Distributed low-frequency magnetoelectric mechanical antenna transceiving system and design method

Abstract

The invention belongs to the technical field of long-wave communication antenna systems, and discloses a distributed low-frequency magnetoelectric mechanical antenna transceiver system, which comprises a signal amplifier, a power amplifier, a 1: N-type magnetoelectric power divider and N communication channels arranged according to distributed nodes, the 1: N type magnetoelectric power divider is composed of a magnetoelectric composite material and a coil closely wound outside the magnetoelectric composite material, two wire ends of the coil are led out to serve as power input ports, and the magnetoelectric composite material is of a symmetrical structure composed of a piezoelectric layer and two magnetostriction layers bonded to the two sides of the piezoelectric layer. The piezoelectric layer is cut into N parts along the length direction and N independent power output ports are led out; the N communication channels are composed of N magnetoelectric mechanical antennas and N coils which are correspondingly arranged, and a power output port of each 1: N type magnetoelectric power divider is connected with a piezoelectric layer lead in each magnetoelectric mechanical antenna so as to provide a radiation excitation source.

Description

Technical Field

[0001] The 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] The wavelength corresponding to low-frequency / very low-frequency communication is relatively long, and can easily penetrate metal, soil, rock and salt water (10-20m). It has outstanding advantages such as long transmission distance, strong penetration and strong anti-electromagnetic pulse interference ability, and can be widely used in submarine communication, long-distance communication, long-distance navigation, wireless heartbeat frequency detector, geophysical research and disaster relief. However, the size of the long-wave radio antenna that transmits low-frequency / very low-frequency signals is restricted by its wavelength. In theory, when the antenna length is 1 / 4 of the wavelength of the radio wave signal, the antenna's transmission and reception conversion efficiency reaches the highest, which leads to the need for a land-based transmission base station of the very low-frequency communication system to have a large antenna array that stretches for miles. Therefore, countries are also working hard to improve and solve the current difficulties faced by long-wave antennas in terms of miniaturization, portability and low power. In 2017, the Defense Advanced Research Projects Agency Microsystems Office (DARPA-MTO) of the United States Department of Defense first released the AMEBA (AMEchanically Based Antenna) project plan task book organized and developed by Dr. Troy Olsson. The plan focuses on finding a revolutionary innovative solution for mechanically driven antenna transmitters to generate radio frequency signals at carrier frequencies below 30kHz, and strives to subvert the coupling mechanism of the electromagnetic waves generated by the traditional antennas that rely on the oscillation circuit, and explore new methods to generate oscillating electromagnetic waves through mechanical vibration. So far, according to the different mechanical vibration generation, electromagnetic wave radiation principles and implementation schemes, mechanical antennas can be mainly divided into two categories: "mechanical motion type" low-frequency mechanical antennas represented by electret mechanical antennas and permanent magnet mechanical antennas, and "acoustically driven type" 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 antenna relies on the strong magneto-electric coupling of the piezomagnetic / piezoelectric phase, compared with the electret / permanent magnet rotating mechanical antenna and the piezoelectric mechanical antenna, and combines the high efficiency and precision of the "electric drive" of piezoelectric materials and the controllability of magnetic dipole modulation, and is considered to be a key technology for the development of very low frequency communication technology. However, the 360° directivity of a single magneto-electromechanical antenna shows an "8"-shaped normalized directional radiation characteristic. Due to its significant anisotropy, the magneto-electromechanical antenna has good directivity, but basically does not generate outward electromagnetic radiation at angles of 90° and 270°. Therefore, a single magneto-electromechanical antenna has a dead angle in radiation intensity, and is only strongest along the length direction, and cannot achieve dead angle-free and full area coverage. Summary of the invention

[0004] In view of the technical problem that existing magneto-electric antennas cannot achieve zero-dead-angle and full-area coverage, the present invention provides a distributed low-frequency magneto-electro-mechanical antenna transceiver system. By adjusting the position, distance and dimension of the magneto-electro-mechanical antenna, any 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, including 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 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 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-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-power distributor 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 cuts of the piezoelectric layer according to the number of communication channels required by the distributed nodes and the different driving power requirements; measure the operating frequency range of each power output port of the magnetoelectric power divider through the magnetoelectric voltage coefficient response curve, and 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 changing the size of the external 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) Configure impedance matching between a 1:N type magnetoelectric power divider and N magnetoelectric mechanical antennas: measure the impedance phase of each power output port of the 1:N type power divider and each magnetoelectric mechanical antenna by using an impedance analyzer; according to the impedance phase consistency principle, connect the piezoelectric layer lead in each magnetoelectric mechanical antenna to each power output port of the 1:N type magnetoelectric power divider accordingly, so that the driving power of each power output port of the 1:N type magnetoelectric power divider is maximized;

[0019] 4) configuring N communication channels: taking the center line of the magnetization direction of the magnetostrictive layer as the strongest radiation path, aligning 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 different distributed magneto-electro-mechanical antenna transceiver systems with signal input and multi-channel output.

