Multi-unit very-low-frequency transmitting antenna system and tuning method thereof

Abstract

The invention provides a multi-unit very-low-frequency transmitting antenna system and a tuning method thereof, and belongs to the technical field of very-low-frequency transmitting antennae, and the multi-unit very-low-frequency transmitting antenna system comprises a plurality of antenna units, a plurality of tuning pavilions, a plurality of low-voltage feeder lines, a transmitter and a plurality of ground nets, the plurality of tuning pavilions are respectively positioned near the central position of each group of antenna units, each tuning pavilion consists of a plurality of tunable coils with the same structure, and the tuning pavilions are connected with the root parts of the antenna units; the plurality of low-voltage feeders are respectively connected with the transmitter and the plurality of tuning booths, the transmitter is located at the geometric center of the antenna array formed by the plurality of antenna units, and the transmitter is connected with the low-voltage feeders through the shunt device and the high-voltage isolation switch; the plurality of ground nets are respectively laid by taking the plurality of antenna units as the center, each ground net is composed of a plurality of local ground nets which are laid in a radial shape, and the plurality of ground nets are connected through metal ground net wires or are kept independent and not connected. According to the invention, the complexity and difficulty of antenna design and construction are obviously reduced, and the dependence on the terrain of an antenna array is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of very low frequency transmitting antenna, in particular to a multi-unit very low frequency transmitting antenna system and a tuning method thereof. BACKGROUND

[0002] Very low frequency communication refers to a communication mode using radio waves with a frequency in the range of 3-30 kHz for long-distance signal transmission. The waves in this frequency band have the advantages of stable propagation, strong penetration ability and good anti-interference performance, and can be applied to the communication of ocean surface ships.

[0003] Traditional very low frequency transmitting antennas usually adopt T-shaped iron tower antennas, umbrella-shaped iron tower antennas and valley antennas. These antennas all use the structure of vertical antennas, and have the problem of large structure. Taking the Jim Creek antenna in the United States as an example, as a valley antenna, it is composed of 10 top-loaded lines and 12 support towers with a height of 200 feet. The support towers support the top-loaded lines with a length of 5640-8700 feet in Z zigzag form above the valley between two mountains. The northwest corner antenna in Australia is a single group of thirteen-tower umbrella-shaped antenna, which has 13 support towers, the highest of which reaches a height of 387m, and the radius of the umbrella-shaped antenna reaches 1260m. The single group of antennas occupies an area of 5 square kilometers.

[0004] The existing very low frequency transmitting station antenna has the following defects: The structure is complex, resulting in a long construction period; the antenna occupies a large scale of land, and has very strict requirements for the terrain, such as the valley antenna which requires a large enough valley depth, and the iron tower antenna which needs a complete and flat site.

[0005] In order to reduce the restriction of the very low frequency transmitting antenna on the antenna site and reduce the complexity of the antenna structure design and construction, effective measures need to be taken to reduce the size of the antenna. However, the reduction of the size of the antenna will bring some problems, such as increasing the voltage at the root and bottom of the antenna, reducing the power of the transmitting system, and further reducing the communication support distance of the transmitting station. SUMMARY

[0006] The present application provides a multi-unit very low frequency transmitting antenna system and a tuning method thereof to overcome the defects of the prior art. The system forms an array through spatial coupling of multiple units and adopts a flexible and reliable feeding mode to enhance the anti-attack capability of the very low frequency transmitting antenna array.

[0007] The present application provides a multi-unit very low frequency transmitting antenna system and a tuning method thereof which are completely different in structure and have superior performance.

[0008] In a first aspect, the present invention provides a multi-element very low frequency transmitting antenna system, comprising: multiple antenna elements, multiple tuning pavilions, multiple low-voltage feeders, a transmitter, and multiple grounding grids; The multiple antenna elements are vertical antennas with the same structure and equal amplitude and phase excitation. The plurality of tuning pavilions are located near the center of each group of antenna elements. Each tuning pavilion is composed of a plurality of tunable coils with the same structure and is connected to the root of the antenna element. The plurality of low-voltage feeders are respectively connected to the transmitter and the plurality of tuning booths, and the low-voltage feeders are composed of two concentric metal cylinders. The transmitter is located at the geometric center of the antenna array composed of the multiple antenna elements, and the transmitter is connected to the low-voltage feeder through a splitter and a high-voltage disconnect switch; The multiple grounding grids are laid out with the multiple antenna units as the center. The grounding grids are composed of multiple radially laid local grounding grids. The multiple grounding grids are connected by metal grounding grid wires or remain independent and unconnected.

