L-band omnidirectional high-gain array antenna based on decoupling technology

Abstract

The invention discloses an L-band omnidirectional high-gain array antenna based on a decoupling technology. The L-band omnidirectional high-gain array antenna comprises a plurality of main radiation units, a plurality of auxiliary radiation units, a central metal tube and a feed network, the plurality of main radiation units are sequentially arranged from top to bottom along the central metal tube, and each main radiation unit is of an inverted dipole structure and comprises an upper vibrator and a lower vibrator; the lower part of each lower oscillator is connected with an auxiliary radiation unit; the upper end of the central metal tube is connected with the upper end of the upper oscillator of the main radiation unit at the topmost end, passes through the centers of each main radiation unit and each auxiliary radiation unit, and is connected with each main radiation unit and each auxiliary radiation unit; the lower end of the central metal tube is connected with the feed network; and a feeder line in the feed network is electrically connected with each main radiation unit in the central metal tube. According to the invention, the antenna gain is improved, the impedance matching is optimized, the antenna structure is simplified, and the traditional shunt-fed array antenna is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of antenna communication equipment, and in particular to an L-band omnidirectional high-gain array antenna based on a decoupling technology. Background Art

[0002] With the continuous development of communication technology, people have higher and higher requirements for the working bandwidth, communication distance and transmission rate of communication stations, and the supporting antennas are also developing in the direction of wide bandwidth and high gain. Compared with a single radiating element, array antennas can more effectively process multi-band signals and support a wider spectrum range. In addition, the gain of array antennas can be improved by increasing the number of elements in the array and optimizing the arrangement to meet the high gain requirements.

[0003] According to the different feeding methods, omnidirectional array antennas can be divided into series-fed arrays and parallel-fed arrays. Serial-fed omnidirectional array antennas can meet high gain requirements, but the working bandwidth is narrow, usually not exceeding 20% ​​of the relative bandwidth, and it becomes narrower as the number of array elements increases, making it difficult to meet broadband working requirements. Although parallel-fed omnidirectional array antennas can meet broadband requirements, since each array element has a feed line, as the number of array elements increases, the number of feed lines also increases, and the coupling between the feed line and the radiator becomes stronger. On the one hand, the strong coupling between the feed line and the radiator will cause the input impedance of the radiator to be distorted, mismatched with the feed line impedance, and the voltage standing wave ratio to deteriorate; on the other hand, it will cause strong induced currents on the surface of the feed line, so the feed line generates spurious radiation, which is superimposed on the radiation of the radiator, causing the antenna radiation pattern to be distorted and the gain to be reduced.

[0004] Therefore, the present invention proposes an L-band omnidirectional high-gain array antenna based on decoupling technology, which is used in conjunction with a radio station in the same frequency band to optimize the problems existing in the traditional parallel-fed array, improve the antenna gain, optimize the impedance matching, and simplify the antenna structure. Summary of the invention

[0005] In view of this, the present invention provides an L-band omnidirectional high-gain array antenna based on decoupling technology to solve the technical problems of worsening antenna voltage standing wave ratio and reduced gain caused by coupling between the feed line and the radiator of the traditional parallel-fed array antenna.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0007] The present invention provides an L-band omnidirectional high-gain array antenna based on decoupling technology, comprising a plurality of main radiating units, a plurality of auxiliary radiating units, a central metal tube and a feeding network;

[0008] A plurality of main radiation units are arranged in sequence from top to bottom along the central metal tube, each main radiation unit is an inverted dipole structure, including an upper oscillator and a lower oscillator; an auxiliary radiation unit is connected below each lower oscillator, and the number of the auxiliary radiation units is the same as that of the main radiation units;

[0009] The upper end of the central metal tube is connected to the upper end of the upper oscillator of the topmost main radiating unit, passes through the center of each main radiating unit and the auxiliary radiating unit, and is electrically connected to each main radiating unit and the auxiliary radiating unit; the lower end of the central metal tube is connected to the feeding network; the feeder in the feeding network is electrically connected to each main radiating unit inside the central metal tube.

