Antenna radiation unit

Abstract

The present invention discloses an antenna radiating unit, comprising two pairs of orthogonally polarized dipole radiating units, a plurality of feed baluns connected to the dipole radiating units, and a plurality of coaxial cables. The dipole radiating unit comprises two dipole arms, from which an extension portion extends downward, forming a closed loop structure with the dipole arms. One end of the dipole arm is connected to the feed balun, and the other end is provided with a coupling structure on the end of an adjacent dipole arm. By improving the dipole arm structure, the present invention improves the broadband characteristics and impedance matching characteristics of the radiating unit, thereby expanding its application.

Description

Technical Field

[0001] The present invention relates to the field of base station antennas, and in particular to an antenna radiation unit with adjustable operating frequency band. Background Art

[0002] The prior art related to the present invention can refer to an antenna radiating unit and its feeding method disclosed in Chinese invention patent publication number CN103337712B. The antenna radiating unit includes two pairs of dipole radiating units with orthogonal polarizations, each of which is mounted on a metal reflector via a balun. Each balun includes two parallel and adjacent support columns, and each dipole radiating unit includes two unit arms symmetrically fixed to the two support columns. The triangular ring suspended from the dipole arm in this solution extends from the end of the dipole arm, and no coupling structure is provided between adjacent dipole arms. The dipole arm strength of this structure is weak, the electrical performance is poor, and the operating frequency of the dipole cannot be changed, making its application less flexible. Summary of the Invention

[0003] The purpose of the present invention is to overcome the defects of the prior art and provide an antenna radiation unit that adopts multiple coupling structures to effectively broaden the operating frequency band of the base station antenna and make it widely applicable.

[0004] To achieve the above-mentioned objectives, the present invention proposes the following technical solution: an antenna radiating unit, which includes two pairs of dipole radiating units with orthogonal polarizations, a plurality of feeding baluns connected to the dipole radiating units, and a plurality of coaxial cables, wherein the dipole radiating unit includes two dipole arms, the two ends of the dipole arm are respectively a first coupling end and a second coupling end, the two first coupling ends of each dipole radiating unit are adjacent, and the first coupling end is connected to a feeding balun, extending downward from the dipole arm to form an extension portion, the extension portion and the dipole arm form a closed ring structure, and the two adjacent second coupling ends are provided with a first coupling structure.

[0005] Preferably, the vibrator arm includes a main body portion and a coupling portion, wherein the main body portion is formed by extending downward from one side of the coupling portion and is arranged at an obtuse angle to the coupling portion.

[0006] Preferably, at least one step is formed at the bottom of the main body.

[0007] Preferably, the closed ring structure formed by the extension portion and the vibrator arm is a rectangular ring.

[0008] Preferably, the first coupling structure includes an isolation member spanning two adjacent second coupling ends and a first coupling member, and the isolation member is located between the first coupling member and the dipole arm.

[0009] Preferably, the isolation member is made of insulating material, and the first coupling member is made of metal material.

[0010] Preferably, each of the dipole radiating units corresponds to a coaxial cable and two feeding baluns, and the coaxial cable is fixed on one feeding balun and electrically connected to the other feeding balun.

[0011] Preferably, a second coupling structure is provided on two adjacent feeding baluns connected to each of the dipole radiating elements.

[0012] Preferably, the second coupling structure includes a second coupling member installed at two adjacent first coupling ends.

[0013] Preferably, the second coupling structure further includes a third coupling member mounted on two adjacent feeding baluns.

[0014] Preferably, the second coupling member includes a first limiting protrusion, two first coupling parts and two fixed parts, the first limiting protrusion is clamped between the two feeding baluns; the two end surfaces of the first limiting protrusion extend outward to form the two first coupling parts, and the first coupling parts are attached to the feeding balun surface on the corresponding side; the top ends of the two first coupling parts are respectively bent outward to extend to form the two fixed parts, and the two fixed parts are respectively fixed on the vibrator arms on the corresponding sides.

[0015] Preferably, the third coupling member includes a second limiting protrusion and two second coupling parts, the second limiting protrusion is clamped between the two feeding baluns, and the two end surfaces of the second limiting protrusion extend outward to form the two second coupling parts, and each second coupling part is fixed on the feeding balun surface on the corresponding side.

[0016] The beneficial effects of the present invention are:

[0017] 1. The setting position of the rectangular ring on the vibrator arm widens the coupling gap between the vibrator arms and is combined with the coupling structure set between the vibrator arms. By changing the length, thickness, relative dielectric constant and other characteristics of the coupling structure, the working frequency band of the vibrator can be adjusted, so that it can be applied to both the broadband 690-960KHZ working frequency band and the narrow frequency band therein, which is more flexible in application.

