Cross-medium communication system and method based on magnetoelectric mechanical antenna and vibration / voltage in-situ synchronous measurement system and method

Abstract

The invention belongs to the technical field of long-wave communication and electronic information, and discloses a cross-medium communication system based on a magnetoelectric mechanical antenna, which comprises the magnetoelectric mechanical antenna, a receiving coil, a transmission medium container, a signal generator, a power amplifier and a static bias magnetic field applying device, the magnetoelectric mechanical antenna is arranged on a support of the static bias magnetic field applying device, the receiving coil is arranged in the transmission medium container, and the main vibration direction of the receiving coil and the main vibration direction of the magnetoelectric mechanical antenna are coaxial; the signal generator is connected with the power amplifier in series, the power amplifier is connected with a lead-out wire of a piezoelectric layer of the magnetoelectric mechanical antenna, and the signal generator provides an excitation signal for the piezoelectric layer of the magnetoelectric mechanical antenna through the power amplifier; and the digital oscilloscope is connected with the port of the receiving coil and is used for collecting electromagnetic wave signals which are captured by the receiving coil and are transmitted by the magnetoelectric mechanical antenna. The cross-medium communication system provided by the invention can realize effective and stable transmission of information among different media.

Description

Technical Field

[0001] The present invention belongs to the field of long-wave communication and electronic information technology, and specifically relates to a cross-medium communication system and method based on a magneto-electro-mechanical antenna, and an in-situ synchronous vibration / voltage measurement system and method of the magneto-electro-mechanical antenna. Background Art

[0002] Mechanical antennas are a new type of low-frequency transmitting antenna that generates electromagnetic field radiation through the mechanical motion of electric charges or magnetic dipoles. Currently, mechanical antennas are broadly categorized into four types based on their implementation: electret, permanent magnet, piezoelectric, and magnetoelectric. The high-frequency electromagnetic waves emitted by traditional magnetoelectric antennas are severely attenuated in media such as seawater and soil. In practical applications, permanent magnet mechanical antenna cross-medium communication technology faces challenges such as high energy consumption, unstable signals, and low transmission efficiency.

[0003] Magnetoelectric mechanical antennas consist of a magnetostrictive material layer and a piezoelectric material layer. They utilize the magneto-mechanical-electrical coupling effect of a magnetoelectric heterostructure to transmit (inverse magneto-electrical coupling) and receive (positive magneto-electrical coupling) electromagnetic waves. This process is enhanced by enhancing acoustic resonance. When voltage is applied to the piezoelectric layer, strain is transferred to the magnetostrictive layer via the inverse piezoelectric effect, causing magnetization oscillations and magnetic moment reversal, generating radiated electromagnetic waves. When the alternating magnetic field component of the electromagnetic wave signal acts on the magnetostrictive layer, strain is also transferred to the piezoelectric layer, enabling electromagnetic wave reception. The piezoelectric layer then induces corresponding charges on the electrode surfaces on both sides of the piezoelectric layer through the positive piezoelectric effect, which are detected by a detector. This electrical-mechanical-magnetic energy coupling method can reduce the size of mechanical antennas to one-tenth or even one-hundredth of that of traditional antennas without changing the antenna's operating frequency. By leveraging the fact that the speed of acoustic waves generated by mechanical vibration is slower than that of electromagnetic waves (approximately 4-5 orders of magnitude slower), the size of the mechanical antenna can be reduced to one-tenth or even one-hundredth that of conventional antennas.

[0004] In addition, the vibration characteristics of magnetoelectric mechanical antennas directly affect mechanical stability and electromagnetic radiation efficiency. By measuring vibration velocity, potential structural defects such as abnormal resonance frequency and amplitude can be identified, preventing component wear or breakage due to long-term vibration, and ensuring the reliable operation of the antenna in complex environments. Measuring the response voltage can reflect the electromagnetic conversion efficiency (such as the conversion rate of mechanical energy to electromagnetic energy), evaluate the antenna's signal transmission / reception capabilities under dynamic vibration, and ensure communication quality. Traditional measurement methods require the separate use of a laser vibrometer (to measure vibration) and an induction coil (to measure voltage), resulting in a temporal and spatial asynchrony between the vibration velocity and the magnetic field signal. Separate measurements require multiple positioning and data fusion, which is time-consuming and difficult to support real-time monitoring and control needs. The operation is complex and inefficient.

