mainly utilize electromechanical resonance to induce magnetic moment oscillation, which can reduce the size by five orders of magnitude compared with conventional electrical antennas, while significantly reducing power consumption.

[0003] Currently, there are very low frequency (VLF) ME transceivers and magnetoelectric antennas with magnetostrictive layer / piezoelectric layer / magnetostrictive layer structures, but these antenna devices suffer from weak transmitting magnetic fields, which severely restricts the performance of long-distance low-frequency communication. Summary of the Invention

[0004] The purpose of this application is to provide a multifunctional metamaterial beam amplified low-frequency multiferroic mechanical antenna that can amplify the transmitting magnetic field and improve the magnetic field transmission efficiency.

[0005] To achieve the above objectives, this application provides the following solution:

[0006] This application provides a multifunctional metamaterial beam-amplified low-frequency multiferroic mechanical antenna, including a magnetoelectric transmitting array, a composite beam, a metal spiral structure, a permanent magnet, and an energy harvesting circuit.

[0007] The magnetoelectric emission array includes several magnetoelectric emission units, and each magnetoelectric emission unit includes, from top to bottom, a strong hysteresis piezomagnetic layer, a piezomagnetic thin film unit, and a piezoelectric layer; a composite beam is provided between the piezomagnetic thin film unit and the piezoelectric layer;

[0008] The composite beam comprises, from top to bottom, a first elastic substrate, a flexible piezoelectric material PVDF layer, and a second elastic substrate; the first and second elastic substrates are grid structures; one end of the composite beam is fixed to form a cantilever beam, and the beam width gradually decreases from the fixed end to the other free end; the flexible piezoelectric material PVDF layer extends into a rectangular PVDF surface electrode at the free end of the composite beam; the rectangular PVDF surface electrode is connected to a permanent magnet and an energy harvesting circuit.

[0009] The metal spiral structure is vertically disposed on the upper surface of the composite beam and includes several metal spiral units; each metal spiral unit is connected to a lumped capacitor and a negative resistance circuit; the lumped capacitor and the negative resistance circuit are connected in parallel; the rectangular PVDF surface electrode generates an AC voltage when the composite beam vibrates, which powers the negative resistance circuit after passing through the energy harvesting circuit.

[0010] The input end of the piezoelectric layer is connected to an external AC voltage source. During antenna transmission, the piezoelectric layer generates AC strain under AC voltage excitation and transmits it to the piezomagnetic thin film unit, causing magnetic moment oscillation. The composite beam converges the AC strain generated by the magnetoelectric transmitting array, regulates the oscillation of the permanent magnet, and modulates the static magnetic energy of the permanent magnet into an AC magnetic field.

[0011] Optionally, the piezomagnetic thin film unit extends four trapezoidal structures from the edge of the strong hysteresis piezomagnetic layer in all directions, with the narrow end of the trapezoidal structure close to the edge of the strong hysteresis piezomagnetic layer.

[0012] Optionally, the grid structure of the first elastic substrate is arranged in a grid pattern with horizontal and vertical cross-sections, and the metal spiral structure is fixedly connected to the connecting beam between the cross-sections of the grid structure of the first elastic substrate.

[0013] Optionally, the piezomagnetic thin film unit and the piezoelectric layer are bonded to the composite beam.

[0014] Optionally, the metal spiral structure is a square-shaped metal sheet.

[0015] Optionally, the thickness of the first elastic substrate and the second elastic substrate ranges from 0.1 mm to 2 mm.

[0016] Optionally, the piezoelectric layer is made of PZT or PMN-PT piezoelectric material.

[0017] Optionally, the thickness of the strong hysteresis piezomagnetic layer, the piezomagnetic thin film unit, and the piezoelectric layer ranges from 0.1 mm to 2 mm.

[0018] Optionally, the thickness of the flexible piezoelectric PVDF layer ranges from 0.02 mm to 0.2 mm.