[0009] According to the multi-element very low frequency transmitting antenna system, the horizontal distance between the centers of the multiple antenna elements is no greater than one-tenth of the operating wavelength, and the height of the multiple antenna elements is one-thirtieth of the operating wavelength.

[0010] According to the multi-element very low frequency transmitting antenna system, the antenna element is a self-supporting metal tower antenna with its bottom insulated from the ground.

[0011] According to the multi-element very low frequency transmitting antenna system, the grounding wire is made of copper wire with good conductivity.

[0012] According to the multi-element very low frequency transmitting antenna system, the transmitting room includes a splitter and multiple high-voltage disconnect switches, each of which is connected to a low-voltage feeder.

[0013] Secondly, the present invention provides a tuning method for any of the above-mentioned multi-element very low frequency transmitting antenna systems, the method comprising the following steps: The transmitter excites the plurality of antenna elements through the low-voltage feeder and the tuning pavilion; The transmitter achieves two power supply modes—full-feed tuning mode and multi-antenna multi-tuning mode—by controlling the on / off state of the high-voltage disconnect switch. In the fully fed tuning mode, the transmitter excites all the antenna elements in parallel through the low-voltage feed line; In the multi-antenna multi-tuning mode, the transmitter only excites the group of antenna units connected thereto through the low-voltage feeder, and the rest of the antenna units are excited through spatial coupling.

[0014] According to the tuning method, comprising: The transmitter excites all the antenna units in parallel through the low-voltage feeder, so that the input current of each antenna unit is equal.

[0015] According to the tuning method, comprising: In the multi-antenna multi-tuning mode, the transmitter only excites the group of antenna units connected thereto through the low-voltage feeder, and the rest of the antenna units are excited through spatial coupling.

[0016] According to the tuning method, the transmitter reasonably distributes power to each antenna unit through the shunt device, ensuring that each antenna unit obtains appropriate excitation power, thereby improving the signaling effect of the entire antenna system.

[0017] According to the tuning method, the transmitter switches between different working modes through the on-off control of the high-voltage disconnector, to adapt to different signaling requirements and environmental conditions.

[0018] The multi-unit VLF signaling antenna system and the tuning method thereof provided by the present application have the following beneficial effects compared with the prior art: The multi-unit VLF signaling antenna system of the present application divides a single large antenna into multiple small-scale single antenna elements, and sets a tuning booth at the root of each antenna unit and a transmitter in the middle of the antenna array, to realize two feeding modes of full feeding tuning mode and multi-antenna multi-tuning mode. The present application significantly reduces the complexity of antenna design and construction, reduces the dependence on the terrain of the antenna site, and enhances the anti-attack capability of the VLF signaling antenna array. By using antenna units with equal amplitude and in-phase excitation and tuning booths with the same structure, and by connecting the transmitter and the tuning booth through the low-voltage feeder, the present application not only improves the flexibility and reliability of the system, but also retains the low-loss characteristics of the traditional ground net through the design of the local radiating ground net, while reducing the strict requirements for site flatness. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0020] Fig. 1is the overall structure schematic diagram of the multi-unit very low frequency signaling antenna system provided by the application; Fig. 2 is the structure schematic diagram of the full feeding tuning mode of the multi-unit very low frequency signaling antenna system provided by the application; Fig. 3 is the structure schematic diagram of the multi-unit very low frequency signaling antenna system provided by the application; In the figure: 1. Antenna unit, 2. Tuning pavilion, 3. Low-voltage feeder, 4. Very low frequency signaling machine, 5. Ground net, 41. Shunt device, 42. High-voltage isolating switch. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the present application more clear, the technical scheme in the present application will be described clearly and completely below in combination with the drawings in the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0022] It should be noted that in the description of the embodiments of the present application, the terms "comprise", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitation, the element defined by the sentence "comprises a" does not exclude the presence of other identical elements in the process, method, article or device comprising the element. The terms "upper", "lower" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise explicitly specified and limited, the terms "mount", "connect", "connect" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0023] The multi-unit very low frequency signaling antenna system provided by the application comprises: a plurality of antenna units, a plurality of tuning pavilions, a plurality of low-voltage feeders, a signaling machine and a plurality of ground nets. The multiple antenna units are in the form of equal-amplitude and in-phase excited vertical antennas with identical structures; The multiple tuning towers are respectively located near the center of each group of antenna units, and each tuning tower is composed of multiple identical adjustable coils, and the tuning towers are connected to the roots of the antenna units; The multiple low-voltage feeders are respectively connected to the transmitters and the multiple tuning towers, and the low-voltage feeders are composed of two concentric metal cylinders; The transmitter is located at the geometric center of the antenna array composed of the multiple antenna units, and the transmitter is connected to the low-voltage feeders through a shunt device and a high-voltage disconnector; The multiple ground nets are respectively laid around the multiple antenna units, and each ground net is composed of multiple radiationally laid local ground nets, and the multiple ground nets are connected by metal ground net wires or kept independent and unconnected.

