Very Low Frequency Multiferroic Mechanical Antenna with Non-Volatile Reconfigurable Frequency Bands and Radiation Patterns

Abstract

A Very-Low-Frequency Multiferroic Mechanical Antenna with Non-Volatile Reconfigurable Frequency Band and Radiation Pattern: The first multiferroic antenna is composed of multiple heterojunctions of soft magnetic thin film layers / high-quality factor piezoelectric layers / soft magnetic thin film layers and a substrate, and integrates the multiferroic heterojunction and planar inductor. On the one hand, the non-volatile electrically controlled inductor can maintain the adjustment of the antenna resonance frequency after power-off; on the other hand, by applying different electric fields to the antenna array, the regulation of the emission magnetic field intensity and radiation pattern can be realized. The second multiferroic mechanical antenna is composed of high-quality factor piezoelectric layers / soft magnetic thin film layers / strong hysteresis piezoelectric layers / soft magnetic thin film layers / high-quality factor piezoelectric layers. On the one hand, the non-volatile stress generated by exciting the strong hysteresis piezoelectric layer with an electric field pulse is used to regulate the easy axis direction of the magnetization intensity of the soft magnetic thin film layer, so as to maintain the regulation of the emission magnetic field direction after power-off; on the other hand, the strong hysteresis and high-quality factor piezoelectric layers are connected in series, and the non-volatile regulation of the frequency band is realized by using the non-volatile dielectric constant of the former.

Description

Technical Field

[0001] The present invention relates to a very low frequency antenna required for wireless communication in high-loss media (such as special environments like underground or underwater), and particularly to a very low frequency multiferroic mechanical antenna having a non-volatile reconfigurable frequency band and radiation pattern. Background Art

[0002] Radio frequency communication technologies such as Bluetooth and 5G are widely used in daily life. However, radio frequency communication in high-conductivity media such as underground and underwater will suffer severe path attenuation due to the strong skin effect, so it is not suitable for underground and underwater communication. Currently, countries around the world mainly build large-scale ultra-long wave transmitting stations to achieve wireless communication in land-based, underwater, and underground environments. However, at this time, the antenna is still an electrically small antenna compared to the very low frequency / ultra-low frequency wavelength, and the radiation efficiency is extremely low. Different from traditional electrically small antennas, mechanical antennas do not rely on electromagnetic oscillating currents to generate electromagnetic radiation, but use mechanical energy to drive the movement of charges and magnetic dipoles, thus breaking the correlation between the size of traditional antennas and electromagnetic wavelengths. The multiferroic mechanical antenna based on piezoelectric materials directly excites the piezoelectric layer with an alternating voltage near the electromechanical resonance frequency. Since the device is driven by sound waves with a shorter wavelength, it can reduce the size by 5 orders of magnitude compared with traditional low-frequency electrical antennas, which is conducive to the miniaturization of low-frequency antennas. Moreover, due to the good insulation of piezoelectric materials and the absence of the need for an external motor to rotate the antenna, the antenna power consumption is further reduced. However, after the device structure and installation orientation of the current multiferroic mechanical antenna are determined, it is difficult to adaptively adjust the working frequency band and the direction of the emitted magnetic field. Different loss media and communication scenarios often require adaptive adjustment of the working frequency band and the magnetic field emission direction without changing the antenna structure, so as to improve the communication performance in different environments. However, there is no relevant research and report in the field of mechanical antennas at present, which severely restricts the intelligent level of antennas.

