A distributed low-frequency magneto-electromechanical antenna transceiver system and design method

Abstract

The present invention belongs to the technical field of long-wave communication antenna systems and discloses a distributed low-frequency magneto-electro-mechanical antenna transceiver system, comprising a signal amplifier, a power amplifier, a 1:N type magneto-electro-mechanical power divider, and N communication channels arranged as distributed nodes. The 1:N type magneto-electro-mechanical power divider is composed of a magneto-electro-composite material and a coil tightly wound around the outside of the magneto-electro-composite material, with two wire ends of the coil leading out as power input ports. The magneto-electro-composite material is a symmetrical structure consisting of a piezoelectric layer and two magnetostrictive layers bonded on both sides of the piezoelectric layer. The piezoelectric layer is cut into N parts along the length direction and leads out N independent power output ports. The N communication channels are composed of N magneto-electro-mechanical antennas and N coils placed accordingly. The power output port of each 1:N type magneto-electro-mechanical power divider is connected to a lead wire of the piezoelectric layer in each magneto-electro-mechanical antenna to provide a radiation excitation source.

Description

Technical Field

[0001] The present invention belongs to the technical field of long-wave communication antenna systems, and relates to a distributed low-frequency magneto-electromechanical antenna transceiver system and a design method. Background Art

[0002] Low-frequency / very low-frequency (LF / VLF) communications use longer wavelengths, easily penetrating metal, soil, rock, and saltwater (10-20 meters). These signals offer significant advantages, including long transmission distance, strong penetration, and robust resistance to electromagnetic pulse interference. They are widely used in submarine communications, long-distance communications, long-distance navigation, wireless heart rate detectors, geophysical research, and disaster relief. However, the size of long-wave radio antennas transmitting LF / VLF signals is constrained by their wavelength. Theoretically, the antenna's transmission and reception efficiency is highest when its length is 1 / 4 the wavelength of the radio signal. This results in the need for massive, multi-mile antenna arrays for land-based VLF communication base stations. Consequently, various countries are working to improve and address the current challenges facing long-wave antennas in miniaturization, portability, and low power. In 2017, the Defense Advanced Research Projects Agency-Microsystems Office (DARPA-MTO) of the U.S. Department of Defense first released the AMEBA (AMEchanically Based Antenna) project mission, led by Dr. Troy Olsson. The program focused on finding a revolutionary solution for mechanically driven antenna transmitters to generate radio frequency signals at carrier frequencies below 30kHz. This program sought to overturn the coupling mechanism of traditional antennas, which rely on oscillating circuits to generate transmitted electromagnetic waves, and explore new methods for generating oscillating electromagnetic waves through mechanical vibration. To date, mechanical antennas can be primarily divided into two categories, based on the principles of mechanical vibration generation, electromagnetic wave radiation, and implementation methods: "mechanical motion" low-frequency mechanical antennas, represented by electret mechanical antennas and permanent magnet mechanical antennas, and "acoustically driven" low-frequency mechanical antennas, represented by piezoelectric mechanical antennas and magnetoelectric mechanical antennas.

[0003] It is worth noting that, as a type of "acoustically driven" mechanical antenna, magneto-electromechanical antennas rely on strong magneto-electric coupling between the piezomagnetic and piezoelectric phases, compared to electret / permanent magnet rotating mechanical antennas and piezo-electromechanical antennas. This combines the efficiency and precision of piezoelectric material "electric drive" with the controllable nature of magnetic dipole modulation, and is considered a key technology for the development of very low frequency communication technology. However, the 360° directivity of a single magneto-electromechanical antenna exhibits an "8"-shaped normalized directional radiation characteristic. While its significant anisotropy provides good directivity, it generates virtually no outward electromagnetic radiation at angles of 90° and 270°. Consequently, a single magneto-electromechanical antenna has a blind spot in radiation intensity, with the strongest radiation occurring only along its length, preventing it from achieving blind spot-free, full-area coverage. Summary of the Invention

[0004] In response to the technical problem that existing magnetoelectric antennas cannot achieve zero-dead-angle and full-area coverage, the present invention provides a distributed low-frequency magnetoelectric mechanical antenna transceiver system. By adjusting the position, distance and dimension of the magnetoelectric mechanical antenna, arbitrary spatial distribution of the communication system can be achieved.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a distributed low-frequency magneto-electro-mechanical antenna transceiver system, comprising a signal amplifier, a power amplifier, a 1:N type magneto-electro-mechanical power divider, and N communication channels arranged as distributed nodes;

[0007] The 1:N type magnetoelectric power divider is composed of a magnetoelectric composite material and a coil tightly wound around the outside of the magnetoelectric composite material, with two wire ends of the coil leading out as power input ports. The magnetoelectric composite material is a symmetrical structure consisting of a piezoelectric layer and two magnetostrictive layers bonded on both sides of the piezoelectric layer. The piezoelectric layer is cut into N parts along the length direction and leads out N power output ports.