[0024] In one embodiment of the present application, a multi-unit very low frequency transmitting antenna system is constructed to achieve efficient and flexible communication functions. The system covers multiple antenna units that work in equal-amplitude and in-phase excited mode and have basically identical vertical antenna structures. In order to achieve effective tuning of each antenna unit, multiple tuning towers are arranged near the center of each antenna unit. Each tuning tower is composed of multiple identical adjustable coils, and the tuning towers are closely connected to the roots of the antenna units to ensure accurate transmission and tuning of signals.

[0025] In order to effectively transmit signals from the transmitter to each tuning tower, multiple low-voltage feeders are provided. These low-voltage feeders are composed of two concentric metal cylinders with good conductivity, ensuring the stability and efficiency of signal transmission. The transmitter is placed at the geometric center of the antenna array composed of the multiple antenna units, and is connected to the low-voltage feeders through a shunt device and a high-voltage disconnector.

[0026] In addition, in order to improve the overall performance and adaptability of the antenna system, multiple ground nets are respectively laid around each antenna unit. These ground nets are composed of multiple radiationally laid local ground nets, and can be connected by metal ground net wires or kept independent and unconnected according to actual needs, which not only reduces ground loss, but also improves the radiation efficiency of the antenna system, and enhances the adaptability of the system to different terrains and environments.

[0027] In practical applications, the system can realize its functions in various ways. For example, the antenna units can adopt different forms of vertical antenna structures, such as self-standing metal tower antennas with bottom-to-ground insulation, or other antenna forms with similar characteristics.

[0028] In an alternative embodiment, the height of the antenna unit is small relative to the operating wavelength, for example, one-thirtieth of the operating wavelength (30 kHz).

[0029] Preferably, the antenna unit is a self-supporting tower of a metal insulated from the ground, and can also be a T-shaped, g-shaped or umbrella-shaped antenna with a top loading.

[0030] Preferably, the horizontal distance between the centers of the antenna units is not greater than one-tenth of the operating wavelength (30 kHz). At this distance, the energy coupling between the antenna units is not significantly affected by the surrounding terrain, and the performance of the antenna array remains essentially unchanged when the shape of the antenna structure is maintained, thereby reducing the sensitivity to the antenna site.

[0031] The tunable coil in the tuning pavilion can be adjusted according to different operating frequencies and environmental conditions to achieve optimal tuning results.

[0032] The tuning pavilion is composed of multiple tunable coils with the same structure located near the center of each group of antenna units. Preferably, the tuning pavilion is connected to the root of the metal tower insulated from the ground.

[0033] The material and structure of the low-voltage feeder can also be selected according to specific needs, such as using different metal materials with different conductivity to optimize signal transmission efficiency. The low-voltage feeder is a coaxial feeder composed of two concentric inner and outer metal cylinders with good conductivity. Preferably, the length of the low-voltage feeder between the transmitter room and the tuning pavilion is equal.

