Flexible Drive Low-Frequency Electromagnetic Communication Mechanical Antenna

Abstract

The present invention discloses a flexible drive low-frequency electromagnetic communication mechanical antenna, which includes an electromagnetic drive device, an annular double-layer cavity, a superconducting magnet operating in a closed loop, and an orbital pulley; wherein the electromagnetic drive device provides a rotating magnetic field, the annular double-layer cavity defines the operating orbit of the superconducting magnet and maintains a low-temperature environment for the superconducting magnet, the superconducting magnet operating in a closed loop is installed in the annular double-layer cavity to provide a stable strong magnetic field, and the orbital pulley is placed between the annular double-layer cavity and the superconducting magnet to reduce the frictional force during rotational motion. The low-frequency electromagnetic communication mechanical transmitting antenna of the present invention has the advantages of small volume, stable operation, and convenient information modulation.

Description

Technical Field

[0001] The present invention belongs to the technical field of electromagnetic communication, and more specifically, relates to a flexible drive low-frequency electromagnetic communication mechanical antenna. Background Art

[0002] Since current low-frequency communication antennas must resonate with the selected frequency, this means that the size of the antenna is directly related to the frequency. This basic relationship has been the main obstacle in the low-frequency communication field for many years. For example, a 3 kHz transmitter would require an antenna equivalent to half the wavelength, that is, 5 km long. Therefore, existing ULF and VLF communication devices are costly, have a large architecture, and consume too much power. For example: To achieve communication with underwater nuclear submarines, the VLF transmitting device built by the US Navy in Maine covers an area of more than 8 square kilometers, the transmitting tower is as high as 300 meters, and the power of the power supply reaches the megawatt level.

[0003] On January 6, 2017, the Defense Advanced Research Projects Agency (DARPA) of the United States proposed the Mechanically Based Antenna (AMEBA) research project, aiming to generate electromagnetic wave signals of ultra-low frequency time-varying fields for underwater or underground communication by driving the mechanical movement of electrets or permanent magnets. Different from traditional electrically excited antenna technologies, mechanical antennas convert mechanical energy into electromagnetic energy, do not require an impedance matching network, and can achieve an efficient and miniaturized ultra-low frequency transmitter.

[0004] Regarding the current manufacturing level and material properties of electrets and permanent magnets, it is difficult for electrets to maintain a constant electric dipole moment, and the technical implementation conditions are harsh; therefore, most of the mechanical antennas in current tests use neodymium iron boron permanent magnets, but the maximum magnetic field strength of this permanent magnet does not exceed 2 T, and the strength is still limited.

[0005] Therefore, there is an urgent need for a mechanical transmitting antenna based on a new radiation source material to meet the long-distance reliable communication in "wireless communication blind areas" such as underwater, underground, and inside buildings, and has the advantages of small size, light weight, low power consumption, etc., and can solve the deficiencies of existing long-wave communication facilities. Summary of the Invention

[0006] The present invention provides a flexible drive low-frequency electromagnetic communication mechanical antenna, which can miniaturize the antenna and meet the requirements of long-distance communication such as underwater and underground.

[0007] According to one aspect of the embodiments of the present invention, a flexible drive low-frequency electromagnetic communication mechanical antenna is provided, which includes a superconducting magnet operating in a closed loop, a ring-shaped double-layer cavity, a cooling system, an electromagnetic drive device, and an orbital pulley. The superconducting magnet operating in a closed loop serves as a radiation source to generate a high-intensity and stable magnetic field and ensure that it does not quench during the mechanical rotation process. The orbital pulley fixes the superconducting magnet in the closed ring-shaped double-layer cavity and places it on a predetermined orbit, and the pulley minimizes the frictional resistance during the rotation of the superconducting magnet. The electromagnetic drive device drives the mechanical rotation of the superconducting magnet through magnetic force. According to its different structures, the electromagnetic drive device can generate a driving force by rotating or passing an alternating current, and can have the ability to adjust the frequency and speed to meet the signal requirements of different frequencies. The ring-shaped double-layer cavity and the cooling system are used in combination to provide an environment for the mechanical rotation of the superconducting magnet operating in a closed loop. The superconducting magnet is installed on the preset orbit of the ring-shaped double-layer cavity through a pulley to reduce the resistance during rotation. The cooling system generates a low-temperature environment to keep the superconducting magnet in a superconducting state and maintain its stable closed-loop operation.

[0008] The mechanical antenna using a superconductor to make the signal radiation source has a stronger magnetic field than a conventional permanent magnet, the volume of the antenna is smaller, and the radiation efficiency is higher, enabling the signal propagation distance of the existing low-frequency electromagnetic communication system to be farther and the application scenario to be wider.

[0009] Compared with the prior art, the above technical solution conceived by the present invention has the following beneficial effects:

[0010] (1) Since the flexible drive low-frequency electromagnetic communication mechanical antenna provided by the present invention uses a superconducting magnet operating in a closed loop as a radiation source, it solves the problem of insufficient magnetic field strength of conventional permanent magnets, enables the signal to propagate farther, and can penetrate deeper underwater and underground in the very low frequency case, ensuring the requirements of deep-sea electromagnetic communication;

[0011] (2) Since the flexible drive low-frequency electromagnetic communication mechanical antenna provided by the present invention adopts an isolated combined structure, the driving device and the radiation source are not driven through mechanical linkage, and the modulation signal method is flexible and diverse. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly introduced below.

[0013] Figure 1 It is a schematic diagram of the operation effect of the flexible drive low-frequency electromagnetic communication mechanical antenna provided by an embodiment of the present invention.

