A balun structure, a radiation unit and an antenna

Abstract

The present invention relates to the field of mobile communication antennas, and provides a balun structure and a radiation unit and antenna thereof, wherein the balun structure comprises a first support plate, on which a first balun and a first director located above the first balun are provided; a second support plate, on which a second balun and a second director located above the second balun are provided; the first support plate and the second support plate are cross-arranged, and the first support plate and the second support plate are provided with one end of the first director and the second director respectively for connecting to a radiation surface, and the other end respectively for connecting to the ground. The present invention integrates a director on the support plate of the balun structure, and increases the bandwidth of the radiation unit and antenna using the balun structure without changing the structure and size of the support plate. At the same time, there is no need to add other components, the product consistency is good, the cost can be greatly reduced, and it is conducive to the miniaturization of the radiation unit and the antenna.

Description

Technical Field

[0001] The present invention relates to the field of mobile communication antennas, and more specifically, to a balun structure and a radiation unit and an antenna thereof. Background Art

[0002] With the large-scale commercial use of 5G mobile communication systems, the telecom 800MHz LTE networking, and the continuous expansion and improvement of the mobile 2.6GHz TDD 4G network, the original 900MHz and 1800MHz 2G and 3G networks have been withdrawn one after another, which has led to the re-planning of base station antenna resources. In order to improve the utilization rate of antenna resources, 4G and 5G antennas will not develop independently, but will inevitably gradually merge and develop together. Among them, one of the challenges will be that multi-band and multi-standard radiating units coexist in the same antenna, and the radiating units will interfere with each other seriously.

[0003] In order to solve the problem of mutual interference between radiating units, the prior art can effectively reduce mutual interference by reducing the diameter of the radiating unit and filtering the corresponding frequency band. However, a small-diameter radiating unit cannot effectively widen the bandwidth.

[0004] As an important device for balanced conversion of radiating unit feed, improving the balun to solve the problem that small-aperture radiating units cannot effectively widen the bandwidth has important research significance and broad application prospects. Summary of the invention

[0005] The present invention aims to overcome the problem that the small-aperture radiation unit in the prior art cannot effectively widen the bandwidth, and provides a balun structure for achieving the purpose of expanding the bandwidth of the radiation unit and antenna using the new balun without increasing the size.

[0006] The technical solution adopted by the present invention is to provide a balun structure, including a first supporting plate, on which a first balun and a first director located above the first balun are provided; a second supporting plate, on which a second balun and a second director located above the second balun are provided; wherein the first supporting plate and the second supporting plate are cross-arranged, and the first supporting plate and the second supporting plate are provided with one end of the first director and the second director respectively for connecting to the radiation surface, and the other end respectively for connecting to the ground.

[0007] This solution guides energy to the radiation surface by respectively arranging the first director and the second director on the first balun and the second balun, thereby effectively increasing the bandwidth of the radiation unit and the antenna using the balun structure. More importantly, the first director and the first balun are arranged on the same support sheet, and the second director and the second balun are arranged on the same support sheet, and the original structure and size of the existing support sheet are not changed or affected in any way. Instead, the director component is only added on the basis of the structure and size of the existing support sheet, which simply increases the bandwidth of the radiation unit and the antenna using the balun structure. Furthermore, this solution has wide applicability. Since there is no need to design a new technical solution for the radiation unit or other components in the antenna to match the balun structure, the existing components can be used to form a radiation unit or antenna together with the new balun, which also greatly reduces the cost.

[0008] Preferably, the first director and the second director each include at least one microstrip line. In this solution, the balun structure can guide the energy to the radiation surface through the microstrip line, which is simple and convenient. Moreover, the microstrip line structure can conveniently make full use of the space of the support sheet for flexible layout, thereby facilitating the miniaturization of the radiation unit.

[0009] Preferably, the uppermost microstrip line of the first support sheet and / or the second support sheet extends to the top of the support sheet where it is located. In this way, it is more conducive to the connection with the radiation unit. In this solution, when the first support sheet and / or the second support sheet is connected to the radiation surface, the microstrip line is arranged in this way, and the energy can be better guided directly to the radiation surface via the uppermost microstrip line, and the structure is simple and compact, and it is easy to process.