[0034] The location and connection method of the transmitter can also be adjusted according to the specific layout of the antenna array to ensure uniform distribution and efficient transmission of signals. The transmitter is connected to the tuning pavilion at the root of multiple antenna units through the low-voltage feeder, and preferably the transmitter is located at the geometric center of the antenna array composed of multiple antennas.

[0035] Preferably, the transmitter room includes a shunt device and multiple high-voltage disconnectors, and the multiple high-voltage disconnectors are respectively connected to a low-voltage feeder. The transmitter is connected to the low-voltage feeder through the shunt device and the high-voltage disconnector, and preferably a set of high-voltage disconnectors is provided for each low-voltage feeder.

[0036] The design and laying method of the ground net can also be optimized according to the terrain and environmental conditions, such as using local ground nets of different shapes and sizes, or using ground net wires of different materials to improve the performance and adaptability of the system. Specifically, the ground net can be composed of multiple local ground nets radiating from the center of the antenna unit, and the local ground nets can be connected by metal ground net wires or not connected.

[0037] The multi-element very low frequency (VLF) transmitting antenna system of the present invention can not only effectively solve the complexity and limitations brought about by traditional large single antenna structures, but also reduce the complexity and difficulty of antenna design and construction, reduce the dependence on antenna site terrain, and enhance the antenna system's resistance to attacks while ensuring communication performance.

[0038] Based on the above-described multi-element very low frequency (VLF) transmitting antenna system, the present invention also provides a tuning method applicable to any of the above-described multi-element VLF transmitting antenna systems, the method comprising the following steps: The transmitter excites the plurality of antenna elements through the low-voltage feeder and the tuning pavilion; The transmitter achieves two power supply modes—full-feed tuning mode and multi-antenna multi-tuning mode—by controlling the on / off state of the high-voltage disconnect switch. In the fully fed tuning mode, the transmitter excites all the antenna elements in parallel through the low-voltage feed line; In the multi-antenna multi-tuning mode, the transmitter excites only the group of antenna elements connected to it through the low-voltage feeder, while the other antenna elements are excited through spatial coupling.

[0039] The direct excitation tuning and indirect excitation tuning of the antenna elements are controlled by a high-voltage disconnect switch.

[0040] In the multi-tuned feeding process of a multi-element very low frequency (VLF) transmitting antenna, all high-voltage disconnect switches are closed, and each tuning pavilion is directly excited for tuning. The transmitter provides feed excitation to all antenna elements via a low-voltage feed line in parallel. Due to the close spacing between antenna elements, the radiation resistance of each element is equal to the mutual coupling resistance induced by other elements. With full feed, the resistance of an antenna element is n times its own radiation resistance (where n is the number of antenna elements), reducing the input current of a single antenna element and thus simplifying the tuning pavilion design. For each antenna element, the ground grid size remains unchanged, and the ground loss resistance remains constant. Because the antenna resistance increases while the loss resistance remains constant, the radiation efficiency of the antenna element is significantly improved.

[0041] Compared to the fully fed tuning mode, the multi-antenna multi-tuning mode has the following significant advantages: On the one hand, reliability is improved because each antenna element can be directly excited, and the system can still work when the low-voltage feeder is damaged, resulting in higher reliability; On the other hand, cost optimization is achieved. While maintaining the antenna system performance, only one set of low-voltage feeder 3 needs to be built, and other units can work through coupling to reduce the system construction cost.

[0042] Furthermore, in order to provide a clearer explanation of the technical solution of the present invention, the following description is provided in conjunction with... Figs. 1 to 3The technical solution of the present invention will be further described in conjunction with a specific embodiment.

[0043] like Fig. 1 As shown, the multi-element very low frequency (VLF) transmitting antenna system of this invention consists of antenna element 1, tuning pavilion 2, low-voltage feeder 3, VLF transmitter 4, ground network 5, etc.

[0044] The multi-element antenna array consists of four identical antenna elements 1, all with equal amplitude and in-phase excitation. Each antenna element 1 is a monopole antenna, specifically a self-supporting metal tower antenna with its base insulated from the ground. The antenna height is 250m–350m, which is one-thirtieth of the operating wavelength. The horizontal distance between the centers of each antenna element 1 is 1000m, which is one-tenth of the operating wavelength.