[0019] Optionally, the input end of the piezoelectric layer is connected to an external AC voltage source. The AC voltage source excites the elastic standing wave generated by the piezoelectric layer array to enhance the magnetic moment oscillation effect of the permanent magnet at the end of the beam through the variable stiffness characteristics of the elastic substrate in the composite beam and the strain convergence characteristics of the spindle structure. The vibration of the permanent magnet and the magnetostriction effect of the piezoelectric film together generate the emitted AC magnetic field. The piezoelectric layer array is composed of all the piezoelectric layers.

[0020] According to the specific embodiments provided in this application, the following technical effects are disclosed:

[0021] This application provides a multifunctional metamaterial beam-amplified low-frequency multiferroic mechanical antenna. The composite beam, excited by a piezoelectric element array, drives the permanent magnet at its free end to oscillate, generating an alternating magnetic field. The equivalent inductance formed by the grid and metal spiral structure of the elastic substrate, along with the distributed and lumped capacitance formed by the flexible piezoelectric material PVDF layer, together form a low-frequency magnetic metamaterial. This utilizes the negative permeability of the low-frequency magnetic metamaterial to amplify evanescent waves. This not only enhances the static magnetic energy controlling the magnetic moment oscillation of the piezoelectric thin film by strongly converging the magnetic field of adjacent piezoelectric arrays, but also further amplifies the transmitting magnetic field without increasing the number of antennas or power consumption, thus improving transmission efficiency. The flexible piezoelectric material PVDF layer of the composite beam, acting as a piezoelectric material, generates an alternating voltage under alternating strain. After passing through an energy harvesting circuit, this voltage powers a negative resistance circuit. This negative resistance circuit, connected in parallel with the low-frequency magnetic metamaterial, reduces the metamaterial resistance, increasing the Q value and further amplifying the transmitting magnetic field. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A schematic diagram of a multifunctional metamaterial beam magnified low-frequency multiferroic mechanical antenna provided in one embodiment of this application;

[0024] Figure 2 This is a schematic diagram of the structure of a magnetoelectric emission unit provided in an embodiment of this application;

[0025] Figure 3 This is a schematic diagram of the structure of a composite beam provided in one embodiment of this application;

[0026] Figure 4 This is a block diagram of an antenna transmitting system provided in one embodiment of this application.

[0027] Figure label:

[0028] 1—Strong hysteresis piezomagnetic layer; 2—Piezomagnetic thin film unit; 3—Composite beam; 4—Piezoelectric layer; 5—AC voltage source; 6—Permanent magnet; 7—Metal spiral structure; 8—Lumped capacitor; 9—Negative resistance circuit; 10—Energy harvesting circuit; 11—First elastic substrate; 12—Flexible piezoelectric material PVDF layer; 13—Second elastic substrate. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] Conventional magnetoelectric antennas still suffer from the following problems: First, they typically require an external permanent magnet to provide an optimal bias magnetic field to achieve a strong radiation magnetic field at the transmitting end and high sensitivity at the receiving end, but this significantly increases the antenna size and noise. Simultaneously, the magnetic field transmission efficiency of current magnetoelectric antennas remains relatively low, significantly limiting communication distance. Current conventional magnetoelectric antennas are mainly composed of magnetostrictive materials coupled with piezoelectric layers, achieving magnetic field transmission and reception primarily through the inverse magnetoelectric effect at the transmitting end and the magnetoelectric effect at the receiving end. However, there is a lack of research on corresponding arraying technologies, and the weakness of the transmitting magnetic field severely restricts the performance of long-distance low-frequency communication.

[0031] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] In one exemplary embodiment, such as Figure 1 As shown, this application provides a multifunctional metamaterial beam-amplified low-frequency multiferroic mechanical antenna, including a magnetoelectric transmitting array, a composite beam 3, a metal spiral structure 7, a permanent magnet 6, and an energy harvesting circuit 10.