[0008] The N communication channels are composed of N magneto-electromechanical antennas and correspondingly placed N coils. Each magneto-electromechanical antenna is a symmetrical structure consisting of a piezoelectric layer and two magnetostrictive layers placed on both sides of the piezoelectric layer. The power output port of each 1:N type magneto-electric power divider is connected to the piezoelectric layer lead in each mechanical transmitting unit to provide a radiation excitation source.

[0009] In the above technical solution of the present invention, the planar normalized directional pattern characteristics of each magneto-electromechanical antenna along the length and width directions and the length and thickness directions conform to the "8"-shaped radiation gain response.

[0010] In the above-mentioned technical solution of the present invention, the material and polarization mode of the magnetostrictive layer in the 1:N type magnetoelectric power distributor and each magnetoelectric mechanical antenna are consistent, and the material and polarization mode of the piezoelectric layer in the 1:N type magnetoelectric power distributor and each magnetoelectric mechanical antenna are consistent.

[0011] In the above-mentioned technical solution of the present invention, the magnetostrictive layer in the 1:N type magnetoelectric power divider and each magnetoelectric mechanical antenna is magnetized along the length direction, and the piezoelectric layer in the 1:N type magnetoelectric power divider and each magnetoelectric mechanical antenna is polarized along the thickness direction, and the magnetostrictive layer and the piezoelectric layer form an LT mode.

[0012] In the above technical solution of the present invention, the magnetostrictive layer and the piezoelectric layer in the 1:N type magnetoelectric power divider and each magnetoelectric mechanical antenna have the same width and thickness but different lengths.

[0013] In the above technical solution of the present invention, the magnetostrictive layer is nickel-zinc ferrite Ni 0.8 Zn 0.2 Fe2O4.

[0014] In the above technical solution of the present invention, the piezoelectric layer is PZT-8.

[0015] In a second aspect, the present invention provides a method for designing the above-mentioned distributed low-frequency magneto-electromechanical antenna transceiver system, comprising the following steps:

[0016] 1) Preparation 1: N-type magnetoelectric power divider: Determine the number of piezoelectric layers to be cut based on the number of communication channels required by the distributed nodes and the different drive power requirements. Measure the operating frequency range of each power output port of the magnetoelectric power divider using the magnetoelectric voltage coefficient response curve to determine the type and size of the N magnetoelectric mechanical antennas.

[0017] 2) Configuring N magneto-electro-mechanical antennas: adjusting the size of each magneto-electro-mechanical antenna and varying the magnitude of the applied DC bias magnetic field so that each magneto-electro-mechanical antenna has a consistent resonant frequency and impedance phase under a suitable DC bias magnetic field;

[0018] 3) Impedance matching between a 1:N magnetoelectric power divider and N magnetoelectric mechanical antennas: Measure the impedance phase of each power output port of the 1:N magnetoelectric power divider and each magnetoelectric mechanical antenna using an impedance analyzer. Based on the impedance phase consistency principle, connect the piezoelectric layer leads of each magnetoelectric mechanical antenna to the corresponding power output ports of the 1:N magnetoelectric power divider to maximize the driving power of each power output port of the 1:N magnetoelectric power divider.

[0019] 4) Configuring N communication channels: Using the center line of the magnetization direction of the magnetostrictive layer as the strongest radiation path, align each magneto-electromechanical antenna with the center line of the corresponding coil along the strongest radiation path to obtain a communication channel with the strongest radiation gain;

[0020] 5) Configure a distributed low-frequency magneto-electro-mechanical antenna transceiver system: Adjust the position, dimension, and angle of each communication channel to obtain a distributed magneto-electro-mechanical antenna transceiver system with different signal inputs and multi-channel outputs.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention uses a magnetoelectric power divider, a magnetoelectric mechanical antenna, and a coil to construct a low-frequency communication system. Each port of the 1:N type power divider corresponds to and provides an independent excitation source, forming N effective radiation units. Each effective radiation unit forms the strongest radiation path along the magnetization direction of each mechanical antenna's magnetostrictive layer. The signal is input to the magnetoelectric power divider and the input power is distributed to multiple communication channels according to the required proportion. By placing the magnetoelectric mechanical antennas at different positions, distances, and dimensions, arbitrary spatial distribution of the communication system can be achieved to meet different needs in practical applications, such as individual underwater communication and special application scenarios of distributed communication nodes such as underground communication mines, tunnels, and collapsed buildings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The figure is a schematic diagram of the communication principle and structure of the distributed low-frequency magneto-electromechanical antenna transceiver system of the present invention.