[0045] Beneath each antenna group, a radial ground network 5 centered on that unit is laid, using highly conductive copper wires. The radial ground networks of each unit can be connected by metal wires to form a unified large ground network, or they can remain independent and unconnected.

[0046] Near the center of each antenna element 1, a set of identical tunable coils is constructed to form a tuning pavilion 2. Each tuning pavilion 2 corresponds to one antenna element 1, and each tuning pavilion 2 is connected to one antenna element 1.

[0047] The multi-element transmitting antenna system has a transmitting room built at the center of the antenna array, housing a very low frequency (VLF) transmitter 4. Four sets of low-voltage feed lines 3 are constructed between the transmitter and each tuning pavilion. Each low-voltage feed line 3 is a coaxial feed line composed of two concentric copper cylinders. The lengths of each set of low-voltage feed lines 3 should be as equal as possible, with a length error not exceeding 10m.

[0048] Inside the transmitter room, in addition to the very low frequency transmitter 4, a splitter 41 and four high-voltage disconnect switches 42 are also installed. Each set of high-voltage disconnect switches 42 is connected to a low-voltage feeder 3. By controlling the on / off state of the high-voltage disconnect switches 42, direct or indirect excitation of the antenna element 1 can be achieved. The spacing between antenna elements is one-tenth of the operating wavelength, and the spatial coupling between antenna elements is strong. By controlling the on / off state of the high-voltage disconnect switches, full-feed tuning mode and multi-antenna multi-tuning mode can be achieved.

[0049] like Fig. 2The diagram illustrates a fully fed tuning mode with four antenna elements. The very low frequency transmitter 4 excites all four antenna elements 1 in parallel via a low-voltage feeder 3, and all high-voltage disconnect switches 42 inside the transmitter room are closed. Due to the close spacing between the antenna elements, the radiation resistance of each element is equal to the mutual coupling resistance induced by the other individual antenna elements; the resistance of the fully fed antenna element is four times its own radiation resistance. This reduces the input current of a single antenna element and decreases the current in the tuning pavilion coil, simplifying the tuning pavilion design. The antenna element ground grid size remains unchanged, and the ground loss resistance remains constant. The increased antenna resistance while maintaining a constant loss resistance significantly improves the radiation efficiency of the antenna elements.

[0050] like Fig. 3 The diagram illustrates a multi-antenna, multi-tuning mode with four antenna elements. In the transmitter unit, only one set of high-voltage disconnect switches 42 is closed, while the others are disconnected. The very low frequency transmitter 4 excites the connected antenna element 1 via the low-voltage feeder 3, meaning the corresponding tuning pavilion is directly excited and tuned. The other three antenna elements are excited through spatial coupling, and their corresponding tuning pavilions require tuning grounding. Similar to the fully fed mode, the radiation resistance of each antenna element is equal to the mutual coupling resistance induced by other individual antenna elements. The total resistance of each antenna element is four times its own radiation resistance. This reduces the single-group input current, simplifying the tuning pavilion design, and improving the antenna's radiation efficiency in the same way as the fully fed mode.

[0051] The multi-element very low frequency transmitting antenna system and its tuning method provided by this invention have the following advantages compared with the prior art: 1) This invention breaks through the large single antenna structure, decomposes the very low frequency antenna into n (n≥2) independent antenna elements with the same structure, and forms an array through spatial coupling. This significantly reduces the complexity of antenna design and construction, greatly reduces the dependence on ultra-large sites and special terrains (such as deep valleys), and allows the antenna array to be flexibly deployed in conventional sites.

[0052] 2) This invention adopts a local radial grounding grid design, in which each unit grounding grid can be laid independently or interconnected by wires. This design retains the low-loss characteristics of traditional grounding grids while reducing the strict requirements on site flatness.