[0005] Therefore, there is an urgent need for an efficient and stable cross-medium communication method and a method that can simultaneously measure the vibration velocity and induced magnetic field of the mechanical antenna. Summary of the Invention

[0006] The present invention addresses the problems of unstable signals and low efficiency in cross-medium communication and the technical problem that existing measurement methods cannot simultaneously measure the vibration velocity and induced magnetic field of magneto-electro-mechanical antennas. The present invention provides a cross-medium communication system based on magneto-electro-mechanical antennas to achieve effective and stable transmission of information between different media. In addition, the present invention provides an in-situ synchronous measurement system for the vibration / voltage signals of magneto-electro-mechanical antennas, which deeply integrates the vibration-voltage dual dynamic response with the phase-locked amplification technology to simultaneously obtain the response voltage signal and the vibration velocity signal, thus solving the problem of low measurement efficiency and data asynchrony caused by the need to move the sample in the traditional method.

[0007] To achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a cross-medium communication system based on a magneto-electro-mechanical antenna, comprising a magneto-electro-mechanical antenna, a receiving coil, a transmission medium container, a signal generator, a power amplifier, and a static bias magnetic field application device. The magneto-electro-mechanical antenna is a symmetrical structure consisting of a piezoelectric layer and two magnetostrictive layers placed on either side of the piezoelectric layer. The magneto-electro-mechanical antenna is placed on a bracket of the static bias magnetic field application device, and the receiving coil is placed in the transmission medium container, with the receiving coil and the main vibration direction of the magneto-electro-mechanical antenna being coaxial. The signal generator is connected in series with a power amplifier, the power amplifier is connected to a lead wire of the piezoelectric layer of the magneto-electro-mechanical antenna, and the signal generator provides an excitation signal to the piezoelectric layer of the magneto-electro-mechanical antenna through the power amplifier; The digital oscilloscope is connected to the receiving coil port and is used to collect the electromagnetic wave signal emitted by the magneto-electromechanical antenna captured by the receiving coil.

[0008] In one technical solution, the magnetostrictive layer is an iron-nickel-chromium alloy, and the piezoelectric layer is PZT-8.

[0009] In one technical solution, the static bias magnetic field applying device is composed of NdFeB permanent magnets relatively arranged on the guide rail, providing a static bias magnetic field for the magneto-electromechanical antenna.

[0010] In one technical solution, the transmission medium in the transmission medium holding container is water, soil or sand.

[0011] In one technical solution, the cross-media communication system further includes a PC, which is loaded with Origin software to demodulate the received signal.

[0012] In a second aspect, the present invention provides a cross-medium communication method based on a magneto-electromechanical antenna, comprising the following steps: a. Place the magneto-electro-mechanical antenna on a bracket of a static bias magnetic field application device, and place the receiving coil in a transmission medium container, with the receiving coil coaxial with the main vibration direction of the magneto-electro-mechanical antenna; b. Turn on the signal generator and connect the modulated signal to the piezoelectric layer of the magneto-electromechanical antenna through the power amplifier; c. The receiving coil captures the electromagnetic wave signal emitted by the magneto-electromechanical antenna and transmits the voltage signal to a digital oscilloscope. The received signal is demodulated by the PC Origin software to achieve cross-media communication.

[0013] The cross-medium communication method of the present invention utilizes a magneto-electromechanical antenna to generate electromagnetic waves in one medium (such as air) through the inverse magnetostrictive effect, captures the signal through a receiving coil in another medium (such as water) and transmits it to a phase-locked amplifier for demodulation, thereby achieving effective and stable transmission of information between different media.

[0014] In a third aspect, the present invention provides an in-situ synchronous measurement system for vibration / voltage signals of a magneto-electro-mechanical antenna in a cross-medium communication system based on the magneto-electro-mechanical antenna, comprising a magneto-electro-mechanical antenna, a receiving coil, a static bias magnetic field applying device, a Doppler vibrometer, a lock-in amplifier, and a personal computer. The lead wire from the piezoelectric layer of the magneto-electro-mechanical antenna is connected to the voltage output end of the phase-locked amplifier, the receiving coil port is connected to the voltage input end I of the phase-locked amplifier, the voltage output end of the built-in velocity decoder of the Doppler vibrometer is connected to the voltage input end II of the phase-locked amplifier, and the phase-locked amplifier is connected to a personal computer via a communication cable; the magneto-electro-mechanical antenna is fixed on the middle bracket of the static bias magnetic field applying device; the personal computer adjusts the input voltage of the phase-locked amplifier to the piezoelectric layer of the magneto-electro-mechanical antenna and the bias magnetic field size applied by the static bias magnetic field applying device through a program.