[0024] Figure 2 Schematic diagram of the communication principle and structure of the distributed low-frequency magneto-electromechanical antenna transceiver system in Example 1.

[0025] Figure 3 1 is the impedance phase diagram of the two power output ports of the 1:2 type magnetoelectric power divider in Example 1.

[0026] Figure 4 This is a set of graphs showing positive magnetoelectric voltage coefficient curves of the two power output ports of the 1:2 magnetoelectric power divider in Example 1 under different DC biases.

[0027] Figure 5 1 is a set of graphs showing the impedance phase, inverse magnetoelectric voltage coefficient under different DC biases, and 3 dB bandwidth of the magnetoelectric mechanical antennas MA1 and MA2 in Example 1 as a function of DC bias.

[0028] Figure 6 This is a set of graphs showing the conversion efficiency, output voltage and port voltage ratio of the two power output ports of the 1:2 type magnetoelectric power divider in Example 1 at 57500 Hz as a function of load resistance.

[0029] Figure 7 : are the radiation patterns of the magneto-electromechanical antenna MA1 in Example 1 at 57500 Hz on three coordinate planes.

[0030] Figure 8 : are the radiation patterns of the magneto-electromechanical antenna MA2 in Example 1 in three coordinate planes at 57500 Hz.

[0031] Figure 9 This is a graph showing the loss test of the induced magnetic field generated by the magneto-electromechanical antennas MA1 and MA2 at 57500 Hz as the distance varies in Example 1.

[0032] Figure 10 1 is a radiation response diagram of the induced magnetic field and input power generated by the magneto-electromechanical antennas MA1 and MA2 at 57500 Hz as the driving voltage changes.

[0033] Figure 11 This is a timing diagram of modulation and demodulation of amplitude shift keying in channel 1 and channel 2 of the communication system in Example 1. DETAILED DESCRIPTION

[0034] 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.

[0035] Figure 1 The communication schematic and substructure diagram of the distributed low-frequency magneto-electro-mechanical antenna transceiver system of the present invention are shown. The distributed low-frequency magneto-electro-mechanical antenna transceiver system includes a signal amplifier, a power amplifier, a 1:N magneto-electric power divider, and N communication channels arranged as distributed nodes.

[0036] In the present invention, 1:N type magnetoelectric power distributor is composed of a magnetoelectric composite material and a coil tightly wound outside the magnetoelectric composite material, the two wire ends of the coil are led out as power input ports, the magnetoelectric composite material is a symmetrical structure consisting of a piezoelectric layer and two magnetostrictive layers bonded on the upper and lower sides of the piezoelectric layer, the piezoelectric layer is cut into N parts along the length direction and leads out N independent power output ports.

[0037] In the present invention, N communication channels are composed of N magneto-electro-mechanical antennas and correspondingly placed N coils. Each magneto-electro-mechanical antenna is a symmetrical structure consisting of a piezoelectric layer and two magnetostrictive layers placed on both sides of the piezoelectric layer. The power output port of each 1:N type magneto-electro-electric power divider is connected to the piezoelectric layer lead in each magneto-electro-mechanical transmitting unit to provide a radiation excitation source.

[0038] The magnetostrictive layer in the magnetoelectric power distributor and magnetoelectric mechanical antenna of the present invention is magnetized along the length direction (L), and the piezoelectric layer is polarized along the thickness direction (T), forming an LT mode. The two wire ends of the coil in the magnetoelectric power distributor serve as power input ports, and N independent power output ports (Port1, Port2, ..., Portn) are drawn from the silver electrode surfaces on the upper and lower sides of each piezoelectric layer of the magnetoelectric power distributor. The N power output ports are respectively connected to N magnetoelectric mechanical antennas (MA1, MA2, ..., MAn). The magnetoelectric power distributor converts the input power and distributes it to each output port for output. The magnetoelectric mechanical antenna generates an alternating magnetic field through the inverse magnetoelectric effect and radiates it. The output is captured by the receiving coil. Each magnetoelectric mechanical antenna and coil constitute an independent communication channel of the system.