[0010] In a preferred implementation, the feed network includes a radio frequency connector, a main feed line, a power divider, and a branch feed line having the same number as the main radiating units, which are connected in sequence from bottom to top;

[0011] The power divider is arranged at the bottom of the central metal tube, and is connected to the lower end of the auxiliary radiation unit located at the bottom through an insulating connector; the upper end of the power divider is electrically connected to each branch feeder line, and the lower end is electrically connected to the main feeder line;

[0012] Each branch feeder line penetrates from the bottom of the central metal tube and is electrically connected to each main radiating unit.

[0013] In a preferred implementation, every two adjacent main radiation units and every two adjacent auxiliary radiation units are arranged at an equidistant distance.

[0014] In a preferred implementation, both the upper oscillator and the lower oscillator are made of a first metal tube with a length of one quarter of the working wavelength of the antenna; the first metal tube is open at the lower end and electrically connected to the central metal tube at the upper end.

[0015] In a preferred implementation, each auxiliary radiation unit is made of a second metal tube; the second metal tube has an opening at the lower end and an upper end electrically connected to the central metal tube.

[0016] In a preferred implementation, the central metal tube has a long hole between each pair of upper and lower vibrators;

[0017] Each branch feeder line penetrates from the bottom of the central metal tube, and passes through the long holes in turn and is connected to the corresponding main radiation unit.

[0018] In a preferred implementation, the feeder line includes an outer conductor and an inner conductor, the outer conductor is electrically connected to the lower dipole, and the inner conductor is electrically connected to the upper dipole.

[0019] In a preferred implementation, the antenna also includes an antenna cover, and the bottom end of the antenna cover is connected to the bottom of the radio frequency network; the multiple main radiating units, the multiple auxiliary radiating units, the central metal tube and the feeding network are all located inside the antenna cover.

[0020] In a preferred implementation, the bottom end of the antenna cover is connected to the bottom of the radio frequency connector.

[0021] In a preferred implementation manner, the number of the main radiation units and the number of the auxiliary radiation units are both four, and the power divider is a one-to-four power divider.

[0022] Compared with the prior art, the L-band omnidirectional high-gain array antenna based on decoupling technology provided by the present invention has the following advantages:

[0023] (1) By hiding the feeder of the feeding network in the central metal tube, the coupling between the feeder and the main radiating unit is converted into the coupling between the central metal tube and the main radiating unit. The antenna performance is no longer affected by the feeder status and the performance is more stable.

[0024] (2) By inverting the upper oscillator of the dipole, the upper oscillator and the central metal tube are short-circuited to form a λ / 4 short-circuit line. The transmission impedance between the two at the feeding point of the main radiating unit is infinite, which greatly reduces the coupling between the two. Compared with the traditional parallel-fed array antenna, the port standing wave is better and the omnidirectional gain is higher.

[0025] (3) An auxiliary radiating unit is added below the main radiating unit to direct the residual skin current on the central metal tube to the surface of the auxiliary radiating unit, forming secondary radiation, which is superimposed in phase with the radiation of the main radiating unit to further improve the antenna gain.

[0026] (4) Both the main radiation unit and the auxiliary radiation unit are fixed on the central metal tube, without the need for additional insulating connectors, making installation more convenient and simple.

