A low-frequency radiation unit and base station antenna

Abstract

Embodiments of the present invention are applicable to the field of filter technology and include a radiator, a feed structure, and an array baseplate. One end of the feed structure is connected to the radiator for feeding, and the other end is connected to the array baseplate. The radiator comprises two pairs of orthogonally distributed annular radiating arms, each comprising multiple segments. Adjacent segments are connected by a spatial decoupling structure. The spatial decoupling structure comprises a first strip and a second strip. One end of the first strip and one end of the second strip are respectively connected to two adjacent segments, and the other ends of the first strip and the second strip are mutually opposed and spaced apart. The present invention aims to achieve spatial decoupling and effectively address the high- and low-frequency mutual coupling problem in base station antennas.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless communications, and in particular relates to a low-frequency radiation unit and a base station antenna. Background Art

[0002] With the rapid development of the internet, wireless communications are moving towards multi-frequency, lightweight, and high-performance development. Antennas, as the passive components at the end of wireless mobile communications, have long been a hot topic in wireless communications research. Their performance directly impacts wireless communication performance. To adapt to the rapid development of wireless communication systems, miniaturization and multi-frequency co-location of wireless base station antennas have become common market demands.

[0003] The multi-frequency nature of wireless communication base station antennas requires the use of radiating elements with a wider range of frequencies. The miniaturization of wireless communication base stations also necessitates more compact placement of these elements. The close proximity of high- and low-frequency radiating elements increases mutual coupling and interference between them. The influence of low frequencies can severely distort the directivity and pattern of high-frequency radiating elements, degrading the base station's signal coverage, impacting the user experience of mobile devices, and even causing network outages. Summary of the Invention

[0004] The technical problem to be solved by the embodiments of the present invention is to provide a low-frequency radiation unit and a base station antenna, aiming to achieve a spatial decoupling function and effectively solve the high- and low-frequency mutual coupling problem in the base station antenna.

[0005] An embodiment of the present invention is implemented as follows: a low-frequency radiation unit includes a radiator, a feeding structure, and an array base plate, one end of the feeding structure is connected to the radiator for feeding, and the other end of the feeding structure is connected to the array base plate, the radiator includes two pairs of orthogonally distributed annular radiation arms, the annular radiation arms include multiple segments, and adjacent two segments are connected by a spatial decoupling structure, the spatial decoupling structure includes a first line strip and a second line strip, one end of the first line strip and one end of the second line strip are respectively connected to the two adjacent segments, and the other end of the first line strip and the other end of the second line strip are opposite to each other and arranged at intervals.

[0006] Furthermore, the first tape and the second tape are L-shaped.

[0007] Furthermore, the lengths of the first strip and the second strip are between 0.05 times and 0.25 times the high-frequency working wavelength that needs to be decoupled, and the gap between the first strip and the second strip is 0.3 mm to 2 mm.

[0008] Furthermore, the annular radiation arm is composed of a metal strip line, and the metal strip line and the first strip line and the second strip line are respectively arranged on two opposite sides of the radiator. A metallized via is opened on the radiator, and the metal strip line is connected to the first strip line or the second strip line through the metallized via hole.

[0009] Furthermore, a diagonal area of the annular radiation arm is provided with an adjustment structure for adjusting the array standing wave, and the adjustment structure includes three square copper foils of different sizes and one L-shaped arrow copper foil, and two adjacent adjustment structures are symmetrically arranged.

[0010] Furthermore, the feeding structure includes a first PCB feeding plate and a second PCB feeding plate, the metal copper foil at the ends of the first PCB feeding plate and the second PCB feeding plate are electrically connected to the array base plate, a first interlocking groove is provided on the first PCB feeding plate, and a second interlocking groove is provided on the second PCB feeding plate, and the first PCB feeding plate and the second PCB feeding plate are interlocked with each other through the first interlocking groove and the second interlocking groove to form an orthogonal structure.

[0011] Furthermore, a base station antenna is provided, which includes a main reflector, on which are distributed a plurality of low-frequency radiation units as described in any one of the above items and a plurality of high-frequency radiation units, the array base plate being arranged on a side of the main reflector away from the feeding structure, the array base plate being fixed to the main reflector by fasteners, and the array base plate being welded with a polarized cable.

[0012] Furthermore, the fastener is a nylon rivet.

[0013] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: the annular radiating arm of the present invention can maximize the current path aperture, effectively improve the unit gain, reduce the aperture while keeping the gain unchanged, and can be used to achieve antenna miniaturization. In addition, the first line strip and the second line strip are equivalent to low-pass filters, forming a path for the low-frequency current on the annular radiating arm and having an inhibitory effect on the high-frequency current, thereby achieving a spatial decoupling function and effectively solving the high- and low-frequency mutual coupling problem in the base station antenna. In addition, by installing the array base plate on the side of the main reflector away from the feeding structure, the array base plate and the main reflector are fixed by fasteners and the array base plate is welded with a polarized cable, which can solve the problem of the cable extending to the array radiating plate for welding in the past, and also avoid the coaxial cable from being affected by excessive bending in the electrical performance, thereby reducing the cable bending process in production. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the overall structure of the low-frequency radiation unit and the main reflector provided by an embodiment of the present invention;

[0015] Figure 2 yes Figure 1 Schematic diagram of the split structure;

[0016] Figure 3 yes Figure 1 Schematic diagram of the structure from another perspective.