[0039] In the distributed low-frequency magneto-electro-mechanical antenna transceiver system of the present invention, the magneto-electro-mechanical antenna serves as the transmitting unit, and the coil serves as the receiving unit. The two always appear in pairs. By combining them one by one, the distributed long-wave communication needs deployed in different locations, dimensions, and angles are met, forming a low-frequency / very low-frequency communication channel. Each power output port of the magneto-electro-mechanical power divider corresponds to each magneto-electro-mechanical antenna and provides an independent excitation source, forming N effective radiation units. Each effective radiation unit forms the strongest radiation path along the magnetization direction of the magnetostrictive layer of each mechanical antenna. Therefore, each magneto-electro-mechanical antenna is aligned with the center line of the corresponding coil along the strongest radiation path to obtain a communication channel with the strongest radiation gain. At the same excitation frequency, the resonant operating frequency generated by the N power output ports remains consistent, and this frequency determines the type, size, and actual operating frequency of the magneto-electro-mechanical antenna.

[0040] The length ratio of each piezoelectric layer in the magnetoelectric power divider of the present invention determines the effective electrode area ratio, and thus determines the power division ratio of the magnetoelectric power divider. Therefore, the piezoelectric layer can be cut into equal or unequal parts along the length direction. The impedance ratio of the N power output ports is approximately equal to the effective electrode area ratio of the piezoelectric layer at each port, and has good impedance matching with each magnetoelectric mechanical antenna, so that the driving power of the mechanical antenna transmitting unit is maximized. For example, if the effective electrode area ratio of the piezoelectric layer is 3 times of 1:2:3, then the power ratio of the corresponding three communication channels is 1:2:3.

[0041] The frequency response of the N magneto-electromechanical antennas in the present invention belongs to the category of directional antennas. The radiation gain generated in all directions under normalization is consistent, and the characteristics of the plane-normalized radiation patterns along the length and width directions and the length and thickness directions conform to the "8"-shaped radiation gain response, generating the strongest radiation gain along the length direction, and the characteristics of the plane-normalized radiation patterns along the width and thickness directions are close to isotropic radiation gain.

[0042] The present invention can deploy each communication channel at different positions, dimensions and angles to obtain different distributed magneto-electromechanical antenna transceiver systems with signal input and multi-channel output, thereby realizing arbitrary spatial distribution of the communication system and meeting different needs in practical applications.

[0043] Example 1

[0044] Figure 2 The following is a schematic diagram of the communication principle and structure of the distributed low-frequency magneto-electro-mechanical antenna transceiver system of this embodiment. The communication system includes a signal generator (model: Agilent 33250A), a power amplifier (model: Aigtek ATA-2041 High Voltage Amplifier), a 1:2 magneto-electro-mechanical power divider, two magneto-electro-mechanical antennas, and two coils.

[0045] Production of 1:2 type magnetoelectric power divider: The material used for the magnetostrictive layer is nickel-zinc ferrite Ni 0.8 Zn 0.2 Fe2O4 is magnetized along the length direction (L), solid-state sintered into blocks and then cut into sheets, length × width × height = 37mm × 6mm × 1mm. The piezoelectric layer is PZT-8, length × width × height = 40mm × 6mm × 1mm, polarized along the thickness direction (T), and the piezoelectric layer is cut into two pieces along the length direction with an effective electrode area ratio of 1:1. The upper and lower silver electrode surfaces of each piezoelectric layer serve as the power output port I (Port 1) and power output port II (Port 2) of the magnetoelectric power divider respectively. The magnetostrictive layer is bonded to both sides of the piezoelectric layer with epoxy resin, and after it is fully solidified, a copper coil with a diameter of 40mm and a total of 200 turns is tightly wound. The two ends of the coil are led out as power input ports to obtain a 1:2 magnetoelectric power divider. Its structure and principle are shown as follows. Figure 2 (c) shown.

[0046] Making communication channel: The material used for magnetostrictive layer is Ni 0.8 Zn 0.2 The Fe2O4 material is 37mm long, 6mm wide, and 1mm wide, and is magnetized along the length direction (L). The piezoelectric material layer is PZT-8, 40mm long, 6mm wide, and 1mm wide, and is polarized along the thickness direction (T). Magnetostrictive layers are bonded to the upper and lower sides of the piezoelectric layer using epoxy resin, forming the magneto-electromechanical antennas MA1 and MA2. The corresponding receiving coils for the magneto-electromechanical antennas have a radius of 1.96cm, a length of 5.8cm, and an internal resistance of 9Ω.