[0027] In summary, the antenna designed by the present invention effectively reduces the coupling between the main radiating unit and the feeder, improves impedance matching, and increases gain; the main radiating unit and the auxiliary radiating unit optimize the radiation effect by superimposing in phase; the main radiating unit and the auxiliary radiating unit are fixed on the central metal tube, and no additional insulating parts are required, which simplifies the installation process. The present invention has significant advantages in gain improvement, impedance matching optimization, and structural simplification. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of the structure of an L-band omnidirectional high-gain array antenna based on a decoupling technology provided by an embodiment of the present invention;

[0029] Figure 2 A schematic diagram of the structure of a power divider provided in an embodiment of the present invention;

[0030] Figure 3 A schematic diagram of the structure of the connection between the feeder line and the main radiation unit provided in an embodiment of the present invention;

[0031] Figure 4 The antenna provided in the embodiment of the present invention is L ~f H Schematic diagram of measured curve of voltage standing wave ratio within the frequency band;

[0032] Figure 5 The antenna provided in the embodiment of the present invention is L ~f H Schematic diagram of measured gain curve within the frequency band;

[0033] Figure 6 The antenna provided in the embodiment of the present invention is L ~f H Schematic diagram of the voltage standing wave ratio comparison between the conventional parallel-fed four-element array antenna within the frequency band;

[0034] Figure 7 The antenna provided in the embodiment of the present invention is L ~f H Schematic diagram of gain comparison with traditional parallel-fed four-element array antenna within the frequency band;

[0035] Among them, 1-RF connector, 2-main feeder, 3-power divider, 4-sub-feeder, 5-insulating connector, 6-auxiliary radiation unit, 7-lower oscillator of main radiation unit, 8-upper oscillator of main radiation unit, 9-central metal tube, 10-radome. DETAILED DESCRIPTION

[0036] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0037] This embodiment takes the number of the main radiation unit and the auxiliary radiation unit as four as an example to describe in detail the L-band omnidirectional high-gain array antenna based on the decoupling technology provided by the present invention.

[0038] See also Figure 1 , the L-band omnidirectional high-gain array antenna based on decoupling technology provided in this embodiment includes: four main radiating units, four auxiliary radiating units 6, a central metal tube 9 and a feeding network;

[0039] A plurality of main radiation units are arranged in sequence from top to bottom along the central metal tube, and each main radiation unit is an inverted dipole structure, including an upper oscillator 8 and a lower oscillator 7; an auxiliary radiation unit 6 is connected below each lower oscillator 7;

[0040] The upper end of the central metal tube 9 is connected to the lower oscillator 7 of the main radiating unit arranged at the topmost point, passes through the center of each main radiating unit and the auxiliary radiating unit 6, and is electrically connected to each main radiating unit and the auxiliary radiating unit 6; the lower end of the central metal tube 9 is connected to the feeding network; the feeder in the feeding network is electrically connected to each main radiating unit inside the central metal tube.

[0041] In the antenna design of the present invention, the feeder of the radiating unit is hidden inside the central metal tube, and the central metal tube shields the feeder, converting the coupling between the feeder and the radiating unit into the coupling between the central metal tube and the radiating unit. Increasing the number of feeders or making the feeders thicker will no longer lead to greater coupling, and the antenna performance is no longer affected by the feeder status, and the performance is more stable.

[0042] As a preferred embodiment, Figure 1 As shown, the feeding network includes a radio frequency connector 1, a main feeder 2, a power divider 3 and four branch feeders 4 connected in sequence from bottom to top;

[0043] The power divider 3 is arranged at the bottom of the central metal tube 9 and connected to the lower end of the auxiliary radiation unit 6 at the bottom through the insulating connector 5; the power divider is arranged at the bottom of the central metal tube and connected to the auxiliary radiation unit through the insulating connector, which effectively avoids electrical short circuit and signal interference and ensures the stability and reliability of the feed network. At the same time, the feed network is integrated into the central metal tube, which reduces the use of external connectors, simplifies the installation steps, and reduces the difficulty and cost of maintenance.

[0044] The upper end of the power divider 3 is electrically connected to each branch feeder line 4, and the lower end is electrically connected to the main feeder line 2; the schematic diagram of the power divider structure is shown in Figure 2 The signal of the main feeder is evenly distributed to four branch feeders through a power divider. The four branch feeders are kept of equal length to ensure that each main radiating unit can obtain power input of equal amplitude and phase, thus improving the overall radiation efficiency of the antenna.