[0014] Figure 2 It is a structural diagram of the mechanical antenna provided by an embodiment of the present invention.

[0015] Figure 3 shows several structural diagrams of the electromagnetic drive device provided by an embodiment of the present invention. Among them, Figure 3(a) is a "cross-shaped" wound coil, which generates magnetic force by alternating the conduction of the transverse coil current and the longitudinal coil current, drives the superconducting magnet to rotate, and generates low-frequency electromagnetic signals; Figure 3(b) is a single solenoid coil. A current is passed through it, and a motor is used to mechanically rotate the solenoid coil, so as to drive the superconducting magnet to rotate and generate low-frequency electromagnetic signals; Figure 3(c) is a drive device of a three-phase induction motor. A, B, C, X, Y, and Z are three-phase stator coils. Passing a three-phase current generates a rotating magnetic field to drive the superconducting magnet to rotate and generate low-frequency electromagnetic signals. Detailed implementation mode

[0016] Operating principle: According to Maxwell's equations, the essence of electromagnetic waves is a series of mutually alternating orthogonal electromagnetic fields, and the role of an antenna is to generate the first changing electric field (or magnetic field), thereby exciting electromagnetic waves. Under the guidance of this theory, electromagnetic waves can be excited and emitted by rotating a superconducting magnet for electromagnetic communication.

[0017] As Figure 1 、 Figure 2 shown, a low-frequency electromagnetic communication mechanical antenna with flexible drive includes an annular double-layer cavity 1, a track pulley 2, an electromagnetic drive device 3, a superconducting magnet 4 operating in a closed loop, and a cooling system 5.

[0018] The superconducting magnet 4 operating in a closed loop is a radiation source, used to generate a high-intensity and stable magnetic field, and ensure that it does not quench during the mechanical rotation process.

[0019] The superconducting magnet 4 is installed on the track inside the closed annular double-layer cavity 1 through the pulley 2, and the pulley 2 should ensure that the frictional resistance is as small as possible during the rotation process.

[0020] The electromagnetic drive device 3 drives the mechanical rotation of the superconducting magnet 4 through magnetic force. According to its different structures, the electromagnetic drive device 3 can generate a driving force by rotating or passing an alternating current, and can have the ability to adjust frequency and speed to meet the signal requirements of different frequencies. Figures 3(a)-3(c) show three electromagnetic drive devices.

[0021] The benefits of the electromagnetic drive for the rotation of the superconducting magnet 4 are in two aspects: First, the superconducting magnet must be in a low-temperature environment to maintain the superconducting state, while the drive device is generally in a normal-temperature environment, and the temperature difference between the two is very large. If the drive is directly connected by structural components, the conduction heat leakage caused by the connecting structural components is serious. By using the magnetic drive method, the direct contact between the drive device and the superconducting magnet can be well avoided, thus reducing the heat leakage. Second, the mechanical antenna needs to frequently change the rotation speed. The magnetic drive is a flexible connection method. Compared with the direct rigid connection method of conventional structural components, when the rotation speed of the drive motor changes significantly, it will not cause great damage to the system.

[0022] The annular double-layer cavity 1 and the cooling system 5 are used in combination to provide an environment for the rotation of the superconducting magnet 4 operating in a closed loop. The superconducting magnet 4 is installed on the preset track of the annular double-layer cavity 1 through a pulley 2 to reduce the resistance during rotation. The cooling system 5 keeps the superconducting magnet 4 in the superconducting state to ensure its stable closed-loop operation.

Claims

1. A flexible drive low-frequency electromagnetic communication mechanical antenna, Characterized in that, Comprising: A superconducting magnet, which operates in a closed loop as a radiation source in an annular double-layer cavity to generate a high-intensity and stable magnetic field. The annular double-layer cavity defines the operating orbit of the superconducting magnet and maintains a low-temperature environment for the superconducting magnet; An electromagnetic drive device, which is located outside the annular double-layer cavity and drives the superconducting magnet to perform mechanical rotational motion in the annular double-layer cavity by magnetic force. The electromagnetic drive device generates a driving force by rotating itself or passing an alternating current; And a cooling system, which makes the superconducting magnet in a superconducting state and keeps it capable of operating stably in a closed loop.

2. The flexible drive low-frequency electromagnetic communication mechanical antenna according to claim 1, Characterized in that, The superconducting magnet is installed on the orbit in the annular double-layer cavity through a pulley.

3. The flexible drive low-frequency electromagnetic communication mechanical antenna according to claim 1, Characterized in that, The electromagnetic drive device has the ability to adjust frequency and speed to meet the signal requirements of different frequencies.

4. The flexible drive low-frequency electromagnetic communication mechanical antenna according to claim 3, Characterized in that, The coil of the electromagnetic drive device is wound in a cross shape, and magnetic force is generated by alternating the conduction of the transverse coil current and the longitudinal coil current to drive the superconducting magnet to rotate.

5. The flexible drive low-frequency electromagnetic communication mechanical antenna according to claim 3, Characterized in that, The electromagnetic drive device has a solenoid coil. A current is passed through and a motor is used to mechanically rotate the solenoid coil, thereby driving the superconducting magnet to rotate.

6. The flexible drive low-frequency electromagnetic communication mechanical antenna according to claim 3, Characterized in that, The electromagnetic drive device is a three-phase induction motor type drive device. Three-phase current is passed through the three-phase stator coils of the three-phase induction motor type drive device to generate a rotating magnetic field to drive the superconducting magnet to rotate.

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