[0015] In a fourth aspect, the present invention provides a vibration / voltage signal in-situ synchronous measurement method of the above-mentioned vibration / voltage signal in-situ synchronous measurement system, comprising the following steps: a. Place the magneto-electromechanical antenna on the central axis of the receiving coil and fix it to the center of the bracket; b. adjusting the input voltage of the lock-in amplifier to the piezoelectric layer of the magneto-electromechanical antenna and the magnitude of the bias magnetic field applied by the static bias magnetic field applying device through a program; e. Start the Doppler vibrometer, so that the laser beam passes through the focusing hole of the static bias magnetic field application device and focuses on the center position of the end face of the piezoelectric layer of the magneto-electromechanical antenna with a reflective film; d. The vibration velocity signal of the end face of the piezoelectric layer of the magneto-electromechanical antenna is converted into a voltage signal by the velocity decoder built into the Doppler vibrometer, transmitted to the PC via a lock-in amplifier, and then converted into vibration velocity according to the voltage-velocity conversion formula; e. The receiving coil captures the electromagnetic wave signal emitted by the magneto-electromechanical antenna and transmits the voltage signal to the lock-in amplifier.

[0016] The in-situ synchronous measurement method of the present invention applies voltage excitation to the piezoelectric layer of the magneto-electro-mechanical antenna through a lock-in amplifier. The polarized helium-neon beam emitted by the laser of the laser Doppler vibrometer is focused onto the center of the end face of the piezoelectric layer of the magneto-electro-mechanical antenna. The system sensor collects the reflected light with a frequency shift caused by the vibration of the piezoelectric layer and compares it with a reference light. The built-in velocity decoder then transmits the vibration velocity signal of the piezoelectric layer to the lock-in amplifier. The signal is then transmitted to a personal computer via the lock-in amplifier and reconverted into vibration velocity according to a voltage-to-velocity conversion formula. Simultaneously, a receiving coil outside the antenna captures the induced magnetic field generated by the magneto-electro-mechanical antenna and transmits the voltage signal to the same lock-in amplifier. The personal computer simultaneously displays the vibration velocity and magnetic field intensity. In this way, the vibration velocity signal and magnetic field voltage signal of the magneto-electro-mechanical antenna can be simultaneously acquired using the same lock-in amplifier without moving the magneto-electro-mechanical antenna.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The present invention is based on a cross-medium communication method using a magneto-electro-mechanical antenna. It uses the inverse magnetostrictive effect of a magneto-electro-mechanical antenna to generate electromagnetic waves in one medium (such as air). The signal is captured by a receiving coil in another medium (such as water) and transmitted to a phase-locked amplifier for demodulation, thereby achieving effective and stable transmission of information between different media, improving the reliability of underwater communication. It has the characteristics of simple structure, high efficiency and easy implementation, and can be widely used in long-wave communication fields such as ocean exploration, wireless power supply for underwater equipment and complex medium environment monitoring.

[0018] The present invention is based on the in-situ synchronous measurement method of vibration / voltage signals of magneto-electromechanical antennas, deeply integrating the vibration-voltage dual dynamic response with the phase-locked amplification technology, solving the problem of low measurement efficiency and data asynchrony caused by the need to move samples in traditional methods. The response voltage signal can be used to evaluate antenna performance while obtaining the vibration velocity signal, further returning to the underlying physical essence of the "mechanical" antenna, and realizing non-contact, non-destructive synchronous acquisition of optical and electrical dynamic response signals, which is easy to operate and highly efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram and communication data of the cross-medium (air-water) communication system based on magneto-electromechanical antenna.

[0020] Figure 2 A 20 Hz communication link demonstrated between a magneto-electromechanical antenna constructed from different magnetostrictive materials and a receiving coil.

[0021] Figure 3These are the vibration velocity response and voltage response of the magneto-electromechanical antenna under burst signal excitation.

[0022] Figure 4 The figure and experimental results of the near-field low-frequency communication system based on magneto-electromechanical antenna.

[0023] Figure 5 Schematic diagram of the in-situ synchronous vibration / voltage measurement device of the magneto-electromechanical antenna.

[0024] Figure 6 These are the vibration velocity and magnetic field response curves of the magneto-electromechanical antenna in the ranges of 47-55kHz and 20-80kHz.