[0045] Each branch feeder 4 penetrates from the bottom of the central metal tube 9 and is electrically connected to each main radiating unit. The branch feeder penetrates from the bottom of the central metal tube and is connected to the main radiating unit, making full use of the space of the central metal tube, making the entire antenna structure more compact and reducing the complexity of external wiring.

[0046] As a preferred embodiment, Figure 1 As shown, the antenna also includes an antenna cover 10, the bottom end of which is connected to the bottom of the radio frequency network; the multiple main radiating units, the multiple auxiliary radiating units 6, the central metal tube 9 and the feeding network are all located inside the antenna cover 10.

[0047] Specifically, the bottom end of the antenna cover 10 is connected to the bottom of the RF connector 1 .

[0048] The radome has good electromagnetic permeability and can ensure efficient signal transmission. Under the protection of the radome, the antenna system can be effectively protected from the influence of the external environment, such as rain, snow, wind, sand and dust, thereby extending the service life of the antenna. The connection method between the bottom of the radome and the RF connector can ensure the stable transmission of the RF signal, thereby improving the overall performance of the system.

[0049] As a preferred embodiment, every two adjacent main radiation units and every two adjacent auxiliary radiation units 6 are arranged at an equidistant distance.

[0050] The equidistant arrangement setting can first make the electromagnetic coupling between the main radiating unit and the auxiliary radiating unit more uniform, so as to better realize the in-phase superposition of the secondary radiation and the main radiation, which helps to optimize the feeding network design of the antenna, reduce the feeding loss, and improve the radiation efficiency of the antenna; secondly, the equidistantly arranged radiating units can better control the electromagnetic coupling between the units and reduce the mutual interference between the units; finally, the equidistant arrangement makes the structure of the antenna more regular and symmetrical, simplifies the layout design of the antenna, reduces errors in the manufacturing process, and facilitates design and manufacturing.

[0051] Therefore, the design of equidistant arrangement not only optimizes the radiation pattern, but also increases the gain, reduces coupling, and simplifies the structure, thereby comprehensively improving the overall performance of the antenna.

[0052] As a preferred embodiment, Figure 3 As shown, the feeder line 4 includes an outer conductor and an inner conductor, the outer conductor is electrically connected to the lower dipole 7 of the main radiation unit, and the inner conductor is electrically connected to the upper dipole 8 of the main radiation unit.

[0053] By connecting the inner and outer conductors separately, the electromagnetic coupling between the feeder and the radiating unit can be effectively reduced, the signal can be prevented from being interfered with during the feeding process, and the performance stability of the antenna can be improved, so as to better control the impedance matching between the feeding network and the radiating unit, reduce reflection loss, and improve the radiation efficiency of the antenna. Through precise electrical connection, it can be ensured that each main radiating unit can receive signals evenly and radiate efficiently, further improving the overall gain of the antenna and the consistency of the radiation pattern.

[0054] As a preferred embodiment, the central metal tube 9 has a long hole between each pair of upper oscillators 8 and lower oscillators 7; each branch feed line 4 passes through the bottom of the central metal tube 9, and passes through the long hole in turn to be connected to each main radiation unit.

[0055] The long hole provides a clear channel for the feeder line, avoiding the messy arrangement of the feeder line inside the central metal tube, making the entire antenna structure more compact and orderly, and reducing space occupation. The feeder line is directly connected to the main radiation unit through the long hole, avoiding multiple bends and unnecessary length increase of the feeder line inside the metal tube, thereby reducing signal transmission loss.

[0056] In some embodiments, part of the feeder line 4 is coiled inside the insulating connector 5 .