[0018] 2. The coupling structure set between the dipole arms and the feeding balun enhances the dipole strength and ensures the coupling gap distance between the dipole arms and the feeding balun. The coupling gap distance between the feeding baluns is beneficial to the feeding of the coaxial cable on the one hand and the welding of the dipole unit on the other hand. In addition, by adjusting the size of the coupling gap between the dipole arms and the feeding balun, the standing wave and radiation pattern characteristics of the antenna can be adjusted.

[0019] 3. The rectangular gradient irregular structure of the dipole arm can obtain broadband characteristics, which is beneficial to the impedance matching of the radiating unit; and the rectangular ring structure can optimize the two indicators of the antenna's axial cross-polarization and front-to-back ratio. By adopting this structure, the antenna's axial cross-polarization can be improved by about 5 dB, and the front-to-back ratio can be improved by about 7 dB.

[0020] 4. The present invention uses four coaxial cables for power feeding, which is conducive to the assembly of the antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of a partial explosion structure of the present invention;

[0022] Figure 2 It is a schematic diagram of the assembled structure of the present invention;

[0023] Figure 3 It is a side structural schematic diagram of the present invention;

[0024] Figure 4 It is a schematic diagram of the top structure of the present invention;

[0025] Figure 5 It is a bottom view structural diagram of the present invention;

[0026] Figure 6 is a schematic structural diagram of the second coupling member of the present invention;

[0027] Figure 7 It is a structural schematic diagram of the third coupling member of the present invention.

[0028] Reference numerals:

[0029] 1. Feed balun, 2. Coaxial cable, 3. Diode arm, 31. Main body, 32. Coupling part, 33. First coupling end, 34. Second coupling end, 4. Second coupling gap, 5. First coupling gap, 6. Extension part, 7. Isolation piece, 8. First coupling piece, 9. Second coupling piece, 91. First limiting protrusion, 92. First coupling part, 93. Fixing part, 10. Third coupling piece, 101. Second limiting protrusion, 102. Second coupling part, 11. Coaxial cable pad, 12. Limiting piece. DETAILED DESCRIPTION

[0030] The technical solutions of the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention.

[0031] The present invention discloses an antenna radiation unit, which improves the broadband characteristics and impedance matching characteristics of the radiation unit by improving the structure of the dipole arm.

[0032] Combine Figures 1 to 5As shown, an antenna radiating element disclosed in an embodiment of the present invention includes two pairs of dipole radiating elements with orthogonal polarizations (i.e., four dipole radiating elements), multiple feed baluns 1, multiple coaxial cables 2, a first coupling structure, and a second coupling structure. The dipole radiating elements are mounted on a reflector (not shown) via the feed baluns 1. Each dipole radiating element corresponds to one coaxial cable 2 and two feed baluns 1. The coaxial cable 2 is secured to one feed balun 1 and electrically connected to the other feed balun 1 by soldering, forming a mobile communication base station antenna.

[0033] Each dipole radiating unit includes two dipole arms 3. In this embodiment, the two dipole arms 3 of each dipole radiating unit are perpendicular to each other, that is, the angle between them is 90 degrees. In this way, the eight dipole arms 3 are combined to form a rectangular structure.

[0034] Each dipole arm 3 has a first coupling end 33 and a second coupling end 34, respectively, at either end. The two first coupling ends 33 of each dipole radiating element are adjacent, and the first coupling end 33 is connected to a feed balun 1. Because the first coupling ends 33 of the two dipole arms 3 are adjacent, the two feed baluns 1 connected thereto are also adjacent, and a second coupling gap 4 exists between the two feed baluns 1. The second coupling structure is mounted above this second coupling gap 4. A first coupling gap 5 exists between the second coupling end 34 of a dipole arm 3 and the second coupling end 34 of an adjacent dipole arm. The first coupling structure is mounted above this first coupling gap 5.

[0035] Each dipole arm includes a main body 31 and a coupling portion 32. In this embodiment, the coupling portion 32 is arranged horizontally and is a slender metal sheet structure; the main body 31 is formed by extending downward from one side of the coupling portion 32, and the angle between it and the coupling portion 32 is an obtuse angle. In this embodiment, the main body 31 is an irregular shape with a rectangular gradient, that is, a rectangular gradient structure with at least one step formed at the bottom. This structure can obtain broadband characteristics and is beneficial to the impedance matching of the radiating unit.

