Dual-polarized antenna unit with integrated balun structure

Abstract

The present invention discloses a dual-polarized antenna unit of an integrated balun structure, which includes: a radiation structure, which includes a radiator, an upper dielectric plate for supporting the radiator; a supporting base, which includes a lower dielectric plate, a feed line on the upper end surface of the lower dielectric plate, and a metal floor of the feed line on the lower end surface of the lower dielectric plate; a feed balun, the feed balun includes a single middle dielectric plate, a middle upper pad, a middle lower pad, a middle feed microstrip line, a balun line and a metal floor, the middle upper pad, the middle lower pad, the middle feed microstrip line, and the balun line are line total bearings, and the line total bearings and the metal floor are respectively arranged on both sides of the middle dielectric plate. The present invention ingeniously utilizes the splitting of the metal ground in the feed balun structure and the bending and crossing of the end to feed the antenna unit, thereby simplifying the traditional two cross-cross balun feeding structures into an integrated balun structure.

Description

Technical Field

[0001] The invention belongs to the technical field of mobile communications, and in particular relates to a dual-polarization antenna unit with an integrated balun structure. Background Art

[0002] Dual-polarized antennas can save the number of base station antennas (that is, save base station antenna resources), or in other words, they can improve the communication capacity of base stations under the same antenna resources. Therefore, they are the mainstream form of base station antennas today. In dual-polarized antennas, the antenna unit is usually composed of two sets of mutually orthogonal oscillators. Such an antenna unit usually includes: a radiator, two feed baluns, and a base of the antenna unit. In such a structural form, the two feed baluns are assembled in an orthogonal manner, which increases the complexity of assembly and increases costs. Summary of the invention

[0003] An object of the present invention is to provide a dual-polarization antenna unit with an integrated balun structure, which can reduce the cost and assembly complexity of the antenna unit while ensuring the radiation performance of the dual-polarization antenna unit.

[0004] To achieve the above object, the technical solution adopted by the present invention is: a dual-polarized antenna unit with an integrated balun structure, comprising:

[0005] A radiation structure, comprising a radiator, and an upper dielectric plate for supporting the radiator;

[0006] A supporting base, which includes a lower dielectric plate, a feeder circuit on the upper surface of the lower dielectric plate, and a metal floor of the feeder circuit on the lower surface of the lower dielectric plate;

[0007] It also includes a feeding balun, which is characterized in that the feeding balun includes a single middle dielectric board, a middle upper pad, a middle lower pad, a middle feeding microstrip line, a balun line and a metal floor, the middle upper pad, the middle lower pad, the middle feeding microstrip line and the balun line are line supports, and the line supports and the metal floor are respectively arranged on both sides of the middle dielectric board.

[0008] Optimally, there are four radiating arms and they are rotationally symmetric. The four radiating arms are respectively a first radiating arm, a second radiating arm, a third radiating arm and a fourth radiating arm. The first radiating arm and the third radiating arm constitute a polarized radiator, and the polarization direction is the arrangement direction of the first radiating arm and the third radiating arm; the second radiating arm and the fourth radiating arm constitute another polarized radiator, and the polarization direction is the arrangement direction of the second radiating arm and the fourth radiating arm. The polarization directions of the two radiators are perpendicular to each other.

[0009] Optimally, a rectangular upper through hole is provided at the center of the upper dielectric plate, and the top of the feeding balun is inserted into the upper through hole to feed the radiator.

[0010] Optimally, the first radiation arm, the second radiation arm, the third radiation arm and the fourth radiation arm have four pads at the center of the antenna unit, and the four pads are respectively a first pad, a second pad, a third pad and a fourth pad.

[0011] The optimized, middle and lower pad includes two on the left and right, namely the first middle and lower pad and the second middle and lower pad, which are located at the lower part of the feed balun, and the pad provides a welding point between the feed balun and the feed microstrip line on the supporting base; the middle and upper pad includes two on the left and right, namely the first middle and upper pad and the second middle and upper pad, which are located at the upper part of the feed balun, and the middle and upper pad provides a welding point between the feed balun and the radiation arm; the middle feed microstrip line includes the first middle feed microstrip line and the second middle feed microstrip line, which connect the middle and lower pad and the middle and upper pad of the feed balun, and provide a feed signal path for the two antenna units.

[0012] Optimally, the common part of the floor, the common ground of the first mid-feed microstrip line and the second mid-feed microstrip line, has a rectangular protrusion at the bottom, which is inserted into the strip hole of the supporting base and is electrically connected to the signal ground of the supporting base through welding.

[0013] Optimally, the floor is divided into two parallel metal grounds from the common part upwards, namely the first metal ground and the second metal ground, and the two first metal grounds and the second metal grounds are used as signal grounds of the first mid-feed microstrip line and the second mid-feed microstrip line respectively.