[0033] The magnetoelectric emission array includes several magnetoelectric emission units. For example... Figure 2 As shown, each magnetoelectric emission unit comprises, from top to bottom, a strong hysteresis piezomagnetic layer 1, a piezomagnetic thin film unit 2, and a piezoelectric layer 4. The piezomagnetic thin film unit 2 is an irregularly shaped high-permeability piezomagnetic thin film. The piezomagnetic thin film unit 2 extends from the edge of the strong hysteresis piezomagnetic layer 1 to the surrounding area with four trapezoidal structures. The narrow ends of the trapezoidal structures are close to the edge of the strong hysteresis piezomagnetic layer 1.

[0034] The piezoelectric layer 4 can be made of piezoelectric materials such as lead magnesium niobate (PMN-PT) or lead zirconate titanate (PZT). Here, the thicknesses of the strong hysteresis piezomagnetic layer 1, the piezomagnetic thin film unit 2, and the piezoelectric layer 4 are all in the range of 0.1 mm to 2 mm. The length of the magnetoelectric emission unit is in the range of 5 mm to 100 mm, and the spacing between the magnetoelectric emission units is determined by the set operating frequency. The distance between the center points of two adjacent magnetoelectric emission units is in the width direction of 1 mm to 50 mm and in the length direction of 5 mm to 200 mm.

[0035] A composite beam 3 is disposed between the piezomagnetic thin film unit 2 and the piezoelectric layer 4. For example... Figure 3 As shown, the composite beam 3 includes upper and lower layers of high elastic modulus metal material and a middle layer of low elastic modulus PVDF flexible piezoelectric material. That is, the composite beam 3 includes, from top to bottom, a first elastic substrate 11, a flexible piezoelectric material PVDF layer 12 and a second elastic substrate 13. The thickness of the flexible piezoelectric material PVDF layer 12 is in the range of 0.02 mm to 0.2 mm, and the thickness of the first elastic substrate 11 and the second elastic substrate 13 are both in the range of 0.1 mm to 2 mm.

[0036] The first elastic substrate 11 and the second elastic substrate 13 are grid structures. One end of the composite beam 3 is fixed to form a cantilever beam. The beam width of the composite beam 3 gradually decreases from the fixed end to the other free end, forming a spindle-shaped structure. Thus, the composite beam 3 is a grid-like spindle-shaped variable stiffness cantilever beam. The flexible piezoelectric material PVDF layer 12 extends into a rectangular PVDF surface electrode at the free end of the spindle-shaped composite beam 3. The rectangular PVDF surface electrode is connected to the permanent magnet 6 and the energy harvesting circuit 10. The composite beam 3 utilizes the strain convergence effect and the variable stiffness effect of the spindle structure to significantly improve the driving capability of the piezoelectric layer 4 for the free end permanent magnet 6 unit.

[0037] This application relates to very low frequency (VLF) antennas for wireless communication in special environments such as underground or underwater, and particularly to a high-emission-efficiency low-frequency multiferroic mechanical antenna amplified by a multifunctional metamaterial beam. The multifunctional metamaterial beam amplified low-frequency multiferroic mechanical antenna provided in this application establishes a built-in magnetic field between a strong hysteresis piezomagnetic layer 1 and a piezomagnetic thin film unit 2, achieving optimal contramagnetic-electric performance of the magnetoelectric antenna under zero bias magnetic field. On one hand, under AC voltage excitation, the piezoelectric unit array achieves strong elastic / magnetic field coupling characteristics between array units through the elastic standing wave generated by the elastic substrate and the magnetic field converging effect of the irregularly shaped high-permeability thin film. This enhances the magnetic moment oscillation control of the piezomagnetic thin film, achieving nonlinear growth of the transmitted field strength with the number of units. This overcomes the shortcomings of weak magnetic moment energy control by a single magnetoelectric antenna and a single elastic field, significantly improving magnetic field transmission efficiency. On the other hand, the composite beam 3 undergoes bending vibration under the AC strain of the piezoelectric unit array. Through the variable stiffness effect and the strain converging effect of the spindle structure, the swing amplitude of the permanent magnet 6 at the free end is amplified, generating an AC magnetic field.