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

[0022] The present invention utilizes 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 the magnetostrictive layer of each mechanical antenna. The signal is input to the magnetoelectric power divider and the input power is distributed to multiple communication channels according to the required proportion. The magnetoelectric mechanical antenna can be placed at different positions, distances, and dimensions to achieve arbitrary spatial distribution of the communication system to meet different requirements 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 The communication principle and structural diagram of the distributed low-frequency magneto-electromechanical antenna transceiver system in Example 1.

[0025] Figure 3 This 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 group of graphs showing positive magnetoelectric voltage coefficient curves of two power output ports of the 1:2 type magnetoelectric power divider in Example 1 under different DC biases.

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

[0028] Figure 6 This is a group 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 1 and 2 are the radiation patterns of the magneto-electromechanical antenna MA1 in Example 1 at 57500 Hz in three coordinate planes.

[0030] Figure 8 1 and 2 are the radiation patterns of the magneto-electromechanical antenna MA2 in Example 1 at 57500 Hz in three coordinate planes.

[0031] Fig. 9 This is a loss test experiment diagram of the induced magnetic field generated by the magneto-electromechanical antennas MA1 and MA2 at 57500 Hz in Example 1, which varies with distance.

[0032] Fig.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] Fig.11 This is a modulation and demodulation timing diagram 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 the present invention. Unless otherwise specified, the technical means used in the examples are conventional means known to those skilled in the art. The test methods in the following examples are conventional methods unless otherwise specified.

[0035] Figure 1 The communication original diagram and substructure diagram of the distributed low-frequency magneto-electro-mechanical antenna transceiver system of the present invention include a signal amplifier, a power amplifier, a 1:N type magneto-electro-mechanical power distributor and N communication channels arranged according to 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, two wire ends of the coil are led out as power input ports, the magnetoelectric composite material is a symmetrical structure composed 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-power distributor 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 out from the silver electrode surfaces on the upper side and lower side of each piezoelectric layer of the magnetoelectric power distributor, and 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, and 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 is used as a transmitting unit, and the coil is used as a receiving unit. The two always appear in pairs. By combining them one by one, the distributed long-wave communication requirements deployed at different positions, different dimensions, and different angles are met to form 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. Under 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 further 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 of each port, and has a good impedance match 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 parts of 1:2:3, then the power ratio of the corresponding three communication channels is 1:2:3.

[0041] The frequency response of 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 directional diagrams 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 directional diagrams along the width and thickness directions are close to the isotropic radiation gain.

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

[0043] Example 1

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

[0045] Production 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), sintered into blocks by solid-state method, 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 according to the effective electrode area ratio of 1:1. The upper and lower silver electrode surfaces of each piezoelectric layer are used as the power output port I (Port 1) and power output port II (Port 2) of the magnetoelectric power divider. 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 wire ends of the coil are led out as power input ports to obtain a 1:2 type magnetoelectric power divider. Its structure and principle are shown as follows Figure 2 (c) as shown.

[0046] Making communication channel: The material used for magnetostrictive layer is Ni 0.8 Zn 0.2 Fe2O4, length × width × height = 37mm × 6mm × 1mm, magnetized along the length direction (L). The piezoelectric material layer is PZT-8, length × width × height = 40mm × 6mm × 1mm, polarized along the thickness direction (T). The magnetostrictive layer is bonded to the upper and lower sides of the piezoelectric layer with epoxy resin to obtain the magneto-electromechanical antennas MA1 and MA2. The receiving coil radius corresponding to the magneto-electromechanical antenna is 1.96cm, the length is 5.8cm, and the internal resistance is 9Ω.

[0047] Figure 2(a) is 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 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 drawn out on the upper and lower sides of each piezoelectric layer. The power divider converts the input power and divides it equally to Port1 and Port2 outputs, which are connected to magneto-mechanical antennas MA1 and MA2 respectively. MA1 and MA2 generate alternating magnetic fields through the inverse magneto-electric effect and radiate them, which are captured by the receiving coil to obtain the output V out1 and V out2 , each magneto-electromechanical antenna is coaxially placed with the receiving coil so that the communication channel works in the strongest radiation path, forming the communication channel 1 and channel 2 of the system.