[0057] The design of coiling part of the sub-feeder line inside the insulating connector can effectively utilize the internal space of the insulating connector, reduce the space occupied by the sub-feeder line, and make the antenna structure more compact; under the protection of the insulating connector, the sub-feeder line is prevented from being affected by environmental factors such as moisture and dust, thereby extending the service life of the antenna; at the same time, it can also reduce the mechanical stress of the sub-feeder line and avoid signal loss caused by vibration or external force.

[0058] As a preferred embodiment, the upper oscillator 8 and the lower oscillator 7 are both made of a first metal tube with a length of one quarter of the working wavelength of the antenna; the first metal tube is open at the lower end and electrically connected to the central metal tube 9 at the upper end.

[0059] By inverting the upper oscillator of the dipole, the upper oscillator 8 and the central metal tube 9 are short-circuited to form a λ / 4 short-circuit line. The transmission impedance between the two at the feeding point of the main radiating unit is infinite, which greatly reduces the coupling between the two. Compared with the traditional parallel-fed array antenna, the port matching is better and the omnidirectional gain is higher. The λ / 4 length oscillator has good resonance characteristics at the operating frequency, which can ensure that the antenna maintains stable performance throughout the entire operating frequency band. The upper and lower oscillators use independent metal tube structures, which reduces the electromagnetic coupling between the oscillators and avoids mutual interference of signals between the oscillators.

[0060] The first metal tube is made of a material with high conductivity to reduce transmission loss and improve radiation efficiency. The inner and outer surfaces of the metal tube should be smooth and clean, without defects such as pinholes, cracks, peeling, and slag inclusions.

[0061] As a preferred embodiment, each auxiliary radiation unit is made of a second metal tube; the second metal tube has an opening at the lower end and an upper end electrically connected to the central metal tube.

[0062] The second metal tube is made of copper or silver-plated aluminum with high conductivity, and the upper end needs to be reliably electrically connected to the central metal tube to ensure the stability of signal transmission. In addition, the second metal tube should have sufficient mechanical strength to adapt to different installation environments and conditions.

[0063] For a demonstration of the actual performance of the antenna, see Figure 4 , Figure 4 The antenna of this embodiment is at fL ~f H The voltage standing wave ratio test result diagram of the frequency band, where the horizontal axis is the frequency and the vertical axis is the voltage standing wave ratio. Figure 4 It can be seen from the figure that the antenna of this embodiment has a L ~f H The standing wave ratio is below 2 in the entire frequency band, and the relative bandwidth is about 38%, which can meet the communication equipment's requirements for wide-bandwidth antennas.

[0064] See also Figure 5 , Figure 5 The antenna of this embodiment is at f L ~f H The gain test result of the frequency band is shown in the figure, where the horizontal axis is the frequency and the vertical axis is the gain. Figure 5 It can be seen from the figure that the antenna of this embodiment has a L ~f H The gain in the entire frequency band is above 7.8dBi, which can meet the high gain requirements of communication equipment for antennas.

[0065] See also Figure 6 , Figure 6 The antenna of this embodiment is at f L ~f H A comparison chart of the voltage standing wave ratio test in the frequency band with the traditional parallel-fed four-element array antenna, wherein the horizontal axis is the frequency and the vertical axis is the voltage standing wave ratio. It can be seen from the figure that the overall voltage standing wave ratio of the antenna in this embodiment is lower, while the standing wave ratio of the traditional parallel-fed four-element array antenna is worse the lower the frequency.

[0066] See also Figure 7 , Figure 7 The antenna of this embodiment is at f L ~f H A comparison chart of the gain test in the frequency band with the traditional parallel-fed four-element array antenna, where the horizontal axis is frequency and the vertical axis is gain. It can be seen from the figure that the antenna of this embodiment has a higher gain than the traditional parallel-fed four-element array in the whole frequency band, and the gain is increased by about 1dB on average. At the same time, the gain fluctuation is also significantly reduced.