[0017] In the accompanying drawings, each reference numeral represents:

[0018] 10. Radiator; 11. Ring-shaped radiating arm; 111. Segment; 112. Metal strip line; 121. First strip line; 122. Second strip line; 13. Metallized via; 141. Square copper foil; 142. Arrow-shaped copper foil; 20. Feed structure; 21. First PCB feed plate; 211. First fitting groove; 22. Second PCB feed plate; 221. Second fitting groove; 30. Array base plate; 40. Main reflector; 50. Fastener. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0020] like Figures 1 to 3 As shown, a low-frequency radiating unit provided by an embodiment of the present invention includes a radiator 10, a feeding structure 20, and an array base 30. One end of the feeding structure 20 is connected to the radiator 10 for feeding, and the other end of the feeding structure 20 is connected to the array base 30. The radiator 10 includes two pairs of orthogonally distributed annular radiating arms 11. The annular radiating arms 11 are respectively arranged in the ±45° direction of the radiator 10 to form two polarizations of ±45°. In other words, the four annular radiating arms 11 together constitute a dual-polarization radiating unit. The annular radiating arms 11 include multiple segments 111. Adjacent segments 111 are connected by a spatial decoupling structure. The spatial decoupling structure includes a first strip 121 and a second strip 122. One end of the first strip 121 and one end of the second strip 122 respectively connect the two adjacent segments 111. The other ends of the first strip 121 and the other ends of the second strip 122 are opposite to each other and spaced apart.

[0021] The annular radiating arm 11 of the present invention maximizes the current path area, effectively improving unit gain while reducing the aperture while maintaining the same gain, enabling antenna miniaturization. Furthermore, the first and second strips 121, 122 act as low-pass filters, forming a path for low-frequency currents in the annular radiating arm 11 and suppressing high-frequency currents, thereby achieving spatial decoupling and effectively resolving the problem of high- and low-frequency mutual coupling in base station antennas.

[0022] In this embodiment, the annular radiation arm 11 is composed of a metal strip line 112. The radiator 10 is divided into four equal parts and hollowed out on all sides to achieve lightweight. The metal strip line 112 forms a ring along the outer edge of the quarter aperture to maximize the current path aperture. The current path of the single arm of the radiation unit is about 0.25 wavelengths, which is 20% to 25% smaller than the cross array of the same type of feed to achieve the same gain size. The number of segments 111 is determined based on the operating frequency band of the low-frequency radiation unit and the operating frequency band of the high-frequency radiation unit to ensure that the length of each segment 111 is less than 0.25 times the operating wavelength of the high-frequency unit. By selecting a reasonable number of segments 111, the radiation arm segments 111 are broken up, so that the electromagnetic waves cannot resonate and scatter on the low-frequency unit, that is, the stealth function is achieved for the high frequency.

[0023] Preferably, the metal strip line 112, the first strip line 121, and the second strip line 122 are respectively arranged on opposite sides of the radiator 10. The radiator 10 is provided with a metallized via 13, through which the metal strip line 112 is connected to the first strip line 121 or the second strip line 122. The first strip line 121 and the second strip line 122 are L-shaped, with the length of the first strip line 121 and the second strip line 122 ranging from 0.05 times to 0.25 times the high-frequency operating wavelength to be decoupled. The gap between the first strip line 121 and the second strip line 122 is 0.3 mm to 2 mm. It should be noted that by adjusting the size, gap, and position of the metallized via 13, the spatial decoupling performance at a specific frequency can be optimized, and multiple frequency points can be optimized, thereby achieving a spatial broadband decoupling effect.

[0024] In addition, the diagonal area of the annular radiation arm 11 is provided with an adjustment structure for adjusting the array standing wave. The adjustment structure includes three square copper foils 141 of different sizes and an L-shaped arrow copper foil 142. The two adjacent adjustment structures are symmetrically arranged, thereby adjusting the array standing wave.

[0025] Optionally, the feeding structure 20 includes a first PCB feeding plate 21 and a second PCB feeding plate 22. The metal copper foil at the ends of the first PCB feeding plate 21 and the second PCB feeding plate 22 are electrically connected to the array base plate 30. A first interlocking groove 211 is provided on the first PCB feeding plate 21, and a second interlocking groove 221 is provided on the second PCB feeding plate 22. The first PCB feeding plate 21 and the second PCB feeding plate 22 are interlocked with each other through the first interlocking groove 211 and the second interlocking groove 221 to form an orthogonal structure. The first PCB feeding plate 21 and the second PCB feeding plate 22 respectively feed the two polarized radiation arms.