[0003] Since the working principle of magnetoelectric antennas is mainly based on the magnetoelectric effect, and since reconfigurable antennas involve the adjustability of the magnetoelectric effect, the relevant research status is briefly introduced here. Currently, the research on the adjustability of the magnetoelectric effect mainly focuses on aspects such as adjusting the magneto-mechanical resonance frequency and the ferromagnetic resonance frequency. J. Zha of Virginia Tech in the United States regulated Terfenol-D / Pb(Zr x Ti 1-x )O 3The Young's modulus of the piezomagnetic layer in the laminate, enabling the adjustment of the resonant frequency in the range of 40 kHz - 55 kHz. C. Park in the United States and M. Bichurin of the Institute of Electronic and Information Systems in Russia et al. studied the piezoelectric / piezomagnetic laminate with a shape gradient change. Utilizing the multimodal vibration characteristics of the shaped laminate, a magnetoelectric coefficient of 3000 mV / cm·Oe can be provided within a bias magnetic field of 52 Oe - 242 Oe, and the working frequency band is broadened. J. Gao et al. in the United States changed the bending resonant frequency by adding mass blocks with different weights at both ends of the laminate, thus adjusting the resonant frequency from 70 Hz to 220 Hz. L. Niu et al. of the Institute of Engineering Physics, Chinese Academy of Sciences, produced a bimodal effect in the piezomagnetic / piezoelectric laminate by adjusting the direction of the bias magnetic field. However, the method of applying a bias magnetic field currently used to adjust the resonant frequency of the magnetoelectric laminate significantly increases the power consumption of the device, while the frequency shift ranges of methods such as adjusting the prestress, adding mechanical loads, and shaped design are small, and it is difficult to achieve continuous frequency shift adjustment of the antenna array without changing the antenna structure. In addition, no researcher has reported the adaptive control of the emission magnetic field direction without changing the structure and orientation of the magnetoelectric mechanical antenna, which severely limits the adaptability of the magnetoelectric antenna to various environments. 3 By adding mass blocks with different weights at both ends of the laminate to change the bending resonant frequency, the resonant frequency is adjusted from 70 Hz to 220 Hz. L. Niu et al. of the Institute of Engineering Physics, Chinese Academy of Sciences, produced a bimodal effect in the piezomagnetic / piezoelectric laminate by adjusting the direction of the bias magnetic field. However, the method of applying a bias magnetic field currently used to adjust the resonant frequency of the magnetoelectric laminate significantly increases the power consumption of the device, while the frequency shift ranges of methods such as adjusting the prestress, adding mechanical loads, and shaped design are small, and it is difficult to achieve continuous frequency shift adjustment of the antenna array without changing the antenna structure. In addition, no researcher has reported the adaptive control of the emission magnetic field direction without changing the structure and orientation of the magnetoelectric mechanical antenna, which severely limits the adaptability of the magnetoelectric antenna to various environments. Summary of the Invention

[0004] Aiming at the problems in the background technology, the present invention proposes a very low frequency multiferroic mechanical antenna with a non-volatile reconfigurable frequency band and radiation pattern, which can arbitrarily control the working frequency band and the magnetic field emission direction of the antenna without changing the antenna structure, and the control effect can still be maintained after power-off.

[0005] On the one hand, the present invention provides a very low frequency multiferroic mechanical antenna (Structure 1) with a non-volatile reconfigurable frequency band and radiation pattern, characterized in that it includes a substrate, a plurality of multiferroic heterojunctions arranged in an array on the substrate, and a planar inductor;

[0006] The multiferroic heterojunction includes a piezoelectric layer, an upper soft magnetic thin strip layer and a lower soft magnetic thin strip layer respectively fixed on the upper and lower surfaces of the piezoelectric layer;

[0007] The planar inductor includes, from top to bottom, an upper strong hysteresis piezoelectric layer, a first soft magnetic thin strip layer, a planar coil, a second soft magnetic thin strip layer and a lower strong hysteresis piezoelectric layer;

[0008] The piezoelectric layer is connected to the planar coil, the upper strong hysteresis piezoelectric layer and the lower strong hysteresis piezoelectric layer are externally connected to a pulse power supply, and the piezoelectric layer is externally connected to an AC high voltage power supply.

[0009] Furthermore, the piezoelectric layer has a high quality factor, and its quality factor can reach 800 - 2000.

[0010] Furthermore, when the operating frequency band of the non-volatile tunable multiferroic antenna is adjusted, a pulsed power supply is used to excite the strong hysteresis piezoelectric layer of the planar inductor, and the non-volatile stress generated by it is used to adjust the inductor. Then, an AC high-voltage power supply is used to excite the piezoelectric layer in the multiferroic heterojunction to generate an AC stress, which causes the magnetic moment oscillation and magnetic field emission of the soft magnetic thin strip layer, changing the operating frequency band. When the radiation pattern of the antenna's emitted magnetic field is adjusted, by applying electric fields with different magnitudes and phases to multiple multiferroic heterojunctions in the antenna array, the tilting direction of the magnetic moment of the soft magnetic thin strip layer is jointly adjusted by sound waves and magnetic fields with different directions and intensities in the two-dimensional plane, so as to adjust the radiation pattern of the emitted magnetic field through the superposition of the magnetic field beam vectors of multiple multiferroic heterojunctions.