[0014] Optimally, the upper parts of the two parallel metal grounds are bent to form a cross structure, and the ends of the cross structure are a first cross pad and a second cross pad, and the two pads provide welding points for the feed balun and the radiation arm.

[0015] The optimized middle balun line includes two on the left and right, namely the first middle balun line and the second middle balun line. The upper end of each balun line is connected to the pad, and the lower end is connected to the first metal ground and the second metal ground respectively through metal vias.

[0016] Optimized, support base includes:

[0017] The first lower feeding microstrip line and the second lower feeding microstrip line have a circular pad with a via at one end, providing a connection mode with an external coaxial cable, and a square pad at the other end, which is welded to the first middle lower pad and the second middle lower pad on the feeding balun;

[0018] The lower dielectric plate supports the microstrip line and the floor;

[0019] The metal floor is a common signal ground line of the first lower feeding microstrip line and the second lower feeding microstrip line.

[0020] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: the present invention cleverly utilizes the splitting of the metal ground in the feeding balun structure and the bending and crossing of the end to feed the antenna unit, thereby simplifying the traditional two cross-crossed balun feeding structures into an integrated balun structure. By adjusting the structure of the feeding microstrip line and the floor, the isolation between the two polarization units can be optimized. The balun line is used to achieve the balancing effect of the feeding current between the two radiating arms of the antenna unit, and at the same time, a lightning protection measure of DC grounding is realized. The dual-polarized antenna unit with an integrated feeding balun structure proposed by the present invention can reduce the cost and assembly complexity of the antenna unit compared to traditional solutions while ensuring the antenna radiation performance, and has important engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Attached Figure 1 It is a stereogram of the present invention;

[0022] Attached Figure 2 It is an exploded view of the present invention;

[0023] Attached Figure 3 is a top view of the radiator;

[0024] Attached Figure 4 This is the main view of the feed balun;

[0025] Attached Figure 5 This is the rear view of the feed balun;

[0026] Attached Figure 6 This is the main view of the support base;

[0027] Attached Figure 7 The rear view of the support base. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with the embodiments shown in the accompanying drawings.

[0029] like Figure 1 As shown, the dual-polarized antenna unit of the present invention includes three parts: a radiation structure 1, a feed balun 2, and a support base 3. The detailed structure of each part is as follows Figure 2 As shown, the radiation structure 1 includes a radiator 11, an upper dielectric plate 12 for supporting the radiator 11, a feeding balun 2 includes a single middle dielectric plate 22, a main support line 21 and a metal floor 23 integrating a feeding microstrip line and a balun line, the main support line 21 and the metal floor 23 are respectively arranged on both sides of the middle dielectric plate 22, and a supporting base 3 includes a lower dielectric plate 32, a feeding line 31 on the upper end surface of the lower dielectric plate 32, and a metal floor 33 of the feeding line 31 on the lower end surface of the lower dielectric plate 32.

[0030] The radiation structure is mainly composed of a radiator 11 and an upper dielectric plate 12 supporting the radiator. The radiator is composed of four rotationally symmetrical radiation arms. Figure 3 As shown, the four radiating arms are respectively the first radiating arm 111, the second radiating arm 112, the third radiating arm 113 and the fourth radiating arm 114. The first radiating arm 111 and the third radiating arm 113 constitute a polarized antenna unit, and the polarization direction is the arrangement direction of the first radiating arm 111 and the third radiating arm 113; similarly, the second radiating arm 112 and the fourth radiating arm 114 constitute another polarized antenna unit, and the polarization direction is the arrangement direction of the second radiating arm 112 and the fourth radiating arm 114. The polarization directions of the two antenna units are perpendicular to each other.

[0031] The radiator in the present invention is made as follows Figure 3 The metal strip structure shown in FIG. has a wave-transmitting function. It is worth noting that based on this simple feeding balun structure (such as Figure 1 The radiator in 2) can be Figure 3 It can be in other forms. In other words, the balun structure is universal.

[0032] like Figure 3 As shown, a rectangular upper through hole 121 is provided at the center of the upper dielectric plate 12 supporting the radiator. The top of the feeding balun 2 is inserted into the upper through hole 121 to feed the four radiating arms.

[0033] The first radiation arm 111, the second radiation arm 112, the third radiation arm 113 and the fourth radiation arm 114 have four pads at the center of the antenna unit. The four pads are respectively the first pad 1111, the second pad 1121, the third pad 1131 and the fourth pad 1141. The pads are used to provide welding points for the feed balun passing through the upper through hole 121, so that the feed balun is electrically connected to the four radiation arms.