[0048] exist Figure 2 In the structural diagram shown in (b), the input signal is evenly torn by the effective electrode area ratio of 1:1 and output from Port1 and Port2 respectively. MA1 and MA2 are coaxially aligned along the center line with their corresponding coils to form two communication channels, which are independently excited and supplied by Port1 and Port2 of the 1:2 power divider. By changing the angle, distance and dimension between the communication channels composed of MA1 and MA2 and their corresponding coils, the arbitrary spatial distribution of the communication system is achieved.

[0049] Figure 3 The impedance phase diagram of the two power output ports of the 1:2 type magnetoelectric power divider in this embodiment. The measuring device includes an impedance analyzer (model: KEYSIGHT E4990A) and a desktop computer with its corresponding software system. The measured impedance phase curves of Port1 and Port2 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 group of graphs of positive magnetoelectric voltage coefficient curves of two power output ports of the 1:2 type magnetoelectric power divider in this embodiment under different DC biases. The test device for the positive magnetoelectric voltage coefficient curve of each port includes: a phase-locked amplifier (model: Zurich MFLI-500kHz), a desktop computer equipped with its 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 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 size, the amplitude-frequency characteristic group of the output voltage of the two output ports under different DC biases with frequency can be measured.

[0051] Figure 5 : is a group of diagrams showing the impedance phase, the inverse magnetoelectric voltage coefficient under different DC bias and the 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 magneto-electromechanical antennas MA1 and MA2. The test device and principle are similar to Figure 2 The tests on each port of the magneto-electric power divider are consistent. Figure 5 (b) and Figure 4 (f) is the reverse magnetoelectric voltage coefficient curve of MA1 and MA2 measured by placing them inside a coil (radius 1.96cm, length 5.8cm, internal resistance 9Ω) under different DC bias. The test device and principle are the same as Figure 3 The tests of the ports of the magneto-electric 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 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 the 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 biases is 9.21 measured at 41Oe; the maximum inverse magnetoelectric voltage coefficient of MA2 under different DC biases is 7.24 measured at 31Oe. Figure 5 (a) and Figure 5 (e) When the measured frequency is 57500Hz, the impedance of MA1 is 10867Ω and the phase is 31.7 degrees; the impedance of MA2 is 9440Ω and the phase is 69.8 degrees. According to the impedance approximation matching method, Port1 is connected to MA1; Port2 is connected to MA2. Considering the loss problem of impedance transformation, the direct connection method is used to build the system when the impedance difference between the magnetoelectric power divider port and the mechanical antenna is small.

[0052] Figure 6 The figure shows the conversion efficiency, output voltage and port voltage ratio of the two power output ports of the 1:2 type magnetoelectric power divider in this embodiment at 57500Hz as a function of load resistance. The test device includes: a signal generator (model: Agilent33250A), a 200Ω resistor, a sliding variable resistance box (model: Shanghai Dongmao Technology ZX21F), an oscilloscope (model: Tektronix TDS2012B), a data acquisition board (model: NI instruments PCI-6250), a BNC connector (NIinstruments BNC-2110), an adjustable DC bias magnetic guide rail and a desktop computer with its corresponding Labview software system. During the test, the signal generator is used as an input source, set to a sine wave with an amplitude of 200mV and a frequency of 57500Hz (operating point), and its output port is connected in series with a 200Ω resistor and then connected to the coil of the power divider. 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, the total input power of the magnetoelectric power divider can be obtained ( Represents the phase difference angle). 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 obtained 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 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 get the output port voltage ratio of the magnetoelectric power divider as a function of 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 of this embodiment at 57500Hz in three coordinate planes. The test device includes a coil (radius 1.96cm, length 5.8cm, internal resistance 9Ω) as a receiving antenna, a phase-locked amplifier (model: Zurich MFLI-500kHz), and a desktop computer with its corresponding Labone software system. The excitation voltage is set to 282.8mV and the DC bias is 41Oe. The response values ​​of the magneto-electromechanical antenna in each plane are measured, and the data are 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 direction diagram, Figure 7 (d) is the xy plane directional diagram.

[0054] Figure 8 The radiation pattern of the magneto-electromechanical antenna MA2 in this embodiment at 57500Hz in three coordinate planes. The test device includes a coil (radius 1.96cm, length 5.8cm, internal resistance 9Ω) as a receiving antenna, a phase-locked amplifier (model: Zurich MFLI-500kHz), and a desktop computer with its corresponding Labone software system. The excitation voltage is set to 282.8mV and the DC bias is 31Oe. The response value of the magneto-electromechanical antenna in each plane is measured, and the data is 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 direction diagram, Figure 8 (d) is the xy plane directional diagram.