[0025] Figure 7 The vibration velocity response spectrum, velocity distribution cloud map and extracted data of the magneto-electromechanical antenna under different excitation voltages. DETAILED DESCRIPTION

[0026] The following examples are used to illustrate the present invention but are not intended to limit the scope of protection of the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art. The test methods in the following examples are all conventional methods unless otherwise specified.

[0027] Example 1 Figure 1 This is a schematic diagram of a cross-medium (air-water) communication system based on a magneto-electromechanical antenna. It includes a magneto-electromechanical antenna, a receiving coil, a water container, a signal generator, a power amplifier, a static bias magnetic field applicator, and a digital oscilloscope. The magneto-electromechanical antenna is a symmetrical structure consisting of a piezoelectric layer and two magnetostrictive layers placed on either side of the piezoelectric layer. The magneto-electromechanical antenna is mounted on a bracket supporting the static bias magnetic field applicator, while the receiving coil is placed within the water container, coaxial with the magneto-electromechanical antenna's main vibration direction. This allows the magneto-electromechanical antenna's electromagnetic wave transmission signal to be generated in the air medium, while the received signal is captured in the water medium. The signal generator is connected in series with the power amplifier, which is connected to the lead wires from the magneto-electromechanical antenna's piezoelectric layer. The signal generator provides an excitation signal to the piezoelectric layer of the magneto-electromechanical antenna through the power amplifier. A digital oscilloscope is connected to the receiving coil port to acquire and display the waveform of the electromagnetic wave signal transmitted by the magneto-electromechanical antenna, captured by the receiving coil. The received signal is demodulated using Origin software on a PC.

[0028] In this embodiment, the magnetostrictive material layer in one magneto-electromechanical antenna is an iron-nickel-chromium alloy Ni-Fe-Cr (43.5% Ni, 5.8% Cr, and the rest is Fe), with a length × width × thickness = 40 mm × 6 mm × 1 mm. The iron-nickel-chromium alloy is magnetized along the length direction. The magnetostrictive material layer in the other magneto-electromechanical antenna is nickel-zinc ferrite (Ni 0.8Zn 0.2 Fe2O4, length × width × thickness = 40 mm × 6 mm × 1 mm. The nickel-zinc ferrite is magnetized along the length. The piezoelectric layers are all PZT-8, length × width × thickness = 40 mm × 6 mm × 1 mm. The PZT-8 is polarized along the thickness, with wires extending from the piezoelectric layers. The receiving coil is a solenoid with N = 200 and r = 2 cm. A lock-in amplifier (Zurich Instruments, model MFLI-500 kHz, Switzerland) was used. The NdFeB permanent magnet was a toroidal N50 NdFeB permanent magnet. A power amplifier (Aigtek, ATA-2041, China) was used. A digital oscilloscope (Tektronix, TDS2012B, China) was used. Signal generator (Tektronix AFG 3021 B). The base frequency signal of the signal generator can be flexibly selected from 10 Hz to 1 kHz (depending on the baud rate during communication operation). The signal modulation method can be selected from amplitude shift keying (ASK), frequency shift keying (FSK), or phase shift keying (PSK).

[0029] The cross-medium communication method using the cross-medium communication system based on the magneto-electromechanical antenna comprises the following steps: a. Place the magneto-electro-mechanical antenna on a bracket of a static bias magnetic field application device, and place the receiving coil in a transmission medium container, with the receiving coil coaxial with the main vibration direction of the magneto-electro-mechanical antenna; b. Turn on the signal generator and connect the modulated signal to the piezoelectric layer of the magneto-electromechanical antenna through the power amplifier; c. The receiving coil captures the electromagnetic wave signal emitted by the magneto-electromechanical antenna and transmits the voltage signal to the digital oscilloscope. The received signal is then demodulated by the PC Origin software to achieve cross-media communication.