[0034] like Figure 2 As shown, the feeding balun is mainly composed of a feeding microstrip line 21, a floor 23 and a supporting dielectric plate 22. The feeding microstrip line 21 and the floor 23 are located on both sides of the dielectric plate 22. The feeding microstrip line 21 is composed of two groups of microstrip lines in mirror symmetry, and the two groups of microstrip lines feed two polarized antenna units respectively.

[0035] like Figure 4-5 As shown, the specific details of the feed balun include:

[0036] 1) The middle lower pad 211 includes two pads on the left and right, namely the first middle lower pad 2111 and the second middle lower pad 2112, which are located at the bottom of the feed balun and are part of the feed microstrip line. The pad 211 provides a welding point for the feed balun and the feed microstrip line on the support base.

[0037] 2) The middle upper pad 212 includes two left and right pads, namely the first middle upper pad 2121 and the second middle upper pad 2121, which are located at the upper part of the feed balun and are part of the feed microstrip line. The middle upper pad 212 provides a welding point for the feed balun and the radiation arm. Specifically, when the upper part of the feed balun is inserted into the upper through hole 121 of the radiator, the first middle upper pad 2121 of the feed balun is connected to the second pad 1121 on the second radiation arm 112 by soldering with tin, and the second middle upper pad 2122 of the feed balun is connected to the third pad 1131 on the third radiation arm 113 by soldering with tin.

[0038] 3) The middle feed microstrip line 213 includes two left and right sides, namely the first middle feed microstrip line 2131 and the second middle feed microstrip line 2132. It connects the middle lower pad 211 and the middle upper pad 212 of the feed balun, providing a feed signal path for the two antenna units. The line width of the middle feed microstrip line 213 can be variable, for example, the line width of some strip lines is narrower and the line width of some strip lines is wider, so as to achieve impedance matching of the antenna unit. Strip line branches can also be generated on the microstrip line to provide other functions, such as filtering functions.

[0039] 4) The common part 230 of the floor 23 is the common ground of the first mid-feed microstrip line 2131 and the second mid-feed microstrip line 2132. There is a rectangular convex block at the bottom thereof, which is inserted into the strip hole of the support base and is electrically connected to the signal ground of the support base through welding.

[0040] 5) The floor 23 is divided upward from the common part 230 into two parallel metal grounds, namely the first metal ground 231 and the second metal ground 232. The two first metal grounds 231 and the second metal ground 232 are used as signal grounds for the first mid-feed microstrip line 2131 and the second mid-feed microstrip line 2132, respectively. The two first metal grounds 231 and the second 232 are separated by a blank gap, the main function of which is to provide sufficient isolation for the two feeding signals. By optimizing the shape and size of the blank gap, higher isolation and impedance matching characteristics can be obtained.

[0041] 6) The upper parts of the two parallel metal grounds are bent to form a cross structure. The ends of the cross structure are the first cross pad 2312 and the second cross pad 2322. The two pads provide welding points for the feed balun and the radiation arm. Specifically, when the upper part of the feed balun is inserted into the upper through hole 121 of the radiator, the first cross pad 2312 is connected to the fourth pad 1141 on the fourth radiation arm 114 by soldering with tin, and the second cross pad 2322 is connected to the first pad 1111 on the first radiation arm 111 by soldering with tin.

[0042] 7) The middle balun line 214 includes two left and right lines, namely the first middle balun line 2141 and the second middle balun line 2142. Each balun line has its upper end connected to the pad, and its lower end is connected to the first metal ground 231 and the second metal ground 232 through metal vias. Specifically, the upper end of the first middle balun line 2141 is connected to the first middle upper pad 2121, and the lower end is connected to the first metal ground 231 through a metal via; the upper end of the second middle balun line 2142 is connected to the second middle upper pad 2122, and the lower end is connected to the second metal ground 232 through a metal via. The balun line has three functions: First, it acts as a short circuit for DC signals. Specifically, the DC signal is transmitted on the first middle feed microstrip line 2131, and it is directly transmitted to the first metal ground 231 through the first middle balun line 2141. This is a lightning protection measure. The second function is to balance the current. Specifically, from the first middle upper pad 2121 through the first middle balun line 2141, to the third middle pad 2311, and finally to the first cross pad 2312, the entire path is approximately half the wavelength of the antenna unit operating frequency, ensuring that the phases on the first middle upper pad 2121 and the first cross pad 2312 are opposite, balancing the current. The third function is to adjust its structure to optimize the impedance matching performance.

[0043] like Figure 6-7 As shown, the support base includes:

[0044] 1) The first lower feeding microstrip line 311 and the second lower feeding microstrip line 312 have a circular pad with a via at one end, providing a connection method with an external coaxial cable, and a square pad at the other end, which is welded to the first middle lower pad 2111 and the second middle lower pad 2112 on the feeding balun.