[0026] Another embodiment of the present invention provides a base station antenna comprising a main reflector 40, on which are distributed a plurality of low-frequency radiating elements and a plurality of high-frequency radiating elements as described in the above technical solution. An array base plate 30 is disposed on a side of the main reflector 40 facing away from the feed structure 20. The array base plate 30 and the main reflector 40 are secured by fasteners 50. A polarized cable is welded to the array base plate 30, thereby resolving the conventional issue of extending the cable to the array radiating element for welding. This also prevents excessive bending of the coaxial cable, which can affect its electrical performance, and reduces the number of cable bending steps in production. Optionally, the fasteners 50 are nylon rivets.

[0027] In summary, the annular radiation arm 11 of the present invention can maximize the current path opening, effectively improve the unit gain, reduce the aperture while keeping the gain unchanged, and can be used to achieve antenna miniaturization. In addition, the first line strip 121 and the second line strip 122 are equivalent to low-pass filters, forming a path for the low-frequency current on the annular radiation arm 11, and have an inhibitory effect on the high-frequency current, thereby achieving a spatial decoupling function and effectively solving the high- and low-frequency mutual coupling problem in the base station antenna. In addition, by installing the array base plate 30 on the side of the main reflector 40 away from the feeding structure 20, the array base plate 30 and the main reflector 40 are fixed by fasteners 50 and the array base plate 30 is welded with a polarized cable, which can solve the problem of the cable extending to the array radiation plate for welding in the past, and also avoid the coaxial cable from being affected by excessive bending and affecting the electrical performance, thereby reducing the cable bending process in production.

[0028] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A low-frequency radiation unit, characterized in that: The invention comprises a radiator (10), a feeding structure (20) and an array base plate (30), wherein one end of the feeding structure (20) is connected to the radiator (10) and performs feeding, and the other end of the feeding structure (20) is connected to the array base plate (30), the radiator (10) comprises two pairs of orthogonally distributed annular radiating arms (11), the annular radiating arms (11) comprise a plurality of segments (111), and two adjacent segments (111) are connected via a spatial decoupling structure, the spatial decoupling structure comprises a first line strip (121) and a second line strip (122), one end of the first line strip (121) and one end of the second line strip (122) are respectively connected to two adjacent segments (111), and the other end of the first line strip (121) and the other end of the second line strip (122) are opposite to each other and are spaced apart; The annular radiation arm (11) is composed of a metal strip line (112), the metal strip line (112) and the first strip line (121) and the second strip line (122) are respectively arranged on two opposite sides of the radiator (10), the radiator (10) is provided with a metallized via hole (13), and the metal strip line (112) is connected to the first strip line (121) or the second strip line (122) through the metallized via hole (13); The first line strip (121) and the second line strip (122) are used to form a path for the low-frequency current on the annular radiation arm (11) and to suppress the high-frequency current, thereby achieving spatial decoupling.

2. The low-frequency radiation unit according to claim 1, wherein: The first line belt (121) and the second line belt (122) are L-shaped.

3. The low-frequency radiation unit according to claim 2, characterized in that: The lengths of the first line strip (121) and the second line strip (122) are between 0.05 times and 0.25 times of the high-frequency working wavelength required for decoupling, and the gap between the first line strip (121) and the second line strip (122) is 0.3 mm to 2 mm.

4. The low-frequency radiation unit according to claim 1, wherein: The diagonal area of the annular radiation arm (11) is provided with an adjustment structure for adjusting the array standing wave, the adjustment structure comprising three square copper foils (141) of different sizes and an L-shaped arrow copper foil (142), and two adjacent adjustment structures are symmetrically arranged.

5. The low-frequency radiation unit according to claim 1, wherein: The feeding structure (20) comprises a first PCB feeding plate (21) and a second PCB feeding plate (22); the metal copper foils at the ends of the first PCB feeding plate (21) and the second PCB feeding plate (22) are electrically connected to the array base plate (30); a first interlocking groove (211) is provided on the first PCB feeding plate (21); a second interlocking groove (221) is provided on the second PCB feeding plate (22); the first PCB feeding plate (21) and the second PCB feeding plate (22) are interlocked with each other through the first interlocking groove (211) and the second interlocking groove (221) to form an orthogonal structure.

6. A base station antenna, characterized in that: The base station antenna includes a main reflector (40), on which a plurality of low-frequency radiation units and a plurality of high-frequency radiation units as described in any one of claims 1 to 5 are distributed, the array base plate (30) is arranged on a side of the main reflector (40) away from the feeding structure (20), the array base plate (30) and the main reflector (40) are fixed by fasteners (50), and a polarized cable is welded to the array base plate (30).

7. The base station antenna according to claim 6, wherein: The fastener (50) is a nylon rivet.

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