[0030] Figure 2 A 20 Hz communication link demonstrated between a magneto-electromechanical antenna constructed from different magnetostrictive materials and a receiving coil. Figure 2 -a is a 20 Hz communication link consisting of a magneto-electromechanical antenna and a receiving coil made of iron-nickel-chromium alloy (Ni–Fe–Cr) in air; Figure 2 -b is a 20 Hz communication link between a magneto-electromechanical antenna and a receiving coil made of Ni–Fe–Cr alloy in an air-water environment. Figure 2 -c is nickel-zinc ferrite (Ni 0.8 Zn 0.2 The 20 Hz communication link between the magneto-electromechanical antenna composed of Fe2O4 and the receiving coil. The input excitation voltage for the above three experiments is 10 V. pp ,Depend on Figure 2-a, the demodulated signal voltage amplitude of the magneto-electromechanical antenna composed of FeNiCr alloy in air medium is 0.76 V, which is obtained by Figure 2 -b, the demodulated signal voltage amplitude of the magneto-electromechanical antenna composed of iron-nickel-chromium alloy in a cross-medium environment is 0.015V, which is obtained by Figure 2 -c, the demodulated signal voltage amplitude of the magneto-electromechanical antenna composed of nickel-zinc ferrite in air medium is 0.33 V. Figure 2 -a and Figure 2 -c comparison shows that the antenna radiation capability of the magneto-electromechanical antenna composed of iron-nickel-chromium alloy is significantly higher (about 2.5 times) than that of the magneto-electromechanical antenna composed of nickel-zinc ferrite. The above difference can be attributed to the high Q value and low loss characteristics of the magneto-electromechanical antenna composed of iron-nickel-chromium alloy, which has stronger radiation intensity under the same excitation and the same distance.

[0031] Figure 3 Figure 3 shows the vibration velocity response and voltage response of the magneto-electromechanical antenna under burst signal excitation. The magneto-electromechanical antenna is driven by the output voltage of a signal generator. The period and number of cycles of the pulse voltage are set to 40 ms and 300, respectively. The peak vibration velocity is obtained by a lock-in amplifier. Figure 3 -a shows that under 1 Vpp voltage excitation, the vibration speed of the magneto-electromechanical antenna rises to a maximum value (60 mm / s) at -1.5ms and decays to zero after 11ms. Figure 3 -b is a characterization of the electro-mechanical-magnetic process of the magneto-electro-mechanical antenna. The response voltage of the magneto-electro-mechanical antenna rises to a maximum value of 13 mV at -5 ms and decays to zero in 9 ms.

[0032] Figure 4 This paper provides a physical diagram and experimental results of a near-field low-frequency communication system based on a magneto-electromechanical antenna. By comparing the magnetic induction signal strength of the air-air and air-water antennas, the effects of the excitation voltage (0-170 Vpp, step 3 Vpp) and communication distance (0-1.2m) on signal transmission are analyzed. Figure 4 -a shows a physical picture of an air-to-air near-field low-frequency communication system based on a magneto-electromechanical antenna, which is driven by a power amplifier connected in series with a signal generator. Figure 4 -b shows that the magnetic flux density increases rapidly in the driving voltage range of 0~40 Vpp, and increases slowly in the range of 40~170 Vpp and tends to be flat. Figure 4 Figure 2-c shows that the magnetic field strength of the magneto-electromechanical antenna decays approximately as the 2.8th power of the distance, which is consistent with theoretical predictions (red line). Due to the sensitivity limitations of the receiving coil and the lack of appropriate magnetic shielding, the magnetic field radiation from the magneto-electromechanical antenna's EMM resonant system was measured only within a range of 1.2 m. Under 0.02 mW excitation, the magnetic field strength at 100 m is predicted to be approximately 9 pT. Figure 4 -d shows a real picture of a near-field low-frequency communication system based on a magneto-electromechanical antenna in an air-water environment. The magneto-electromechanical antenna is driven by a power amplifier connected in series with a signal generator. Figure 4 -e shows that in the air-water experimental environment, the magnetic flux density rises rapidly in the 0-40 Vpp driving voltage range, and then slowly increases in the 40-170 Vpp range and tends to be flat. Compared with the experimental data in the air-air environment, the trend is the same, but the value decreases. Figure 4 Figure -f shows that the attenuation trend of the magnetic field strength of the magneto-electromechanical antenna in the air-water experimental environment is roughly the same as that in the air-air experimental environment, decreasing approximately as the distance is raised to the power of 2.8. This is consistent with theoretical predictions (red line). Due to the sensitivity limitations of the receiving coil and the lack of appropriate magnetic shielding measures, the magnetic field radiation of the antenna's EMM resonant system was measured only within a range of 1.2 meters. Under 0.02 mW excitation, the predicted magnetic field strength at 100 meters is approximately 5.2 pT.