[0036] In this embodiment, an extension portion 6 is formed by extending downward from a middle position of the coupling portion 32, but not limited to the middle position. The extension portion 6 and the coupling portion 32 form a closed ring structure. That is, the extension portion 6 is located between the first coupling end 33 and the second coupling end 34 of the vibrator arm 3. Compared with the existing structure in which the extension portion 6 extends downward directly from both ends of the coupling portion 32, the extension portion structure of the present invention, which extends downward from the middle of the coupling portion 32, widens the coupling gap distance between the vibrator arms 3. Combined with the first coupling structure, the operating frequency band of the vibrator can be adjusted, making its application range more flexible.

[0037] The closed ring structure formed by the extension portion 6 and the coupling portion 32 is preferably a rectangular ring, but may also be other shapes such as a triangular ring. In this embodiment, 8 rectangular rings are included. The function of this ring structure is mainly to optimize the two indicators of the antenna's axial cross-polarization and front-to-back ratio. By adopting this structure, the antenna's axial cross-polarization can be improved by about 5 dB, and the front-to-back ratio can be improved by about 7 dB.

[0038] The first coupling structure connects the second coupling ends 34 of two adjacent dipole arms, which constitutes a coupling structure between the dipole arms, so that the dipole unit of the present invention can obtain a wider operating frequency band. Figure 1 As shown, in this embodiment, the first coupling structure specifically includes an isolator 7 and a first coupling member 8. The isolator 7 spans two adjacent second coupling ends 34, i.e., one end is fixed to one second coupling end 34, and the other end is fixed to another second coupling end 34 adjacent to the first second coupling end. Fixing holes for screws to pass through are provided in the isolator 7 and the vibrator arm, and the isolator 7 is fixed to the vibrator arm using screws or other means. The isolator 7 is located between the vibrator arm and the first coupling member 8. The isolator 7 is a plastic member. On the one hand, it increases the strength of the vibrator and ensures the coupling gap distance between the vibrator arms; on the other hand, it also serves to isolate the metal (first coupling member) from the metal (vibrator arm) and to adjust the standing wave.

[0039] The first coupling member 8 is stacked on the isolation member 7, with its two ends respectively spanning two adjacent second coupling ends 34. Both ends are provided with fixing holes, concentrically located with the isolation member 7 and the second coupling end 34, for screws to penetrate. Screws are sequentially inserted through the through-holes of the first coupling member 8 and the isolation member 7 to secure the first coupling member 8 and the isolation member 7 to the dipole arms 3. In this embodiment, the first coupling member 8 is a sheet metal. Structurally, it increases the strength of the dipole and ensures the coupling gap distance between the dipole arms 3. Electrically, it, together with the isolation member 7, constitutes the coupling structure between the dipole arms 3. By adjusting parameters such as the thickness, relative dielectric constant, and size of the isolation member 7, as well as the length, width, and size of the first coupling member 8, the operating frequency band of the dipole can be adjusted. This allows the dipole to operate in both the broadband 690-960 kHz operating frequency band and the narrower frequency band within it, providing greater flexibility in application.

[0040] The second coupling structure connects two adjacent feed baluns 1, forming a coupling structure between the feed baluns 1. In this embodiment, the second coupling structure includes a second coupling member 9 and a third coupling member 10. The second coupling member 9 is installed at the top position (i.e., the first coupling end 33 of the dipole arm 3) between the two adjacent feed baluns 1 connected to the dipole radiating element, and connects the two dipole arms 3. The third coupling member 10 is installed at the middle position between the two adjacent feed baluns 1 connected to the dipole radiating element, and connects the two feed baluns 1. The coupling scheme using the second coupling structure not only increases the strength of the dipole element while preventing damage to the coaxial cable 2 caused by antenna vibration, but also facilitates the welding of the dipole element. The standing wave and directional pattern characteristics of the antenna can be adjusted by adjusting the size of the second coupling gap.

[0041] Specifically, combined Figure 1 and Figure 6 As shown, the second coupling member 9 includes a first limiting protrusion 91, two first coupling portions 92, and two fixing portions 93. The first limiting protrusion 91 is positioned between the two feed baluns 1. The two end surfaces of the first limiting protrusion 91 extend outward to form the two first coupling portions 92. The first coupling portion 92 adheres to the surface of the feed balun 1 and, together with the first limiting protrusion 91, forms a slot that mates with the end surface of the feed balun 1. The second coupling member 9 is secured to the corresponding feed balun 1 through this slot. The top ends of the two first coupling portions 92 bend outward and extend to form the two fixing portions 93. The two fixing portions 93 are respectively fixed to the first coupling portions 92 of the corresponding dipole arms 3 via a screw and perforation structure. The second coupling member 9 increases dipole strength and ensures a coupling gap between the feed baluns 1, thereby adjusting the dipole standing wave.