[0047] Figure 2(a) shows the communication principle of the system. From signal input to the output of the two communication channels, the positive and negative magnetoelectric effects are experienced successively. The input electrical signal is modulated by the signal generator, amplified by the power amplifier, and then output from the closely spaced coil lead port V of the 1:2 power divider (PS). in The positive magnetoelectric effect generates an alternating magnetic field. Output ports Port1 and Port2 are connected to the upper and lower sides of each piezoelectric layer. The power divider converts the input power and divides it equally between Port1 and Port2, which are connected to the magnetomechanical antennas MA1 and MA2 respectively. MA1 and MA2 generate an alternating magnetic field through the inverse magnetoelectric effect and radiate it. The receiving coil captures the output V out1 and V out2 , each magneto-electromechanical antenna is coaxially placed with the receiving coil so that the communication channel operates in the strongest radiation path, forming the communication channel 1 and channel 2 of the system.

[0048] exist Figure 2 In the schematic diagram (b), the input signal is evenly split across the effective electrode area at a 1:1 ratio, outputting ports 1 and 2. MA1 and MA2, along with their corresponding coils, are coaxially aligned along the centerline, forming two communication channels. Ports 1 and 2 are independently powered by a 1:2 power divider. By varying the angle, distance, and dimensions of the communication channels formed by MA1 and MA2 and their corresponding coils, arbitrary spatial distribution of the communication system is possible.

[0049] Figure 3 The impedance phase diagram of the two power output ports of the 1:2 type magnetoelectric power divider in this embodiment is shown in Figure 2. The measurement device includes an impedance analyzer (model: KEYSIGHT E4990A) and a desktop computer equipped with its corresponding software system. The measured impedance phase curves of Port 1 and Port 2 have the same trend and similar values. Figure 3 (a) and Figure 3 (b) When the measured frequency is 57500 Hz, the impedance of Port 1 is 11381 Ω and the phase is -21.8 degrees; the impedance of Port 2 is 8836 Ω and the phase is -11.3 degrees.

[0050] Figure 4The following is a set of graphs showing the positive magnetoelectric voltage coefficient curves of the two power output ports of the 1:2 type magnetoelectric power divider in this embodiment under different DC bias conditions. The test device for the positive magnetoelectric voltage coefficient curves of each port includes: a phase-locked amplifier (model: Zurich MFLI-500kHz), a desktop computer equipped with the corresponding Labone software system, and an adjustable DC bias magnetic guide rail. During the test, the coil of the magnetoelectric power divider is used as the input port, and each power output port is tested separately as the output port. By setting the excitation voltage to 282.8mV, setting the sweep frequency range to (55-62kHz), and changing the DC bias value, a set of graphs showing the amplitude-frequency characteristics of the output voltage of the two output ports changing with frequency under different DC bias conditions can be measured.

[0051] Figure 5 : is a set of graphs showing the impedance phase, inverse magnetoelectric voltage coefficient under different DC bias and 3dB bandwidth of the magnetoelectric mechanical antennas MA1 and MA2 in this embodiment as the DC bias changes. Figure 5 (a) and Figure 5 (e) is the impedance phase curve of the magneto-electromechanical antennas MA1 and MA2. The test device and principle are similar to Figure 2 The tests on each port of the magnetoelectric power divider are consistent. Figure 5 (b) and Figure 5 (f) is the reverse magnetoelectric voltage coefficient curve of MA1 and MA2 under different DC bias, which is measured by placing them inside a coil (radius 1.96cm, length 5.8cm, internal resistance 9Ω). The test device and principle are the same as Figure 3 The tests on each port of the magnetoelectric power divider are consistent, where the coil is used as the input port, the sweep frequency range is set to (56.5~61.5kHz), and the rest remain unchanged. Figure 5 (c) and Figure 5 (d) is a bandwidth group diagram obtained according to the 3dB range of the resonant frequency under different DC biases. It is observed that the resonant frequency of MA2 under different biases is around 57503Hz, and the 3dB bandwidth range moves slightly to the right. At 31Oe, it has the relatively highest reverse magnetoelectric voltage coefficient, so 31Oe is selected as the DC bias of MA2; when the bias of MA1 increases from 16 to 31Oe, the resonant frequency is around 57459Hz, and the 3dB bandwidth range also has a tendency to move slightly to the right. The change is more obvious at 41Oe, and the resonant frequency is 57496Hz, which is also closest to the working bandwidth of MA2 at 31Oe, so 41Oe is selected as the DC bias of MA1. Since the resonant frequencies of MA2 at 31Oe and MA1 at 41Oe are 57503Hz and 57496Hz respectively, 57500Hz is selected as the working frequency point for the communication system test. Figure 5 (c) and Figure 5As shown in the inset of (d), for the operating frequency point of 57500Hz, the maximum inverse magnetoelectric voltage coefficient of MA1 under different DC bias is 9.21 measured at 41Oe; the maximum inverse magnetoelectric voltage coefficient of MA2 under different DC bias is 7.24 measured at 31Oe. Figure 5 (a) and Figure 5 (e) At the measured frequency of 57500 Hz, the impedance of MA1 is 10867 Ω and the phase is 31.7 degrees; the impedance of MA2 is 9440 Ω and the phase is 69.8 degrees. Using the impedance approximation matching method, Port 1 is connected to MA1, and Port 2 is connected to MA2. Considering the loss of impedance transformation, a direct connection method is used for system construction when the impedance difference between the magnetoelectric power divider port and the mechanical antenna is small.