[0011] On the other hand, the present invention also provides a very low frequency multiferroic mechanical antenna (Structure 1) with non-volatile reconfigurable frequency band and radiation pattern, which is characterized by including a substrate and a multiferroic heterojunction; the multiferroic heterojunction includes, from top to bottom, a first high-quality factor piezoelectric layer, an upper high-permeability soft magnetic thin strip layer, a strong hysteresis piezoelectric layer, a lower high-permeability soft magnetic thin strip layer, and a second high-quality factor piezoelectric layer; the strong hysteresis piezoelectric layer is externally connected to a pulsed power supply, and the first high-quality factor piezoelectric layer is externally connected to an AC high-voltage power supply.

[0012] Furthermore, when non-volatile adjustment of the operating frequency band of the multiferroic antenna is carried out, first, the strong hysteresis piezoelectric layer and the high-quality factor piezoelectric layer are connected, and a pulsed power supply is used to excite the strong hysteresis piezoelectric layer, causing non-volatile changes in the dielectric constant and equivalent capacitance; then, when transmitting information, an AC high-voltage power supply is used to excite the circuit formed by the high-quality factor piezoelectric layer and the strong hysteresis piezoelectric layer, and the non-volatile change in the equivalent impedance of the circuit is used to adjust the magneto-mechanical resonance frequency and the operating frequency band of the antenna; when non-volatile adjustment of the direction of the magnetic field emitted by the multiferroic antenna is carried out, the connection between the strong hysteresis piezoelectric layer and the high-quality factor piezoelectric layer is disconnected. First, the non-volatile stress generated by exciting the strong hysteresis piezoelectric layer with a pulsed power supply is used to adjust the easy axis direction of the magnetic moment of the soft magnetic thin strip, and then, when transmitting information, an AC high-voltage power supply is used to excite the high-quality factor piezoelectric layer to generate an AC stress, which is transmitted to the soft magnetic thin strip and causes the magnetic moment to oscillate near the equilibrium position, so that the antenna emits a magnetic field along the easy axis direction of the magnetic moment.

[0013] The beneficial technical effects of the present invention are as follows:

[0014] (1) The optimal frequencies for implementing wireless communication in different high-loss communication scenarios (underground and underwater) are different. Without changing the mechanical antenna structure, Structure 1 and Structure 2 respectively utilize the non-volatile planar inductor and the non-volatile capacitance of the strong hysteresis piezoelectric layer to achieve arbitrary regulation of the magneto-mechanical resonance frequency and the working frequency band of the antenna, enhancing the adaptability of the antenna to different communication scenarios. At the same time, the non-volatile regulation function of the multiferroic antenna in the present invention enables the regulation ability of the working frequency band to be maintained even after power-off, significantly reducing the regulation power consumption of the working frequency band compared with existing regulation technologies such as varactor diodes.

[0015] (2) Without changing the mechanical antenna structure, Structure 1 and Structure 2 respectively utilize the magnetic field beam shaping ability of the multiferroic antenna array and the regulation ability of the strong hysteresis piezoelectric layer on the easy axis of the magnetic moment of the soft magnetic thin strip to achieve arbitrary regulation of the radiation magnetic field pattern, so as to be able to achieve the adaptive regulation function when the relative position of the receiving party changes, significantly improving the intelligent level of the magnetoelectric antenna. Description of the Drawings

[0016] Figure 1 is a schematic diagram of Embodiment 1 of the very low frequency multiferroic mechanical antenna with non-volatile reconfigurable frequency band and pattern of the present invention.

[0017] Figure 2 is the equivalent circuit schematic diagram of Embodiment 1 of the very low frequency multiferroic mechanical antenna of the present invention.

[0018] Figure 3 is a schematic diagram of Embodiment 2 of the very low frequency multiferroic mechanical antenna with non-volatile reconfigurable frequency band and pattern of the present invention.

[0019] Figure 4 is the equivalent circuit schematic diagram of Embodiment 2 of the very low frequency multiferroic mechanical antenna of the present invention.