[0033] Example 2 Figure 5 This invention relates to an in-situ synchronous vibration / voltage measurement device for a magneto-electromechanical antenna. The device comprises a magneto-electromechanical antenna, a receiving coil, a static bias magnetic field application device, a Doppler vibrometer, a lock-in amplifier, and a personal computer. The lead wire from the piezoelectric layer of the magneto-electromechanical antenna is connected to the voltage output terminal of the lock-in amplifier, the receiving coil port is connected to the voltage input terminal I of the lock-in amplifier, and the voltage output terminal of the Doppler vibrometer's built-in velocity decoder is connected to the voltage input terminal II of the lock-in amplifier. The lock-in amplifier is connected to the PC via a communication cable. The magneto-electromechanical antenna is fixed to the middle bracket of the static bias magnetic field application device. The PC uses a program to adjust the input voltage of the lock-in amplifier to the piezoelectric layer of the magneto-electromechanical antenna and the bias magnetic field applied by the static bias magnetic field application device.

[0034] In this example, the instrument includes a lock-in amplifier (Zurich Instruments, model MFLI-500 kHz, Switzerland); a Doppler vibrometer (Polytec, Germany, model OFV-5000 / 505), which emits a 632nm helium-neon laser beam; a velocity decoder (Polytec, Germany, model VD-09); and a USB-GPIB communication cable (National Instruments, USA, model USBGPIB-HS). Labone software is installed on the PC, which primarily performs instrument control, data acquisition, human-computer interaction, and data storage. The magnetoelectric mechanical antenna is a symmetrical structure consisting of a piezoelectric layer and two magnetostrictive layers placed on either side of the piezoelectric layer. The magnetostrictive layer is a Ni–Fe–Cr alloy (43.5% Ni, 5.8% Cr, the remainder Fe), measuring 40 mm (length × width × thickness) by 6 mm (length × width × thickness) by 1 mm, magnetized along its length. The piezoelectric layer is a PZT-8 alloy, measuring 40 mm (length × width × thickness) by 6 mm (length × width × thickness) by 1 mm, polarized along its thickness. A wire leads from one side of the piezoelectric layer (the feedback side), while a reflective film is applied to the other side (the non-feedback side). The receiving coil is a solenoid with N = 200 and r = 2 cm. The solenoid diameter must be slightly larger than the width of the magnetoelectric antenna sample (with a tolerance of no more than 5%) to prevent contact between the sample and the solenoid. This ensures free vibration of the sample while maintaining the sensitivity of the captured induced electromotive force signal. The NdFeB permanent magnet is a ring-shaped N50 NdFeB permanent magnet.

[0035] The present invention provides an in-situ synchronous measurement method for the vibration / voltage in-situ synchronous measurement device of the magneto-electromechanical antenna, comprising the following steps: a. Place the magneto-electromechanical antenna on the central axis of the receiving coil and fix it to the center of the bracket; b. adjusting the input voltage of the lock-in amplifier to the piezoelectric layer of the magneto-electromechanical antenna and the magnitude of the bias magnetic field applied by the static bias magnetic field applying device through a program; e. Start the Doppler vibrometer, so that the laser beam passes through the focusing hole of the static bias magnetic field application device and focuses on the center position of the end face of the piezoelectric layer of the magneto-electromechanical antenna with a reflective film; d. The vibration velocity signal of the end face of the piezoelectric layer of the magneto-electromechanical antenna is converted into a voltage signal by the velocity decoder built into the Doppler vibrometer, transmitted to the PC via a lock-in amplifier, and then converted into vibration velocity according to the voltage-velocity conversion formula; e. The receiving coil captures the electromagnetic wave signal emitted by the magneto-electromechanical antenna and transmits the voltage signal to the lock-in amplifier.

[0036] During measurement, a bias magnetic field is applied longitudinally along the MEM antenna sample by a NdFeB permanent magnet fixed to a magnetic track. Voltage excitation is generated by an oscillating AC voltage signal source within a lock-in amplifier. The voltage excitation generates longitudinal vibrations in the MEM antenna's piezoelectric layer through electro-mechanical-magnetic coupling. The reflected light is captured by a Doppler sensor, compared with a reference beam, and converted into a voltage signal by a velocity decoder. This signal is then transmitted to a PC via the GPIB-USB interface through the lock-in amplifier, where it is reconverted into vibration velocity using a voltage-to-velocity conversion formula. Simultaneously, the magnetic field generated by the MEM antenna is captured by an external receiving coil, and the voltage signal is transmitted to the lock-in amplifier. The PC then displays both the vibration velocity and magnetic field strength. This allows the MEM antenna's vibration velocity and magnetic field voltage signals to be acquired simultaneously using the same lock-in amplifier without moving the antenna.