[0042] Combine Figure 1 and Figure 7 As shown, the third coupling member 10 includes a second stopper protrusion 101 and two second coupling portions 102. The two end surfaces of the second stopper protrusion 101 extend outward to form the two second coupling portions 102. The second stopper protrusion 101 is positioned between the two feed baluns 1. The second coupling portion 102 is attached to the surface of the feed balun 1 and forms a slot with the corresponding second stopper protrusion 101 to mate with the end surface of the feed balun. The third coupling member 10 is secured to the corresponding feed balun 1 through this slot. The second coupling portion 102 is also secured to the corresponding feed balun 1 via a screw and perforation structure. The third coupling member 10 also increases the strength of the oscillator, preventing damage to the coaxial line caused by antenna vibration, and ensuring a sufficient coupling gap between the baluns. In this embodiment, both the second coupling member 9 and the third coupling member 10 are plastic.

[0043] As an alternative embodiment, only one of the second coupling member 9 and the third coupling member 10 in the above-mentioned second coupling structure can be provided. If only the second coupling member 9 is provided, the oscillator strength can also be enhanced to ensure the effect of the coupling gap between the feeding baluns 1, but the enhancement of the oscillator strength is slightly weaker.

[0044] Each dipole radiating element is connected to two feed baluns 1. A coaxial cable pad 11 is located at the top of one feed balun, extending toward the other feed balun. This coaxial cable pad 11 is positioned below the first retaining protrusion 91 of the second coupling element. A coaxial cable 2 is positioned along one side of the other feed balun 1, secured in place by multiple retaining members 12 formed thereon. Its inner conductor is soldered to the coaxial cable pad 11. Thus, the radiating element of the present invention incorporates four coaxial cables 2, facilitating antenna assembly.

[0045] In addition, since the coaxial cable pad 11 is located below the first limiting protrusion 91 of the second coupling member, the first limiting protrusion 91 also plays a role in ensuring the gap between the coaxial cable pad 11 and the feeding balun 1.

[0046] The present invention adopts a sheet metal structure as a whole, is easy to produce and can reduce the overall weight of the antenna.

[0047] The technical content and technical features of the present invention have been disclosed as above. However, those skilled in the art may still make various substitutions and modifications based on the teachings and disclosures of the present invention without departing from the spirit of the present invention. Therefore, the scope of protection of the present invention should not be limited to the contents disclosed in the embodiments, but should include various substitutions and modifications that do not depart from the present invention and are covered by the claims of this patent application.

Claims

1. An antenna radiating unit, comprising two pairs of dipole radiating units with orthogonal polarizations, a plurality of feed baluns connected to the dipole radiating units, and a plurality of coaxial cables, wherein each dipole radiating unit comprises two dipole arms, each dipole arm comprises a main body and a coupling portion, the main body is an irregular shape with a rectangular gradient, and its two ends are respectively a first coupling end and a second coupling end, the two first coupling ends of each dipole radiating unit are adjacent, and the first coupling end is connected to a feed balun, characterized in that: The main body is formed by extending downward from one side of the coupling portion and is arranged at an obtuse angle to the coupling portion. An extension portion is extended downward from the middle position of the dipole arm coupling portion. The extension portion and the dipole arm form a closed ring structure. The two adjacent second coupling ends are provided with a first coupling structure, and the two adjacent feed baluns are provided with a second coupling structure connecting the two feed baluns. The second coupling structure includes a second coupling member, and the second coupling member includes a first limiting protrusion, two first coupling portions and two fixing portions.

2. The antenna radiation unit according to claim 1, characterized in that: At least one step is formed at the bottom of the main body.

3. The antenna radiation unit according to claim 1, wherein: The closed ring structure formed by the extension portion and the vibrator arm is a rectangular ring.

4. The antenna radiation unit according to claim 1, wherein: The first coupling structure includes an isolation member spanning two adjacent second coupling ends and a first coupling member, wherein the isolation member is located between the first coupling member and the dipole arm.

5. The antenna radiation unit according to claim 4, characterized in that: The isolation member is made of insulating material, and the first coupling member is made of metal material.

6. The antenna radiation unit according to claim 1, characterized in that: Each of the dipole radiation units corresponds to a coaxial cable and two feeding baluns. The coaxial cable is fixed on one feeding balun and electrically connected to the other feeding balun.

7. The antenna radiation unit according to claim 1, characterized in that: The second coupling member is installed on two adjacent first coupling ends.

8. The antenna radiation unit according to claim 1, wherein: The second coupling structure includes a third coupling member, and the third coupling member is installed at a middle position of two adjacent feeding baluns.

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