[0010] Preferably, the line width of the microstrip line of the first director and / or the second director is 2 mm to 3 mm. The line width range adopted in this solution enables the microstrip line to better guide energy to the radiation surface.

[0011] Preferably, the first director and / or the second director are each provided with at least two sections of microstrip lines, and on the same director, the distance between adjacent microstrip lines is one sixteenth to one eighth of the central wavelength. In this scheme, according to electromagnetic wave theory, when a metal body is close to the excitation, the electromagnetic wave energy will be coupled to the metal body and conducted along the arrangement direction of the metal body. This is the principle of the director. This scheme can obtain a stronger coupling effect through this distance, so that the microstrip line can better guide the energy to the radiation surface. If the distance between adjacent microstrip lines is too close, the microstrip lines will increase a lot, and the energy formed will easily obtain high-order modes, and this application is to obtain the main mode of the energy field; if the distance between adjacent microstrip lines is too far, the coupling effect is reduced and the energy obtained is weaker.

[0012] Preferably, the distance between the first balun and / or the second balun and the closest microstrip line is one eighth of the central wavelength. This scheme can obtain a stronger coupling effect through this distance, so that the microstrip line can better guide energy to the radiation surface. The central wavelength is the central wavelength of the working frequency band of the radiation unit.

[0013] Preferably, the microstrip lines on the first support sheet and the second support sheet are respectively arranged in a direction away from the first balun and the second balun, and the lengths of the microstrip lines on the first support sheet and / or the second support sheet are the same. In this solution, the microstrip lines are arranged in this way to obtain a stronger coupling effect, so that the microstrip lines can better guide energy to the radiation surface.

[0014] Preferably, between adjacent microstrip lines on the first support sheet and / or the second support sheet, the length of the microstrip line farther from the first balun or the second balun is 0.8 times the length of the microstrip line closer to the first balun or the second balun. This solution enables the microstrip line to better guide energy to the radiation surface through this length ratio. The length of the microstrip line can be set according to actual requirements so that the bandwidth of the radiation unit and antenna using the new balun meets the requirements.

[0015] A radiation unit includes a balun structure; a radiation sheet disposed on the balun structure; wherein the first director and the second director are connected to the radiation sheet and guide energy from the first balun and the second balun to the radiation sheet respectively. In this solution, the radiation unit uses the balun structure, which effectively expands the bandwidth of the radiation unit and makes it more in line with the needs of practical applications.

[0016] Preferably, the radiation sheet is provided with four radiation arms, and the four radiation arms form two pairs of cross-polarized symmetrical oscillators; the radiation arms are provided with a plurality of radiation branches, and adjacent radiation branches are connected by double U-shaped lines. In this solution, the line is arranged in this way to obtain a better low-frequency array filtering effect.

[0017] An antenna includes a radiation unit. In this solution, the antenna uses the balun structure, which effectively expands the bandwidth of the antenna and makes it more in line with the needs of practical applications.

[0018] Compared with the prior art, the present invention has the following beneficial effects: by integrating a director on the support sheet of the balun structure, the present invention increases the bandwidth of the radiation unit and antenna using the balun structure without changing the structure and size of the support sheet, and at the same time, no additional components are required, the product consistency is good, the cost can be greatly reduced, and it is conducive to the miniaturization of the radiation unit and the antenna. In addition, the present invention also optimizes the director so that the director can better guide energy to the radiation surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural diagram of the first supporting sheet 1.

[0020] Figure 2 It is a structural diagram of the second supporting sheet 2.

[0021] Figure 3 It is a schematic diagram of assembling the first supporting sheet 1 and the second supporting sheet 2.

[0022] Figure 4 This is the structural diagram of the radiation unit.

[0023] Figure 5 It is a structural diagram of the radiation plate 3.

[0024] Figure 6 It is the standing wave diagram of the radiation unit.

[0025] Figure 7 This is the structural diagram of the antenna.

[0026] Figure 8 This is a traditional balun structure diagram.