[0038] In a specific example, the permanent magnet 6 can be a square prism or other shapes with an omnidirectional magnetic moment.

[0039] The piezomagnetic thin film unit 2 and the piezoelectric layer 4 are bonded to the composite beam 3. Specifically, the strong hysteresis piezomagnetic layer 1, the piezomagnetic thin film unit 2, and the piezoelectric layer 4 are bonded at the intersections, and a metal spiral structure 7 is fixed to the connecting beam between the intersections, with the axis of the metal spiral structure 7 parallel to the direction of the connecting beam.

[0040] The first elastic substrate 11 and the second elastic substrate 13 are arranged in a grid pattern with alternating horizontal and vertical directions. The metal spiral structure 7 is fixedly connected to the connecting beams between the intersections of the grid structure of the first elastic substrate 11. Furthermore, the metal spiral structure 7 is vertically disposed on the upper surface of the composite beam 3, i.e., vertically disposed on the first elastic substrate 11, and includes several metal spiral units. In addition to the distributed capacitance formed by the flexible piezoelectric material PVDF layer 12 of the composite beam 3, an additional lumped capacitor 8 is connected in series to adjust the resonant frequency of the low-frequency magnetic supermaterial. Each metal spiral unit is connected to a lumped capacitor 8 and a negative resistance circuit 9, which are connected in parallel. The rectangular PVDF surface electrode generates an AC voltage when the composite beam vibrates, which powers the negative resistance circuit 9 after passing through the energy harvesting circuit 10. The metal spiral structure 7 is a U-shaped metal sheet. The metal spiral structure 7, the first elastic substrate 11, and the second elastic substrate 13 are made of the same material, and can be a metal material with high elastic modulus and high conductivity. The side length of the metal spiral structure 7 is in the range of 5mm to 50mm, and the width is in the range of 1mm to 100mm.

[0041] An AC voltage source 5 is connected to the input terminal of the piezoelectric layer 4. During antenna transmission, the piezoelectric layer 4 generates AC strain under AC voltage excitation and transmits it to the piezomagnetic thin film unit 2, causing magnetic moment oscillation. The composite beam 3 gathers the AC strain generated by the magnetoelectric transmitting array, regulates the oscillation of the permanent magnet 6, and modulates the static magnetic energy of the permanent magnet 6 into an AC magnetic field. The voltage amplitude of the AC voltage source 5 does not exceed 200V.

[0042] The AC voltage source 5 excites the piezoelectric layer array (the piezoelectric layer array is composed of all piezoelectric layers 4) to generate an elastic standing wave. The variable stiffness characteristics of the elastic substrate in the composite beam 3 and the strain convergence characteristics of the spindle structure enhance the magnetic moment oscillation effect of the permanent magnet 6 at the end of the beam. Here, the vibration of the permanent magnet 6 and the magnetostriction effect of the piezoelectric thin film together generate the emitted AC magnetic field.

[0043] like Figure 4 As shown, during antenna transmission, an AC voltage source 5 first generates an AC voltage to excite the piezoelectric layer 4 array, which in turn generates AC strain. The AC strain generated by the piezoelectric layer 4 array arranged at a specific interval on the lower surface of the composite beam 3 is superimposed and converged through the composite beam 3, driving the magnetic moment resonance of the corresponding piezomagnetic thin film unit 2 on the upper surface. Here, the bias magnetic field of each piezomagnetic thin film unit 2 is provided by the non-volatile static magnetic energy of the strong hysteresis piezomagnetic layer 1, and there is a strong magnetic field coupling effect between multiple piezomagnetic thin film units 2. More importantly, in order to further enhance the strong magnetic field coupling effect between the magnetoelectric units and the total transmission magnetic field, this embodiment uses the grid-shaped spindle-shaped variable stiffness composite beam 3 to converge the AC strain generated by the magnetoelectric transmitting antenna array to control the swing of the permanent magnet 6 at the free end of the cantilever beam, modulating the static magnetic energy of the permanent magnet 6 into an AC magnetic field.