[0037] Figure 6 The vibration velocity and magnetic field response curves of the magneto-electromechanical antenna in the range of 47~55kHz and 20~80kHz are shown. Figure 6 -a, under the excitation voltage of 1 Vpp and the optimal bias magnetic field, the vibration / voltage in-situ measurement device of the magneto-electromechanical antenna is used to obtain f r =51.5 kHz, the magneto-electromechanical antenna vibration velocity reaches a maximum value of 86.8 mm / s. At the same time, the inverse ME coupling curve in the range of 21~81 kHz is peaked, with a sharp rise and fall of inverse MEVC near the peak. The change is relatively gentle and far below the peak at a distance from the resonant frequency. Figure 6 -b, at H=59 Oe, f r =51.5 kHz, the inverse ME coupling coefficient reaches a maximum value of 14Gs / V.

[0038] Figure 7 To obtain the vibration velocity response spectrum, simulate the velocity distribution cloud, and extract data for the magneto-electromechanical antenna under different excitation voltages using an in-situ synchronous vibration / voltage measurement device, a finite element model (FEM, COMSOL version 6.2) was used to predict the vibration velocity and stress under different excitations to study the distribution changes under EMR conditions. In the simulation, the material properties and dimensions of the magneto-electromechanical antenna were specified, and the center position of the antenna was fixed to fully restore the true strain-mediated electro-mechanical response. Assuming the magneto-electromechanical antenna is placed in a vacuum, the saturation magnetostriction coefficient is specified to be 200 ppm, the magnetic susceptibility is 200, and the saturation magnetization is 1.5×10 -6 A / m to approximate the real magnetic and magnetostrictive properties of FeNiCr, and the harmonic perturbation and gauge fixing are activated and considered in the COMSOL simulation to minimize the error, with a preset error tolerance of 0.5%. Figure 7 -a~ Figure 7 -d Inset shows the designed ME antenna in 0-5×10 -5 The velocity distribution cloud diagram in the range of m / s, with a DC magnetic field excitation of 59Oe. Subsequently, the original simulation data of the vibration velocity and stress along the long axis of the magneto-electromechanical antenna were extracted under the excitation voltage varying from 1 to 9Vpp and plotted on Figure 7 -e~ Figure 7 -f. Figure 7 -e shows the vibration velocity response curve of the magneto-electromechanical antenna along the long axis under different excitation voltages. In the resonant state, the vibration is slowest at the middle position of the magneto-electromechanical antenna due to being fixed, and the vibration velocity increases as it approaches the two ends. Under 1, 3, 6, and 9 Vpp excitation, the vibration velocity at the middle position (0 mm) is 10.1, 16.6, 17.8, and 18.5 μm / s, respectively, and the vibration velocity at the end (non-feed side) (20 mm) is 30.26, 48.6, 52.5, and 54.4 μm / s. Figure 7 -f shows the stress response curve of the magneto-electromechanical antenna along the long axis under different excitation voltages. Under 1, 3, 6, and 9 Vpp excitations, the stress at the center of the magneto-electromechanical antenna is 238, 351.6, 375.8, and 387.7 N / m, respectively. 2 , which is proportional to the excitation voltage of the magneto-electromechanical antenna.

[0039] In summary, the measured vibration velocity data is slightly lower than the simulated data (≈98%), demonstrating the reliability of the measured data. This discrepancy is due, in part, to the presence of a micron-scale air gap in the epoxy resin between the piezoelectric and magnetostrictive layers (perfect bonding was assumed in the simulation), which reduces strain transfer efficiency. Furthermore, micron-scale elastic deformation of the beryllium copper used to secure the antenna in the experiment reduces effective stiffness, resulting in the measured velocity being slightly lower than the simulated velocity.

[0040] The embodiments described above are only preferred embodiments of the present invention and are only used to explain the present invention, not to limit the scope of implementation of the present invention. For those skilled in the art, it is of course possible to easily make other implementation methods by replacing or changing the technical content disclosed in this specification. Therefore, all changes and improvements made on the principles of the present invention should be included in the scope of the patent application of the present invention.