[0027] Figure numerals: 1. first supporting plate; 11. first balun; 111. first feeding point; 12. first director; 121. first microstrip line; 122. second microstrip line; 13. first protrusion; 14. first groove; 2. second supporting plate; 21. second balun; 211. second feeding point; 22. second director; 221. third microstrip line; 222. fourth microstrip line; 23. second protrusion; 24. second groove; 3. radiating plate; 31. radiating arm; 311. first circuit; 312. second circuit; 313. third circuit; 314. first U-shaped line; 315. second U-shaped line; 316. through hole; 4. power divider. DETAILED DESCRIPTION

[0028] The drawings of the present invention are only for illustrative purposes and should not be construed as limiting the present invention. In order to better illustrate the following embodiments, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; it is understandable to those skilled in the art that some well-known structures and their descriptions in the drawings may be omitted.

[0029] Example 1

[0030] The present embodiment provides a balun structure. In order to facilitate the understanding of the balun structure provided by the embodiment of the present application, its application scenario is first described below. The balun structure is applied to a radiation unit and an antenna. The first support sheet 1 and the second support sheet 2 are the substrate of the balun structure, and are important components of the radiation unit and the antenna. The first support sheet 1 and the second support sheet 2 are cross-arranged, one end of which is connected to the radiation surface, and the other end is connected to the ground. The first support sheet 1 and the second support sheet 2 can be PCB support sheets, or they can be dielectric support sheets formed by a dielectric substrate. The radiation surface can be provided by a radiation unit such as a PCB radiation unit, a patch radiation unit, a metal die-cast radiation unit, or a plastic metallized radiation unit. The ground refers to a grounding surface.

[0031] Among them, Figure 1 As shown, the first support sheet 1 has two faces, namely the front face and the back face. A first balun 11 is arranged on the front face of the first support sheet 1. In order to increase the bandwidth of the radiation unit and the antenna using the new balun, a first director 12 is arranged on the front face of the first support sheet 1 to better guide the electromagnetic wave energy from the first balun 11 to the radiation surface. Specifically, the first director 12 is arranged above the first balun 11, and both the first balun 11 and the first director 12 can be made of metal. A metal layer is arranged on the back face of the first support sheet 1, and the metal layer is used for grounding. In order to enable the first support sheet 1 to be connected to the radiation surface, a first protrusion 13 is arranged at the top of the first support sheet 1. There are two first protrusions 13, but not limited to only two. In order to enable the first support sheet 1 and the second support sheet 2 to be arranged crosswise, the first support sheet 1 is provided with a first groove 14, and the first groove 14 extends from the outside of the top end of the first support sheet 1 to the inside to the top of the first balun 11. The first balun 11 has a first feeding point 111. The first balun 11 is in an open circuit state.

[0032] Among them, Figure 2As shown, the second support sheet 2 is substantially the same as the first support sheet 1. Specifically, a second balun 21 and a second director 22 located above the second balun 21 are provided on the front of the second support sheet 2. The second support sheet 2 is also provided with a second protrusion 23 and a second groove 24. Specifically, the second protrusion 23 is also provided at the top of the second support sheet 2, and there are two second protrusions 23, but not limited to only two; different from the first support sheet 1, the second groove 24 extends from the outside of the bottom end of the second support sheet 2 to the inside to the bottom of the second balun 21. A metal layer is provided on the back of the second support sheet 2. The second balun 21 has a second feeding point 211. The second balun 21 is in an open circuit state.

[0033] like Figure 3 As shown, the first support sheet 1 and the second support sheet 2 are respectively snapped together through the first groove 14 and the second groove 24 to achieve the purpose of cross setting. During assembly, based on the first support sheet 1, the second support sheet 2 is rotated 90° and snapped into the first support sheet 1; after assembly, the balun structure is in an "X" shape, and the first feeding point 111 and the second feeding point 211 are respectively located at the two poles of the balun structure. Since the backs of the first support sheet 1 and the second support sheet 2 are provided with a metal layer, after assembly, the first feeding point 111 and the second feeding point 211 will not contact each other, so that the electromagnetic waves of the first feeding point 111 and the second feeding point 211 can be isolated to avoid mutual interference, thereby improving the polarization isolation.

[0034] In addition, in some embodiments, the first support sheet 1 and the second support sheet 2 may be integrally formed to further simplify the manufacturing process.