[0020] In the figure: 1-1 - upper soft magnetic thin strip layer; 2 - upper high-quality piezoelectric layer; 1-2 - lower soft magnetic thin strip layer; 3 - substrate; 4-1 - upper strong hysteresis piezoelectric layer; 5-1 - first soft magnetic thin strip layer; 6 - planar coil; 4-2 - lower strong hysteresis piezoelectric layer; 5-2 - second soft magnetic thin strip layer; 7 - pulse power supply; 8 - AC high voltage source; 9-1 - switch; 9-2 - switch; 10 - electrode resistance of the high-quality piezoelectric layer; 11 - dynamic resistance of the high-quality piezoelectric layer; 12 - dynamic capacitance of the high-quality piezoelectric layer; 13 - dynamic inductance of the high-quality piezoelectric layer; 14 - dielectric loss resistance of the high-quality piezoelectric layer; 15 - static capacitance of the high-quality piezoelectric layer; 16 - equivalent inductance of the planar coil.

[0021] 17-1 - The first high-quality factor piezoelectric layer; 18-1 - The upper high-permeability soft magnetic thin strip layer; 19 - The strong hysteresis piezoelectric layer; 18-2 - The lower high-permeability soft magnetic thin strip layer; 17-2 - The second high-quality factor piezoelectric layer; 20 - The pulse power supply; 21 - The AC high-voltage source; 22-1 - The switch; 22-1 - The switch; 22-3 - The switch; 22-4 - The switch; 23-1 - The electrode resistance of the strong hysteresis piezoelectric layer; 24-1 - The dynamic resistance of the strong hysteresis piezoelectric layer; 25-1 - The dynamic capacitance of the strong hysteresis piezoelectric layer; 26-1 - The dynamic inductance of the strong hysteresis piezoelectric layer; 27-1 - The dielectric loss resistance of the strong hysteresis piezoelectric layer; 28-1 - The static capacitance of the strong hysteresis piezoelectric layer; 22-2 - The electrode resistance of the high-quality factor piezoelectric layer; 24-2 - The dynamic resistance of the high-quality factor piezoelectric layer; 25-2 - The dynamic capacitance of the high-quality factor piezoelectric layer; 26-2 - The dynamic inductance of the high-quality factor piezoelectric layer; 27-2 - The dielectric loss resistance of the high-quality factor piezoelectric layer; 28-2 - The static capacitance of the high-quality factor piezoelectric layer. Detailed implementation mode

[0022] The present invention will be further described below in conjunction with specific embodiments and the drawings, but the protection scope of the present invention should not be limited thereby.

[0023] First, please refer to Figure 1 , Figure 1 FIG. is a very low frequency multiferroic mechanical antenna (Structure 1) with non-volatile reconfigurable frequency band and radiation pattern of the present invention, including a multiferroic antenna array and a planar inductor. The multiferroic antenna array includes soft magnetic thin strip layers 1-1 and 1-2; a high-quality factor piezoelectric layer 2; and a substrate 3. The upper and lower electrodes of the high-quality factor piezoelectric layer 2 in the multiferroic antenna are connected to both ends of the AC high-voltage source 8 through the switch 9-2, and the AC high-voltage source 8 is used to realize magnetic field emission and the regulation of the radiation pattern of the emitted magnetic field. The planar inductor includes soft magnetic thin strip layers 5-1 and 5-2; a planar coil 6; and strong hysteresis piezoelectric layers 4-1 and 4-2. The planar coil 6 is connected in series with the high-quality factor piezoelectric layer 2 of the multiferroic antenna through a wire. The upper and lower electrodes of the strong hysteresis piezoelectric layers 4-1 and 4-2 in the planar inductor are connected to both ends of the pulse power supply 7 through the switch 9-1, and the pulse power supply 7 is used to realize non-volatile regulation of the planar inductor.

[0024] Please refer to Figure 2 for the equivalent circuit diagram of the very low frequency multiferroic mechanical antenna (Structure 1). The non-volatile regulation working process of the multiferroic mechanical antenna (Structure 1) is as follows: Please refer to Figure 1 . First, the strong hysteresis piezoelectric layers 4-1 and 4-2 of the planar inductor are excited by the pulse power supply 7 through the switch 9-1, and the non-volatile stress generated by the strong hysteresis piezoelectric layers 4-1 and 4-2 is used to realize the regulation of the planar inductor. Refer to Figure 2The equivalent inductance of the planar coil is 16; then, an AC high-voltage power supply 8 is used to excite the high-quality-factor piezoelectric layer 2 in the multiferroic heterostructure to generate an AC stress, causing the magnetic moment oscillation of the soft magnetic thin strip layers 1-1 and 1-2, thereby realizing magnetic field emission; here, the planar coil 6 in the planar inductor is connected in series with the high-quality-factor piezoelectric layer 2 of the multiferroic antenna through a wire, and the planar inductor is regulated by a pulse power supply 7 to change the resonance frequency and working frequency band of the multiferroic mechanical antenna (structure 1). The regulation process of the emission magnetic field pattern of the multiferroic mechanical antenna (structure 1) is as follows: Different amplitudes and phases of electric fields are generated by the AC high-voltage power supply 8 to excite the multiple high-quality-factor piezoelectric layers 2 in the antenna array, and the deflection directions of the magnetic moments of the soft magnetic thin strip layers 1-1 and 1-2 are jointly regulated by the acoustic waves and magnetic fields with different directions and intensities in the two-dimensional plane, so as to realize the regulation of the emission magnetic field pattern through the superposition of the magnetic field beam vectors of multiple multiferroic heterojunctions.