Claims

1. A cross-medium communication system based on a magneto-electromechanical antenna, characterized in that: The device comprises a magneto-electro-mechanical antenna, a receiving coil, a transmission medium container, a signal generator, a power amplifier, and a static bias magnetic field application device. The magneto-electro-mechanical antenna is a symmetrical structure consisting of a piezoelectric layer and two magnetostrictive layers placed on either side of the piezoelectric layer. The magneto-electro-mechanical antenna is placed on a bracket of the static bias magnetic field application device. The receiving coil is placed in the transmission medium container, and the receiving coil is coaxial with the main vibration direction of the magneto-electro-mechanical antenna. The signal generator is connected in series with a power amplifier, the power amplifier is connected to a lead wire of the piezoelectric layer of the magneto-electro-mechanical antenna, and the signal generator provides an excitation signal to the piezoelectric layer of the magneto-electro-mechanical antenna through the power amplifier; The digital oscilloscope is connected to the receiving coil port and is used to collect the electromagnetic wave signal emitted by the magneto-electromechanical antenna captured by the receiving coil.

2. The cross-medium communication system based on a magneto-electromechanical antenna according to claim 1, characterized in that: The magnetostrictive layer is made of an iron-nickel-chromium alloy, and the piezoelectric layer is made of PZT-8.

3. The cross-medium communication system based on a magneto-electromechanical antenna according to claim 1, characterized in that: The static bias magnetic field applying device is composed of NdFeB permanent magnets arranged relatively on the guide rail, and provides a static bias magnetic field for the magneto-electromechanical antenna.

4. The cross-medium communication system based on a magneto-electromechanical antenna according to claim 1, characterized in that: The transmission medium in the transmission medium holding container is water, soil or sand.

5. The cross-medium communication method of a cross-medium communication system based on a magneto-electromechanical antenna according to any one of claims 1 to 4, characterized in that: The following steps are involved: a. Place the magneto-electro-mechanical antenna on a bracket of a static bias magnetic field application device, and place the receiving coil in a transmission medium container, with the receiving coil coaxial with the main vibration direction of the magneto-electro-mechanical antenna; b. Turn on the signal generator and connect the modulated signal to the piezoelectric layer of the magneto-electromechanical antenna through the power amplifier; c. The receiving coil captures the electromagnetic wave signal emitted by the magneto-electromechanical antenna and transmits the voltage signal to a digital oscilloscope. The received signal is demodulated by the PC Origin software to achieve cross-media communication.

6. The in-situ synchronous measurement system for vibration / voltage signals of a magneto-electro-mechanical antenna in a cross-medium communication system based on a magneto-electro-mechanical antenna according to any one of claims 1 to 4, characterized in that: It includes magneto-electromechanical antenna, receiving coil, static bias magnetic field application device, Doppler vibrometer, lock-in amplifier and PC; The lead wire from the piezoelectric layer of the magneto-electro-mechanical antenna is connected to the voltage output terminal of the lock-in amplifier, the receiving coil port is connected to the voltage input terminal I of the lock-in amplifier, the voltage output terminal of the built-in velocity decoder of the Doppler vibrometer is connected to the voltage input terminal II of the lock-in amplifier, and the lock-in amplifier is connected to a PC via a communication cable; the magneto-electro-mechanical antenna is fixed to the middle bracket of the static bias magnetic field application device; The PC adjusts the input voltage of the lock-in amplifier to the piezoelectric layer of the magneto-electromechanical antenna and the magnitude of the bias magnetic field applied by the static bias magnetic field applying device through a program.

7. The vibration / voltage signal in-situ synchronous measurement method based on the vibration / voltage signal in-situ synchronous measurement system according to claim 6, characterized in that: The following steps are involved: a. Place the magneto-electromechanical antenna on the central axis of the receiving coil and fix it to the center of the bracket; b. adjusting the input voltage of the lock-in amplifier to the piezoelectric layer of the magneto-electromechanical antenna and the magnitude of the bias magnetic field applied by the static bias magnetic field applying device through a program; e. Start the Doppler vibrometer, so that the laser beam passes through the focusing hole of the static bias magnetic field application device and focuses on the center position of the end face of the piezoelectric layer of the magneto-electromechanical antenna with a reflective film; d. The vibration velocity signal of the end face of the piezoelectric layer of the magneto-electromechanical antenna is converted into a voltage signal by the velocity decoder built into the Doppler vibrometer, transmitted to the PC via a lock-in amplifier, and then converted into vibration velocity according to the voltage-velocity conversion formula; e. The receiving coil captures the electromagnetic wave signal emitted by the magneto-electromechanical antenna and transmits the voltage signal to the lock-in amplifier.

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