[0035] Specifically, in order to enable the first director 12 and the second director 22 to better adapt to the actual requirements of the radiation unit and the antenna, the first director 12 and the second director 22 each include at least one section of microstrip line.

[0036] Specifically, in order to better extend the energy to the radiation surface via the microstrip line and reduce the cost, the uppermost microstrip line of the first support sheet 1 and / or the second support sheet 2 extends to the top of the support sheet where it is located. In detail, the uppermost microstrip line of the first support sheet 1 extends to the first protrusion 13. The uppermost microstrip line of the second support sheet 2 extends to the second protrusion 23.

[0037] Specifically, in order to enable the microstrip line to better guide the energy to the radiation surface, the relevant parameters of the microstrip line are set. In order to more conveniently explain the microstrip line, the microstrip line on the first support sheet 1 is used for explanation. In the embodiment of the present application, the first director 12 is described as having two microstrip lines, and the two microstrip lines are respectively the first microstrip line 121 and the second microstrip line 122; the second director 22 is also provided with a third microstrip line 221 and a fourth microstrip line 222 at approximately the same position on the second support sheet 2 corresponding to the first microstrip line 121 and the second microstrip line 122. In detail, the microstrip lines on the first support sheet 1 and the second support sheet 2 are respectively arranged in turn away from the first balun 11 and the second balun 21. Taking the first director 12 as an example, the distance between the second microstrip line 122 and the first balun 11 is greater than the distance between the first microstrip line 121 and the first balun 11. The lengths of the microstrip lines on the first support sheet 1 and / or the second support sheet 2 may be the same. In detail, the line width of the microstrip line of the first director 12 and / or the second director 22 is 2mm-3mm. In detail, the first director 12 and / or the second director 22 are each provided with at least two sections of microstrip lines, and on the same director, the distance a between adjacent microstrip lines is one-sixteenth to one-eighth of the center wavelength. Taking the first director 12 as an example, the distance a between the first microstrip line 121 and the second microstrip line 122 is one-sixteenth to one-eighth of the center wavelength. In detail, the distance b between the first balun 11 and / or the second balun 21 and the closest section of the microstrip line is one-eighth of the center wavelength. Taking the first director 12 as an example, the distance b between the first balun 11 and the first microstrip line 121 is one-eighth of the center wavelength. The embodiments of the present application can obtain a strong coupling effect through both the distance a and the distance b. The lengths of the microstrip lines on the same support sheet may also be different. Between adjacent microstrip lines on the first support sheet 1 and / or the second support sheet 2, the length of the microstrip line farther from the first balun 11 or the second balun 21 is 0.8 times the length of the microstrip line closer to the first balun 11 or the second balun 21. Taking the first director 12 as an example, the length of the second microstrip line 122 is 0.8 times the length of the first microstrip line 121. In addition, since the first groove 14 extends from the outside of the top of the first support sheet 1 to the inside to the top of the first balun 11, in this case, the microstrip line on the first support sheet 1 is separated by the first groove 14.

[0038] Example 2

[0039] like Figure 4As shown, this embodiment provides a radiation unit, including the balun structure in embodiment 1; a radiation sheet 3, which is arranged on the balun structure; wherein the first director 12 and the second director 22 are connected to the radiation sheet 3 and respectively guide the energy from the first balun 11 and the second balun 21 to the radiation sheet 3. The radiation sheet 3 can be a half-wave array or a folded array, and the form of the radiation sheet 3 does not affect the new balun.

[0040] Among them, Figure 5 As shown, the radiation plate 3 may be a symmetrical structure. The radiation plate 3 is provided with four radiation arms 31, and the four radiation arms constitute two pairs of cross-polarized symmetrical oscillators. The radiation arm 31 is provided with a plurality of radiation branches, and the adjacent radiation branches are connected by a double U-shaped line. One of the radiation arms 31 is used as an example for explanation. The radiation arm 31 is provided with a plurality of radiation branches, and the radiation branches are circuits, namely, a first circuit 311, a second circuit 312, and a third circuit 313. The first circuit 311, the second circuit 312, and the third circuit 313 are arranged in sequence, and the first circuit 311, the second circuit 312, and the third circuit 313 are connected by the double U-shaped line. The double U-shaped line is formed by two sections of U-shaped lines arranged symmetrically, and the two sections of U-shaped lines are respectively a first U-shaped line 314 and a second U-shaped line 315, and the first U-shaped line 314 and the second U-shaped line 315 have the same structure.