[0025] Structure 1 is a mechanical antenna array composed of multiple multiferroic heterojunction antennas, a substrate, and a planar inductor. The multiferroic heterojunction is composed of multiple soft magnetic thin strip layer / high-quality-factor piezoelectric layer / soft magnetic thin strip layer units. The planar inductor is composed of a strong hysteresis piezoelectric layer / soft magnetic thin strip layer / planar coil / soft magnetic thin strip layer / strong hysteresis piezoelectric layer. Here, the piezoelectric layer of the multiferroic heterojunction is connected to the planar coil of the planar inductor. Structure 2 is composed of a high-quality-factor piezoelectric layer / soft magnetic thin strip layer / strong hysteresis piezoelectric layer / soft magnetic thin strip layer / high-quality-factor piezoelectric layer. When regulating the working frequency band and magnetic field emission direction, the high-quality-factor piezoelectric layer and the strong hysteresis piezoelectric layer are respectively connected and disconnected.

[0026] For structure 1, when non-volatilely regulating the working frequency band of the antenna: on the one hand, due to the non-monotonic characteristic of the equivalent capacitance of the multiferroic antenna near the resonance frequency, multiple LC resonance peaks can be generated after the cascade of the multiferroic antenna and the planar inductor, increasing the bandwidth; on the other hand, an electric field pulse is used to excite the piezoelectric layer with a specific tangential direction in the planar inductor, and the non-volatile strain (stress) generated by the non-180° ferroelectric domain rotation during the depolarization process is transmitted to the adjacent soft magnetic thin strip, realizing the non-volatile regulation of the magnetic permeability and inductance value of the soft magnetic thin strip, and thus still being able to maintain the adjustment of the magneto-mechanical resonance frequency and the antenna working frequency band after power-off. When regulating the magnetic field emission direction, the relationship between the magnetic field intensity and direction generated by the emission antenna array composed of two-dimensional multiferroic units and the amplitude and phase of the electric field applied to each multiferroic unit is studied using the magneto-mechanical equivalent circuit and Maxwell's theory, and the electric field excitation required to achieve a specific magnetic field emission direction is inversely obtained using an optimization algorithm. Specifically, by applying corresponding electric field excitations to the multiferroic units distributed in different directions in the array, the deflection directions of the magnetic moments of the piezomagnetic units are jointly regulated by the elastic energy and magnetic field energy with different directions and intensities in the two-dimensional plane, so as to finally realize the regulation of the emission magnetic field intensity and direction through the superposition of the magnetic field beam vectors of multiple multiferroic units.

[0027] Please first refer to Figure 3 , Figure 3 which is a very low frequency multiferroic mechanical antenna (Structure 2) with non-volatile reconfigurable frequency band and radiation pattern, including high quality factor piezoelectric layers 17-1 and 17-2, high magnetic permeability soft magnetic thin strip layers 18-1 and 18-2, and a strong hysteresis piezoelectric layer 19. The upper and lower electrodes of the strong hysteresis piezoelectric layer 19 are connected to a pulse power supply 20 through a switch 22-2, and the pulse power supply 20 excites the strong hysteresis piezoelectric layer 19 to cause non-volatile changes in the dielectric constant and equivalent capacitance. The upper and lower electrodes of the high quality factor piezoelectric layers 17-1 and 17-2 of the multiferroic mechanical antenna are connected to an AC high voltage source 21 through a switch 22-1, and the AC high voltage source 21 is used to achieve magnetic field emission. The high quality factor piezoelectric layers 17-1 and 17-2 and the strong hysteresis piezoelectric layer 19 are connected in series through switches 22-3 and 22-4.