[0053] 3) This invention features a flexible and reliable feeding mode, employing a distributed deployment of the tuning pavilion and a centralized feeding arrangement design. It supports both full-feed tuning mode and multi-antenna multi-tuning mode, increasing the antenna system's operating modes and improving reliability and survivability. Both modes reduce the current flowing through the antenna elements and tuning pavilion, alleviating the design complexity of the tuning coils.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0055] For example, individual ceramic insulator units can have skirts to increase creepage distance; the pre-tightening mechanism can also adopt a center-through tie rod; the number of insulator layers and the quantity per layer can be adjusted according to actual load and voltage requirements. All these variations and modifications should fall within the scope of protection defined by the appended claims.

Claims

1. A multi-element very low frequency (VLF) transmitting antenna system, characterized in that, include: Multiple antenna units (1), multiple tuning booths (2), multiple low-voltage feeders (3), one transmitter (4), and multiple grounding grids (5); The multiple antenna elements (1) are vertical antennas with the same structure and equal amplitude and phase excitation; The multiple tuning pavilions (2) are located near the center of each group of antenna units (1). Each tuning pavilion (2) is composed of multiple tunable coils with the same structure. The tuning pavilion (2) is connected to the root of the antenna unit (1). The plurality of low-voltage feeders (3) are respectively connected to the transmitter (4) and the plurality of tuning pavilions (2), and the low-voltage feeders (3) are composed of two concentric metal cylinders; The transmitter (4) is located at the geometric center of the antenna array composed of the plurality of antenna elements (1), and the transmitter (4) is connected to the low-voltage feeder (3) through a splitter and a high-voltage disconnector. The multiple ground grids (5) are laid out with the multiple antenna units (1) as the center. The ground grids (5) are composed of multiple radially laid local ground grids. The multiple ground grids (5) are connected by metal ground grid wires or remain independent and unconnected.

2. The multi-element very low frequency transmitting antenna system according to claim 1, characterized in that, The horizontal distance between the centers of the plurality of antenna elements (1) is no greater than one-tenth of the working wavelength, and the height of the plurality of antenna elements (1) is one-thirtieth of the working wavelength.

3. The multi-element very low frequency transmitting antenna system according to claim 2, characterized in that, The antenna unit (1) is a self-standing metal tower antenna with its bottom insulated from the ground.

4. The multi-element very low frequency transmitting antenna system according to claim 1, characterized in that, The grounding grid (5) uses copper conductors.

5. The multi-element very low frequency transmitting antenna system according to claim 1, characterized in that, The transmitter (4) room includes a branching device and multiple high-voltage disconnect switches, which are respectively connected to a low-voltage feeder (3).

6. A tuning method for a multi-element very low frequency transmitting antenna system as described in any one of claims 1 to 5, characterized in that, The method includes the following steps: The transmitter (4) excites the plurality of antenna elements (1) through the low-voltage feeder (3) and the tuning pavilion (2); The transmitter (4) achieves two power supply modes, namely full-feed tuning mode and multi-antenna multi-tuning mode, by controlling the on / off state of the high-voltage disconnect switch; In the fully fed tuning mode, the transmitter (4) excites all the antenna elements (1) in parallel through the low-voltage feed line (3). In the multi-antenna multi-tuning mode, the transmitter (4) excites only the group of antenna elements (1) connected to it through the low-voltage feeder (3), while the other antenna elements (1) are excited through spatial coupling.

7. The tuning method according to claim 6, characterized in that, include: The transmitter (4) excites all the antenna elements (1) in parallel through the low-voltage feed line (3) so that the input current of each antenna element (1) is equal.

8. The tuning method according to claim 6, characterized in that, include: In the multi-antenna multi-tuning mode, the transmitter (4) excites only the group of antenna elements (1) connected to it through the low-voltage feed line (3), while the other antenna elements (1) are excited through spatial coupling.

9. The tuning method according to claim 6, characterized in that, include: The transmitter (4) distributes power reasonably to each antenna unit (1) through the splitter device, ensuring that each antenna unit (1) receives appropriate excitation power, thereby improving the transmission effect of the entire antenna system.

10. The tuning method according to claim 6, characterized in that, The transmitter (4) switches between different working modes by controlling the on / off state of the high-voltage disconnect switch to adapt to different transmission needs and environmental conditions.

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