[0044] The multifunctional metamaterial beam-amplified low-frequency multiferroic mechanical antenna provided in this application consists of a grid-like spindle-shaped variable stiffness composite beam 3 composed of multiple strong hysteresis piezomagnetic layers 1 / high permeability piezomagnetic thin films 2 / piezoelectric layers 4 unit arrays, a first elastic substrate 11 / flexible piezoelectric material PVDF layer 12 / second elastic substrate 13, a permanent magnet 6, an energy harvesting circuit 10, and a negative resistance circuit 9. The composite beam 3 is fixedly clamped at its wider end, and a rectangular PVDF surface electrode extends from its narrower end to connect to the permanent magnet 6. Under the AC strain of the aforementioned piezoelectric layer 4, the composite beam 3 generates bending vibration (the elastic substrate generates a bending vibration mode). Through the cross-sectional variable stiffness effect and the strain convergence effect of the horizontal spindle-shaped structure, the amplitude of the permanent magnet 6 at the free end is amplified, thereby enhancing the magnetic moment oscillation of the permanent magnet 6. The permanent magnet 6 and the piezomagnetic thin film unit 2 work together to generate an AC magnetic field.

[0045] Meanwhile, the flexible piezoelectric material PVDF layer 12 in the composite beam 3 forms a distributed capacitance as a dielectric material. The planar grid structure and the vertical metal spiral structure of the elastic substrate, together with their own distributed capacitance and the series lumped capacitance 8, form a low-frequency magnetic supermaterial (i.e., the planar grid structure and the vertical metal spiral structure 7 of the elastic substrate form a low-frequency magnetic supermaterial through the cascaded external lumped capacitance 8 and their own distributed capacitance). The negative permeability characteristics of the low-frequency magnetic supermaterial are used to amplify the evanescent wave and amplify the emitted magnetic field.

[0046] At this time, the magnetic field generated by the permanent magnet 6 and the piezomagnetic film is amplified through the metamaterial beam. This can not only gather the magnetic field generated by the adjacent piezomagnetic array and enhance the static magnetic energy that controls the magnetic moment oscillation of the piezomagnetic film unit 2, but also further amplify the transmission magnetic field without increasing the number of antennas and power consumption, thus improving the magnetic field transmission efficiency. On the other hand, PVDF, as a piezoelectric material, i.e., the flexible piezoelectric material PVDF layer 12 generates an AC voltage under the AC strain action when the composite beam 3 vibrates. After passing through the energy harvesting circuit 10, it supplies power to the negative resistance circuit 9. The negative resistance circuit 9 is connected in parallel with the low-frequency magnetic metamaterial, which reduces the resistance of the metamaterial and increases the Q value of the metamaterial. Thus, the transmission magnetic field is further amplified without consuming additional energy.