[0028] Please refer to Figure 3 for the equivalent circuit diagram of the very low frequency multiferroic mechanical antenna (Structure 2) with non-volatile reconfigurable frequency band and radiation pattern. The non-volatile reconfigurable frequency band process of the very low frequency multiferroic mechanical antenna (Structure 2) is as follows: Please refer to Figure 3 . The pulse power supply 20 excites the strong hysteresis piezoelectric layer 19, and after causing non-volatile changes in the dielectric constant and equivalent capacitance of the strong hysteresis piezoelectric layer 19, the switch 22-2 is disconnected. Refer to Figure 4 for the static capacitance 28-1 of the strong hysteresis piezoelectric layer in , and then the strong hysteresis piezoelectric layer 19 and the high quality factor piezoelectric layers 17-1 and 17-2 are connected in series through switches 22-3 and 22-4; then the AC high voltage source 21 is connected to the high quality factor piezoelectric layers 17-1 and 17-2 and the strong hysteresis piezoelectric layer 19 through the switch 22-1, and the non-volatile changes in the equivalent impedance of the high quality factor piezoelectric layers 17-1 and 17-2 and the strong hysteresis piezoelectric layer 19 are utilized to achieve non-volatile regulation of the magneto-mechanical resonance frequency and the antenna operating frequency band. The non-volatile reconfigurable radiation magnetic field direction process of the very low frequency multiferroic mechanical antenna (Structure 2) is as follows: The pulse power supply 20 excites the strong hysteresis piezoelectric layer 19, causing non-volatile stress to regulate the easy axis direction of the magnetic moments of the high magnetic permeability soft magnetic thin strips 18-1 and 18-2; the AC high voltage source 21 is connected to the high quality factor piezoelectric layers 17-1 and 17-2 through the switch 22-1, and the AC stress generated by the high quality factor piezoelectric layers 17-1 and 17-2 is transmitted to the high magnetic permeability soft magnetic thin strips 18-1 and 18-2, causing the magnetic moments to oscillate near the easy axis position, so that the antenna emits a magnetic field along the easy axis direction.

[0029] For Structure 2, the strong hysteresis piezoelectric layer mainly realizes the non-volatile regulation function, while the high-quality factor piezoelectric layer mainly realizes the AC driving function. When regulating the working frequency band of the non-volatile regulation antenna: the strong hysteresis piezoelectric layer and the high-quality factor piezoelectric layer are connected in series, and the strong hysteresis piezoelectric layer is excited by a pulsed electric field to generate non-180° ferroelectric domain rotation, so that the dielectric constant and the equivalent capacitance have non-volatile changes after power-off. Since the strong hysteresis piezoelectric layer and the high-quality factor piezoelectric layer are connected in series, this causes changes in the equivalent capacitance and the magneto-mechanical resonance frequency of the entire driving circuit. When transmitting information, the series circuit is excited by an AC high-voltage source, so as to realize the regulation of the magneto-mechanical resonance frequency and the antenna working frequency band by using the non-volatile change of the loop equivalent impedance; when regulating the emission magnetic field direction of the multiferroic antenna, the connection between the strong hysteresis piezoelectric layer and the high-quality piezoelectric layer is disconnected, and the strong hysteresis piezoelectric layer is excited by a pulsed power supply to generate non-volatile stress, and the magnetic domain rotation and the change of the magnetic moment easy axis of the soft magnetic thin strip are caused by the magneto-elastic energy. Then, the high-quality factor piezoelectric layer is excited by an AC high-voltage source to generate AC strain, which causes the magnetic moment of the soft magnetic thin strip to oscillate at the equilibrium position, thereby generating an emission magnetic field along the easy axis direction, realizing the non-volatile regulation of the magnetic field emission pattern.