[0052] Figure 6 The following graphs show the conversion efficiency, output voltage, and port voltage ratio of the two power output ports of the 1:2 magnetoelectric power divider in this embodiment at 57,500 Hz as a function of load resistance. The test setup included a signal generator (Model: Agilent 33250A), a 200Ω resistor, a sliding rheostat (Model: Shanghai Dongmao Technology ZX21F), an oscilloscope (Model: Tektronix TDS2012B), a data acquisition board (Model: NI Instruments PCI-6250), a BNC connector (NI Instruments BNC-2110), an adjustable DC bias magnetic guide rail, and a desktop computer with the corresponding Labview software system. During the test, the signal generator served as the input source, set to a sine wave with an amplitude of 200 mV and a frequency of 57,500 Hz (operating point). Its output port was connected in series with a 200Ω resistor and then to the power divider coil. Connect the resistor in series to the input circuit to detect the input current (I0), connect the coil in parallel to the input circuit to detect the input voltage (U0), and connect them to the two ports of the oscilloscope respectively. By multiplying them, the total input power of the magnetoelectric power divider ( By connecting the output port of the magnetoelectric power divider to the resistor box (R1), the acquisition board, BNC connector and desktop computer are used to collect the voltage on the variable resistor as the output voltage (U1), and the output power (P out =((U1)^2) / R1). Divide the output power by the input power to get the conversion efficiency of each output port. The test results are as follows Figure 6 (a) and Figure 6As shown in (b), at a frequency of 57500Hz, when the port Port1 of the magnetoelectric power divider is connected to the load MA1, the conversion efficiency is close to 25%; when the port Port2 is connected to the load MA2, the conversion efficiency is also close to 25%. That is, the conversion efficiency of the magnetoelectric power divider is about 50% at this time. Define the output voltages of Port1 and Port2 when the conversion efficiency is tested at different load resistances as Vout1 and Vout2, and the voltage ratio (S = Vout1 / Vout2), and obtain the graph of the output port voltage ratio of the magnetoelectric power divider changing with the load resistance ( Figure 6 (c)), the ratio is close to 1, that is, each output port of the magnetoelectric power divider has a good tearing ratio.

[0053] Figure 7 The radiation patterns of the magneto-electromechanical antenna MA1 in this embodiment at 57500 Hz in three coordinate planes are shown. The test setup includes a coil (radius 1.96 cm, length 5.8 cm, internal resistance 9 Ω) as a receiving antenna, a lock-in amplifier (model: Zurich MFLI-500kHz), and a desktop computer with the corresponding Labone software system. The excitation voltage was set to 282.8 mV and the DC bias was set to 41 Oe. The response values ​​of the magneto-electromechanical antenna in each plane were measured, and the data were normalized using Origin-2023 software. Figure 7 (a) is a schematic diagram of the three-dimensional coordinate system for each plane test. Figure 7 (b) is the yz plane direction diagram, Figure 7 (c) is the xz plane pattern, Figure 7 (d) is the xy plane directional diagram.

[0054] Figure 8 The radiation patterns of the magnetoelectric mechanical antenna MA2 in this embodiment at 57500 Hz in three coordinate planes are shown. The test setup includes a coil (radius 1.96 cm, length 5.8 cm, internal resistance 9 Ω) as a receiving antenna, a lock-in amplifier (model: Zurich MFLI-500kHz), and a desktop computer equipped with the corresponding Labone software system. The excitation voltage was set to 282.8 mV and the DC bias was set to 31 Oe. The response values ​​of the magnetoelectric antenna in each plane were measured, and the data were normalized using Origin-2023 software. Figure 8 (a) is a schematic diagram of the three-dimensional coordinate system for each plane test. Figure 8 (b) is the yz plane direction diagram, Figure 8 (c) is the xz plane pattern, Figure 8 (d) is the xy plane directional diagram.