[0055] Fig. 9The figure is a test experiment of the loss of the induced magnetic field generated by the magneto-electromechanical antennas MA1 and MA2 at 57500Hz as the distance changes. The test device includes a coil (radius of 1.96cm, length of 5.8cm, internal resistance of 9Ω) as a receiving antenna, a phase-locked amplifier (model: Zurich MFLI-500kHz), a desktop computer with its corresponding Labone software system, a power amplifier (model: Aigtek ATA-2041High Voltage Amplifer), and an oscilloscope (model: Tektronix TDS2012B). During the test, the output port of the phase-locked amplifier is connected to the input port of the power amplifier, and the output peak voltage is set to 2V and the frequency is 57500Hz (operating point) of the sine wave. The voltage and current monitoring ports of the power amplifier are respectively connected to the two ports of the oscilloscope, and the input power is obtained by multiplying them. By changing the amplification factor of the power amplifier, the input power is limited to 200mW. 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 to be tested, 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 captures the voltage response of the corresponding distance and converts the voltage value into an induced magnetic field. Under the condition of fixed input power, the induced magnetic field of MA1 and MA2 changes with distance as shown below: Fig. 9 (a) and Fig. 9 (b) as shown.

[0056] Fig.10The figure is the radiation response diagram of the induced magnetic field and input power generated by the magneto-electro-mechanical antennas MA1 and MA2 at 57500Hz as the driving voltage changes. The test device includes a coil (radius of 1.96cm, length of 5.8cm, internal resistance of 9Ω), a phase-locked amplifier (model: Zurich MFLI-500kHz), a desktop computer with its corresponding Labone software system, a power amplifier (model: Aigtek ATA-2041High Voltage Amplifer), and an oscilloscope (model: Tektronix TDS2012B). During the test, the DC bias of MA1 is set to 41Oe, and the DC bias of MA2 is set to 31Oe. The distance between the coil and the mechanical antenna is fixed at 10cm. The phase-locked amplifier is set to output a sine wave with a peak voltage of 3V and a frequency of 57500Hz (operating point). The power amplifier is set to provide the magneto-electro-mechanical antenna with a step size of 3V in the range of 0 to 120V. 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. Fig.10 (a) and Fig.10 (b) as shown.

[0057] Fig.11 The modulation and demodulation timing diagram 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 to 10cm, and the center line of the mechanical antenna is aligned with the center line of the receiving coil. The signal generator is set to output a fundamental wave of 10Hz square wave, a carrier wave of 57500Hz frequency, an amplitude of 10V sine wave, and a depth of 100% amplitude shift keying modulation wave, and connected to the coil lead input of the power divider. 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 coils and displayed on the oscilloscope as shown below. Fig.11 (a) and Fig.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, other implementation methods can certainly be easily made by replacement or modification based on the technical contents 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 magneto-electric power distributor and N communication channels arranged according to distributed nodes; The 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 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 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.

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

4. A 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 distributor and each magnetoelectric mechanical antenna is magnetized along the length direction, and the piezoelectric layer in the 1:N type magnetoelectric power distributor and each magnetoelectric mechanical antenna is polarized along the thickness direction.

5. A 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 layer cuts based on the number of communication channels required by the distributed nodes and the different driving power requirements; measure the operating frequency range of each power output port of the magnetoelectric power divider through the magnetoelectric voltage coefficient response curve, and determine the type and size of the N magnetoelectric mechanical antennas; 2) Configure N magneto-electro-mechanical antennas: adjust the size of each magneto-electro-mechanical antenna and change the size of the external 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; 3) Configure the impedance matching between the 1:N type 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 type power divider and each magnetoelectric mechanical antenna; According to the impedance phase consistency principle, the piezoelectric layer lead in each magnetoelectric mechanical antenna is connected to each power output port of the 1:N type magnetoelectric power divider accordingly, so that the driving power of each power output port of the 1:N type magnetoelectric power divider is maximized; 4) Configure N communication channels: take the center line of the magnetization direction of the magnetostrictive layer as the strongest radiation path, and 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; 5) Configure a distributed low-frequency magneto-electro-mechanical antenna transceiver system: adjust the position, dimension and angle of each communication channel to obtain different distributed magneto-electro-mechanical antenna transceiver systems with signal input and multi-channel output.

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