[0067] The L-band omnidirectional high-gain array antenna based on the decoupling technology provided in this embodiment hides the feeder of the radiating unit inside the central metal tube, and the central metal tube shields the feeder, thereby converting the coupling between the feeder and the radiating unit into the coupling between the central metal tube and the radiating unit. Increasing the number of feeders or thickening the feeders will no longer lead to greater coupling, and the antenna performance is no longer affected by the feeder status, and the performance is more stable.

[0068] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. An L-band omnidirectional high-gain array antenna based on decoupling technology, characterized in that: It includes a plurality of main radiating units, a plurality of auxiliary radiating units, a central metal tube and a feeding network; A plurality of main radiation units are arranged in sequence from top to bottom along the central metal tube, each main radiation unit is an inverted dipole structure, including an upper oscillator and a lower oscillator; an auxiliary radiation unit is connected below each lower oscillator, and the number of the auxiliary radiation units is the same as that of the main radiation units; The upper end of the central metal tube is connected to the upper end of the upper oscillator of the topmost main radiating unit, passes through the center of each main radiating unit and the auxiliary radiating unit, and is electrically connected to each main radiating unit and the auxiliary radiating unit; the lower end of the central metal tube is connected to the feeding network; the feeder in the feeding network is electrically connected to each main radiating unit inside the central metal tube.

2. The L-band omnidirectional high-gain array antenna based on decoupling technology according to claim 1, characterized in that: The feeding network includes a radio frequency connector, a main feeder, a power divider, and a number of branch feeders that is the same as the number of main radiating units, which are connected in sequence from bottom to top; The power divider is arranged at the bottom of the central metal tube, and is connected to the lower end of the auxiliary radiation unit located at the bottom through an insulating connector; the upper end of the power divider is electrically connected to each branch feeder line, and the lower end is electrically connected to the main feeder line; Each branch feeder line penetrates from the bottom of the central metal tube and is electrically connected to each main radiating element.

3. The L-band omnidirectional high-gain array antenna based on decoupling technology according to claim 1, characterized in that: Every two adjacent main radiation units and every two adjacent auxiliary radiation units are arranged at an equidistant distance.

4. The L-band omnidirectional high-gain array antenna based on decoupling technology according to claim 1, characterized in that: The upper oscillator and the lower oscillator are both made of a first metal tube with a length of one quarter of the working wavelength of the antenna; the lower end of the first metal tube is open, and the upper end is electrically connected to the central metal tube.

5. The L-band omnidirectional high-gain array antenna based on decoupling technology according to claim 1, characterized in that: Each auxiliary radiation unit is made of a second metal tube; the lower end of the second metal tube is open, and the upper end is electrically connected to the central metal tube.

6. The L-band omnidirectional high-gain array antenna based on decoupling technology according to claim 2, characterized in that: The central metal tube has a long hole between each pair of upper and lower vibrators; Each branch feeder line penetrates from the bottom of the central metal tube, and successively passes through the long holes and is connected to the corresponding main radiation unit.

7. The L-band omnidirectional high-gain array antenna based on decoupling technology according to claim 6, characterized in that: The feeder line comprises an outer conductor and an inner conductor, wherein the outer conductor is electrically connected to the lower oscillator, and the inner conductor is electrically connected to the upper oscillator.

8. The L-band omnidirectional high-gain array antenna based on decoupling technology according to claim 2, characterized in that: The antenna also includes an antenna cover, the bottom end of which is connected to the bottom of the radio frequency network; the multiple main radiation units, the multiple auxiliary radiation units, the central metal tube and the feeding network are all located inside the antenna cover.

9. The L-band omnidirectional high-gain array antenna based on decoupling technology according to claim 8, characterized in that: The bottom end of the antenna cover is connected to the bottom of the radio frequency connector.

10. The L-band omnidirectional high-gain array antenna based on decoupling technology according to claim 2, characterized in that: The number of the main radiation units and the number of the auxiliary radiation units are both four, and the power divider is a one-to-four power divider.

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