[0055] Figure 9The following diagram shows the loss of the induced magnetic field generated by the magneto-electromechanical antennas MA1 and MA2 at 57,500 Hz, as measured by distance. The test setup included a coil (radius 1.96 cm, length 5.8 cm, internal resistance 9 Ω) as a receiving antenna, a lock-in amplifier (model: Zurich MFLI-500kHz), a desktop computer equipped with the corresponding Labone software system, a power amplifier (model: Aigtek ATA-2041 High Voltage Amplifier), and an oscilloscope (model: Tektronix TDS2012B). During the test, the output port of the lock-in amplifier was connected to the input port of the power amplifier, and a sinusoidal wave with a peak output voltage of 2 V and a frequency of 57,500 Hz (operating point) was set. The voltage and current monitoring ports of the power amplifier were connected to the two ports of the oscilloscope, respectively, and the input power was obtained by multiplying them. By varying the power amplifier's gain, the input power was limited to 200 mW. During the test, the DC bias of MA1 was set to 41Oe, and the DC bias of MA2 was set to 31Oe. The output port of the power amplifier was connected to the mechanical antenna under test, and the receiving coil was connected to the input port of the phase-locked amplifier. By changing the distance between the antenna and the receiving coil, the phase-locked amplifier captured the voltage response at the corresponding distance and converted the voltage value into an induced magnetic field. Under the condition of fixed input power, the induced magnetic field of MA1 and MA2 changed with distance as shown below. Figure 9 (a) and Figure 9 (b) shown.

[0056] Figure 10The following is a graph showing the radiation response of the induced magnetic field and input power generated by the magneto-electro-mechanical antennas MA1 and MA2 at 57,500 Hz as the driving voltage changes. The test apparatus includes a coil (radius 1.96 cm, length 5.8 cm, internal resistance 9 Ω), a lock-in amplifier (model: Zurich MFLI-500kHz), a desktop computer equipped with the corresponding Labone software system, a power amplifier (model: Aigtek ATA-2041 High Voltage Amplifier), and an oscilloscope (model: Tektronix TDS2012B). During the test, the DC bias of MA1 was set to 41 Oe, and the DC bias of MA2 was set to 31 Oe. The distance between the coil and the mechanical antenna was fixed at 10 cm. The lock-in amplifier was set to output a sine wave with a peak voltage of 3 V and a frequency of 57,500 Hz (operating point). The power amplifier was set to provide the magneto-electro-mechanical antenna with a voltage range of 0 to 120 V in 3 V increments. The current and voltage monitoring ports of the power amplifier are connected to an oscilloscope and multiplied to detect the output power of the power amplifier at each voltage point. The phase-locked amplifier detects the output response of the magnetoelectric antenna at each voltage point. Under the condition of a fixed distance, the induced magnetic field and driving power of MA1 and MA2 are detected as the driving voltage changes, respectively. Figure 10 (a) and Figure 10 (b) shown.

[0057] Figure 11 The following is a timing diagram of the modulation and demodulation of the amplitude shift keying in channel 1 and channel 2 of the communication system of this embodiment. The test device includes a signal generator (model: Agilent 33250A) and an oscilloscope (model: Tektronix TDS2012B). During the test, the DC bias of the power divider is set to 36Oe, the DC bias of MA1 is set to 41Oe, and the DC bias of MA2 is set to 31Oe. The distance between the receiving coil and the mechanical antenna is fixed at 10cm, and the center line of the mechanical antenna is aligned with the center line of the receiving coil. By setting the signal generator to output a fundamental wave of 10Hz square wave, a carrier wave of 57500Hz frequency, an amplitude of 10V, and an amplitude shift keying modulation wave of 100% depth, the coil lead input of the power divider is connected. MA1 and MA2 are connected to Port1 and Port2 of the power divider respectively. The transmission signals of MA1 and MA2 are captured by the receiving coil and displayed on the oscilloscope as shown below. Figure 11 (a) and Figure 11 As shown in (b), from top to bottom are the fundamental waveforms of channel 1 and channel 2, the modulation waveforms, and the received waveforms transmitted by MA1 and MA2.