Claims

1. A very low frequency multiferroic mechanical antenna with non-volatile reconfigurable frequency band and radiation pattern, Characterized in that, it includes a substrate, a plurality of multiferroic heterojunctions arranged in an array on the substrate, and a planar inductor; The multiferroic heterojunction includes a piezoelectric layer (2), an upper soft magnetic thin strip layer (1-1) and a lower soft magnetic thin strip layer (1-2) respectively fixed on the upper and lower surfaces of the piezoelectric layer (2); The planar inductor includes, from top to bottom, an upper strong hysteresis piezoelectric layer (4-1), a first soft magnetic thin strip layer (5-1), a planar coil (6), a second soft magnetic thin strip layer (5-2) and a lower strong hysteresis piezoelectric layer (4-2); The piezoelectric layer (2) is connected to the planar coil (6), the upper strong hysteresis piezoelectric layer (4-1) and the lower strong hysteresis piezoelectric layer (4-2) are externally connected to a pulse power supply (7), and the piezoelectric layer (2) is externally connected to an AC high voltage power supply (8); When non-volatilely regulating the operating frequency band of the multiferroic antenna, the upper strong hysteresis piezoelectric layer (4-1) and the lower strong hysteresis piezoelectric layer (4-2) of the planar inductor are excited by the pulse power supply (7), and the non-volatile stress generated by them is used to realize the regulation of the planar inductor. Then, the piezoelectric layer (2) in the multiferroic heterojunction is excited by the AC high voltage power supply (8) to generate an AC stress, which causes the magnetic moment oscillation and magnetic field emission of the upper soft magnetic thin strip layer (1-1) and the lower soft magnetic thin strip layer (1-2), so that the operating frequency band changes; when regulating the radiation pattern of the antenna to emit a magnetic field, by applying electric fields with different magnitudes and phases to a plurality of multiferroic heterojunctions in the antenna array, the tilting direction of the magnetic moment of the soft magnetic thin strip layer is jointly regulated by sound waves and magnetic fields with different directions and intensities in the two-dimensional plane, so as to realize the regulation of the radiation pattern of the emitted magnetic field through the superposition of the magnetic field beam vectors of a plurality of multiferroic heterojunctions.

2. The very low frequency multiferroic mechanical antenna with non-volatile reconfigurable frequency band and radiation pattern according to claim 1, Characterized in that, The piezoelectric layer (2) has a high quality factor, and its quality factor is between 800 and 2000.

3. A very low frequency multiferroic mechanical antenna with non-volatile reconfigurable frequency band and radiation pattern, Characterized in that, it includes a substrate, a plurality of multiferroic heterojunctions arranged in an array on the substrate; the multiferroic heterojunction includes, from top to bottom, a first high-quality factor piezoelectric layer (17-1), an upper high magnetic permeability soft magnetic thin strip layer (18-1), a strong hysteresis piezoelectric layer (19), a lower high magnetic permeability soft magnetic thin strip layer (18-2) and a second high-quality factor piezoelectric layer (17-2); the strong hysteresis piezoelectric layer (19) is externally connected to a pulse power supply (20), and the first high-quality factor piezoelectric layer (17-1) is externally connected to an AC high voltage power supply (20); When non-volatile regulation is performed on the working frequency band of the multiferroic antenna, first connect the strong hysteresis piezoelectric layer (19) to the first high-quality factor piezoelectric layer (17-1) and the second high-quality factor piezoelectric layer (17-2). Use the pulsed power supply (20) to excite the strong hysteresis piezoelectric layer (19) and cause non-volatile changes in the dielectric constant and equivalent capacitance. Then, when transmitting information, use the AC high-voltage source (21) to excite the loop formed by the first high-quality factor piezoelectric layer (17-1), the second high-quality factor piezoelectric layer (17-2), and the strong hysteresis piezoelectric layer (19), and use the non-volatile change in the loop equivalent impedance to achieve the regulation of the magneto-mechanical resonance frequency and the antenna working frequency band. When non-volatile regulation is performed on the magnetic field emission direction of the multiferroic antenna, disconnect the connection between the strong hysteresis piezoelectric layer (19) and the first high-quality factor piezoelectric layer (17-1) and the second high-quality factor piezoelectric layer (17-2). First, use the non-volatile stress generated by exciting the strong hysteresis piezoelectric layer (19) with the pulsed power supply (20) to regulate the easy axis direction of the magnetic moments of the upper high-permeability soft magnetic thin strip layer (18-1) and the lower high-permeability soft magnetic thin strip layer (18-2). Then, when transmitting information, use the AC high-voltage source (21) to excite the first high-quality factor piezoelectric layer (17-1) and the second high-quality factor piezoelectric layer (17-2) to generate AC stress, which is transmitted to the upper high-permeability soft magnetic thin strip layer (18-1) and the lower high-permeability soft magnetic thin strip layer (18-2), and causes the magnetic moments to oscillate near the equilibrium position, so that the antenna emits a magnetic field along the easy axis direction of the magnetic moments.

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