[0047] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0048] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A multifunctional metamaterial beam-amplified low-frequency multiferroic mechanical antenna, characterized in that, The multifunctional metamaterial beam-amplified low-frequency multiferroic mechanical antenna includes a magnetoelectric transmitting array, a composite beam, a metal spiral structure, a permanent magnet, and an energy harvesting circuit. The magnetoelectric emission array includes several magnetoelectric emission units, and each magnetoelectric emission unit includes, from top to bottom, a strong hysteresis piezomagnetic layer, a piezomagnetic thin film unit, and a piezoelectric layer; a composite beam is provided between the piezomagnetic thin film unit and the piezoelectric layer; The composite beam comprises, from top to bottom, a first elastic substrate, a flexible piezoelectric material PVDF layer, and a second elastic substrate; the first and second elastic substrates are grid structures; one end of the composite beam is fixed to form a cantilever beam, and the beam width gradually decreases from the fixed end to the other free end; the flexible piezoelectric material PVDF layer extends into a rectangular PVDF surface electrode at the free end of the composite beam; the rectangular PVDF surface electrode is connected to a permanent magnet and an energy harvesting circuit. The metal spiral structure is vertically disposed on the upper surface of the composite beam and includes several metal spiral units; each metal spiral unit is connected to a lumped capacitor and a negative resistance circuit; the lumped capacitor and the negative resistance circuit are connected in parallel; the rectangular PVDF surface electrode generates an AC voltage when the composite beam vibrates, which powers the negative resistance circuit after passing through the energy harvesting circuit. The input end of the piezoelectric layer is connected to an external AC voltage source. During antenna transmission, the piezoelectric layer generates AC strain under AC voltage excitation and transmits it to the piezomagnetic thin film unit, causing magnetic moment oscillation. The composite beam converges the AC strain generated by the magnetoelectric transmitting array, regulates the oscillation of the permanent magnet, and modulates the static magnetic energy of the permanent magnet into an AC magnetic field.

2. The low-frequency multiferroic mechanical antenna amplified by a multifunctional metamaterial beam according to claim 1, characterized in that, The piezomagnetic thin film unit extends outward from the edge of the strong hysteresis piezomagnetic layer into four trapezoidal structures, with the narrow ends of the trapezoidal structures close to the edge of the strong hysteresis piezomagnetic layer.

3. The low-frequency multiferroic mechanical antenna amplified by a multifunctional metamaterial beam according to claim 1, characterized in that, The grid structure of the first elastic substrate is arranged in a grid pattern with horizontal and vertical inclinations, and the metal spiral structure is fixedly connected to the connecting beams between the intersections of the grid structure of the first elastic substrate.

4. The low-frequency multiferroic mechanical antenna with multifunctional metamaterial beam amplification according to claim 1, characterized in that, The piezomagnetic thin film unit and the piezoelectric layer are bonded to the composite beam.

5. The low-frequency multiferroic mechanical antenna amplified by a multifunctional metamaterial beam according to claim 1, characterized in that, The metal spiral structure is a square-shaped metal sheet.

6. The low-frequency multiferroic mechanical antenna with multifunctional metamaterial beam amplification according to claim 1, characterized in that, The thickness of the first elastic substrate and the second elastic substrate ranges from 0.1 mm to 2 mm.

7. The low-frequency multiferroic mechanical antenna with multifunctional metamaterial beam amplification according to claim 1, characterized in that, The piezoelectric layer is made of PZT or PMN-PT piezoelectric material.

8. The low-frequency multiferroic mechanical antenna with multifunctional metamaterial beam amplification according to claim 1, characterized in that, The thicknesses of the strong hysteresis piezomagnetic layer, the piezomagnetic thin film unit, and the piezoelectric layer range from 0.1 mm to 2 mm.

9. The low-frequency multiferroic mechanical antenna amplified by a multifunctional metamaterial beam according to claim 1, characterized in that, The thickness of the flexible piezoelectric PVDF layer ranges from 0.02 mm to 0.2 mm.

10. The low-frequency multiferroic mechanical antenna amplified by a multifunctional metamaterial beam according to claim 1, characterized in that, The input end of the piezoelectric layer is connected to an external AC voltage source. The AC voltage source excites the elastic standing wave generated by the piezoelectric layer array. The variable stiffness characteristics of the elastic substrate in the composite beam and the strain convergence characteristics of the spindle structure enhance the magnetic moment oscillation effect of the permanent magnet at the end of the beam. The vibration of the permanent magnet and the magnetostriction effect of the piezoelectric film together generate the emitted AC magnetic field. The piezoelectric layer array is composed of all the piezoelectric layers.

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