[0058] 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 distributed low-frequency magneto-electromechanical antenna transceiver system, characterized in that: It includes a signal amplifier, a power amplifier, a 1:N type magnetoelectric power divider and N communication channels arranged as distributed nodes; The 1:N type magnetoelectric power divider is composed of a magnetoelectric composite material and a coil tightly wound around the outside of the magnetoelectric composite material, with two wire ends of the coil leading out as power input ports. The magnetoelectric composite material is a symmetrical structure consisting of a piezoelectric layer and two magnetostrictive layers bonded on both sides of the piezoelectric layer. The piezoelectric layer is cut into N parts along the length direction and leads out N power output ports. The N communication channels are composed of N magneto-electro-mechanical antennas and correspondingly placed N coils. Each magneto-electro-mechanical antenna is a symmetrical structure consisting of a piezoelectric layer and two magnetostrictive layers placed on both sides of the piezoelectric layer. The power output port of each 1:N type magneto-electro-mechanical power divider is connected to the piezoelectric layer lead in each magneto-electro-mechanical antenna to provide a radiation excitation source.

2. A distributed low-frequency magneto-electromechanical antenna transceiver system according to claim 1, characterized in that: The plane-normalized directional pattern characteristics of each magneto-electromechanical antenna along the length and width directions and the length and thickness directions conform to an "8"-shaped radiation gain response.

3. The distributed low-frequency magneto-electromechanical antenna transceiver system according to claim 1, characterized in that: The material and polarization mode of the magnetostrictive layer in the 1:N type magnetoelectric power distributor and each magnetoelectric mechanical antenna are consistent. The material and polarization mode of the piezoelectric layer in the 1:N type magnetoelectric power distributor and each magnetoelectric mechanical antenna are consistent.

4. The distributed low-frequency magneto-electromechanical antenna transceiver system according to claim 1, characterized in that: The magnetostrictive layer in the 1:N type magnetoelectric power divider and each magnetoelectric mechanical antenna is magnetized along the length direction, and the piezoelectric layer in the 1:N type magnetoelectric power divider and each magnetoelectric mechanical antenna is polarized along the thickness direction.

5. The distributed low-frequency magneto-electromechanical antenna transceiver system according to claim 1, characterized in that: The magnetostrictive layer and the piezoelectric layer in the 1:N type magnetoelectric power divider and each magnetoelectric mechanical antenna have the same width and thickness but different lengths.

6. A distributed low-frequency magneto-electromechanical antenna transceiver system according to claim 1 or 3, characterized in that: The magnetostrictive layer is nickel zinc ferrite Ni 0.8 Zn 0.2 Fe2O4.

7. A distributed low-frequency magneto-electromechanical antenna transceiver system according to claim 1 or 3, characterized in that: The piezoelectric layer is PZT-8.

8. The design method of a distributed low-frequency magneto-electromechanical antenna transceiver system according to any one of claims 1 to 6, characterized in that: The following steps are involved: 1) Configuration 1: N-type magnetoelectric power divider: Determine the number of piezoelectric layers to be cut based on the number of communication channels required by the distributed nodes and the different drive power requirements. Measure the operating frequency range of each power output port of the magnetoelectric power divider using the magnetoelectric voltage coefficient response curve to determine the type and size of the N magnetoelectric mechanical antennas. 2) Configuring N magneto-electromechanical antennas: Adjust the size of each magneto-electromechanical antenna and change the magnitude of the applied DC bias magnetic field so that each magneto-electromechanical antenna has a consistent resonant frequency and impedance phase under a suitable DC bias magnetic field; 3) Impedance matching between a 1:N magnetoelectric power divider and N magnetoelectric mechanical antennas: Use an impedance analyzer to measure the impedance phase of each power output port of the 1:N magnetoelectric power divider and each magnetoelectric mechanical antenna. Based on the principle of impedance phase consistency, connect the piezoelectric layer leads of each magnetoelectric mechanical antenna to the power output ports of the 1:N magnetoelectric power divider to maximize the driving power of each power output port of the 1:N magnetoelectric power divider. 4) Configure N communication channels: Using the centerline of the magnetization direction of the magnetostrictive layer as the strongest radiation path, align each magneto-electromechanical antenna with the centerline of the corresponding coil along the strongest radiation path to obtain a communication channel with the strongest radiation gain; 5) Configure a distributed low-frequency magneto-electro-mechanical antenna transceiver system: Adjust the position, dimension, and angle of each communication channel to obtain a distributed magneto-electro-mechanical antenna transceiver system with different signal inputs and multi-channel outputs.

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