[0041] The radiation plate 3 is provided with four through holes 316 for connecting to the balun structure for feeding.

[0042] The novel balun is respectively clamped in the through hole 316 of the radiation plate 3 through the first protrusion 13 and the second protrusion 23 and then connected by welding.

[0043] like Figure 6 As shown, the radiating unit after adopting the traditional balun structure has a frequency band coverage range of 700MHz-810MHz under the requirement of standing wave less than 1.6; while the radiating unit after adopting the new balun has a frequency band coverage range of 700MHz-950MHz under the requirement of standing wave less than 1.6, and its coverage range is twice that of the traditional balun structure.

[0044] Example 3

[0045] like Figure 7 As shown, this embodiment provides an antenna, including the radiation unit as described in Example 2; and also includes a power divider 4.

[0046] The first supporting plate 1 and the second supporting plate 2 are respectively provided with the first director 12 and the second director 22, one end of which is respectively connected to the radiating plate 3, and the other end is respectively connected to the power divider 4, so as to play the role of unbalanced-balanced conversion and impedance matching.

[0047] Specifically in this embodiment, the power divider 4 is a one-to-two power divider.

[0048] like Figure 8 As shown, the conventional balun structure in the prior art is partially consistent with the balun structure in Example 1. The balun structure is different from the conventional balun structure in that the first director 12 and the second director 22 are missing.

[0049] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the technical solution of the present invention, and are not intended to limit the specific implementation methods of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the claims of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A balun structure, characterized in that: include A first supporting plate (1) on which a first balun (11) and a first director (12) located above the first balun (11) are provided; A second supporting plate (2), on which a second balun (21) and a second director (22) located above the second balun (21) are provided; The first supporting sheet (1) and the second supporting sheet (2) are arranged crosswise, and the first supporting sheet (1) and the second supporting sheet (2) are provided with the first director (12) and the second director (22), one end of which is respectively used to be connected to the radiation surface, and the other end of which is respectively used to be connected to the ground; The first director (12) and / or the second director (22) each include at least one section of microstrip line; The first director (12) and / or the second director (22) are both provided with at least two sections of microstrip lines, and on the same director, the distance between adjacent microstrip lines is one sixteenth to one eighth of the central wavelength.

2. A balun structure according to claim 1, characterized in that: The uppermost section of the microstrip line of the first supporting plate (1) and / or the second supporting plate (2) extends to the top of the supporting plate where it is located.

3. A balun structure according to claim 1, characterized in that: The line width of the microstrip line of the first director (12) and / or the second director (22) is 2 mm-3 mm.

4. A balun structure according to claim 1, characterized in that: The distance between the first balun (11) and / or the second balun (21) and the closest microstrip line is one eighth of the central wavelength.

5. A balun structure according to any one of claims 1 to 4, characterized in that: The microstrip lines on the first support plate (1) and the second support plate (2) are respectively arranged in a direction away from the first balun (11) and the second balun (21), and the microstrip lines on the first support plate (1) and / or the second support plate (2) have the same length.

6. A balun structure according to any one of claims 1 to 4, characterized in that: Between adjacent microstrip lines on the first supporting plate (1) and / or the second supporting plate (2), the length of the microstrip line farther from the first balun (11) or the second balun (21) is 0.8 times the length of the microstrip line closer to the first balun (11) or the second balun (21).

7. A radiation unit, characterized in that: include The balun structure according to any one of claims 1 to 6; A radiation plate (3), arranged on the balun structure; The first director (12) and the second director (22) are connected to the radiation plate (3) and guide energy from the first balun (11) and the second balun (21) to the radiation plate (3) respectively.

8. A radiation unit according to claim 7, characterized in that: The radiation plate (3) is provided with four radiation arms (31), and the four radiation arms constitute two pairs of cross-polarized symmetrical oscillators; the radiation arms (31) are provided with a plurality of radiation branches, and adjacent radiation branches are connected by double U-shaped lines.

9. An antenna, characterized in that: include A radiation unit as claimed in any one of claims 7 to 8.

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