[0045] 2) The lower dielectric plate 32 serves to support the microstrip line and the floor.

[0046] 3) The metal floor 33 is a common signal ground line for the first lower feeding microstrip line 311 and the second lower feeding microstrip line 312 .

[0047] 4) Strip hole 34, which plays the role of fixing the feed balun. Specifically, the lower part of the feed balun is inserted into the strip hole 34, and the lower part of the common ground 230 of the feed balun is welded to the metal floor 33. The first lower feed microstrip line 311 and the second lower feed microstrip line 312 are welded to the first middle lower pad 2111 and the second middle lower pad 2112 on the feed balun through square pads.

[0048] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A dual-polarized antenna unit with an integrated balun structure, comprising: A radiation structure, comprising a radiator, and an upper dielectric plate for supporting the radiator; A supporting base, which includes a lower dielectric plate, a feeder circuit on the upper surface of the lower dielectric plate, and a metal floor of the feeder circuit on the lower surface of the lower dielectric plate; It also includes a feed balun, which is characterized in that: the feed balun includes a single middle dielectric plate, a middle upper pad, a middle lower pad, a middle feed microstrip line, a balun line and a metal floor, the middle upper pad, the middle lower pad, the middle feed microstrip line and the balun line are line supports, and the line supports and the metal floor are respectively arranged on both sides of the middle dielectric plate; The middle lower pad includes two pads on the left and right, namely the first middle lower pad and the second middle lower pad, which are located at the lower part of the feed balun; The middle upper pad includes two pads on the left and right, namely the first middle upper pad and the second middle upper pad, which are located at the upper part of the feed balun; The middle feed microstrip line includes a first middle feed microstrip line and a second middle feed microstrip line, which are connected to the middle lower pad and the middle upper pad of the feed balun to provide a feed signal path for two antenna units; The middle balun line includes two left and right lines, namely the first middle balun line and the second middle balun line. The upper end of each middle balun line is connected to the pad, and the lower end is connected to the first metal ground and the second metal ground respectively through a metal via; The upper end of the first middle balun line is connected to the first middle upper pad, and the lower end is connected to the first metal ground through a metal via; the upper end of the second middle balun line is connected to the second middle upper pad, and the lower end is connected to the second metal ground through a metal via; the DC signal is transmitted on the first middle feed microstrip line, and it is directly transmitted to the first metal ground through the first middle balun line, from the first middle upper pad through the first middle balun line, to the third middle pad, and finally to the first cross pad. The entire path is half the wavelength of the operating frequency of the antenna unit, ensuring that the phases on the first middle upper pad and the first cross pad are opposite.

2. The dual-polarized antenna unit with an integrated balun structure according to claim 1, characterized in that: The radiator has four radiating arms and is rotationally symmetrical. The four radiating arms are respectively a first radiating arm, a second radiating arm, a third radiating arm and a fourth radiating arm. The first radiating arm and the third radiating arm constitute a polarized radiating unit, and the polarization direction is the arrangement direction of the first radiating arm and the third radiating arm; the second radiating arm and the fourth radiating arm constitute another polarized radiating unit, and the polarization direction is the arrangement direction of the second radiating arm and the fourth radiating arm. The polarization directions of the two radiating units are perpendicular to each other.

3. The dual-polarized antenna unit with an integrated balun structure according to claim 1, characterized in that: A rectangular upper through hole is provided at the center of the upper dielectric plate, and the top of the feeding balun is inserted into the upper through hole to feed the radiator.

4. The dual-polarized antenna unit with an integrated balun structure according to claim 1, characterized in that: The first radiation arm, the second radiation arm, the third radiation arm and the fourth radiation arm have four pads at the center of the antenna unit, and the four pads are respectively a first pad, a second pad, a third pad and a fourth pad.

5. The dual-polarized antenna unit with an integrated balun structure according to claim 1, characterized in that: The common part of the floor is the common ground of the first mid-feed microstrip line and the second mid-feed microstrip line, and has a rectangular convex block at the bottom, which is inserted into the strip hole of the support base and is electrically connected to the signal ground of the support base through welding.

6. The dual-polarized antenna unit with an integrated balun structure according to claim 1, characterized in that: The floor is divided into two parallel metal grounds upward from the common part, namely the first metal ground and the second metal ground. The first metal ground and the second metal ground are respectively used as signal grounds of the first mid-feed microstrip line and the second mid-feed microstrip line.

7. The dual-polarized antenna unit with an integrated balun structure according to claim 1, characterized in that: The upper parts of the two parallel metal grounds are bent to form a cross structure, and the ends of the cross structure are a first cross pad and a second cross pad, and the two pads provide welding points for the feed balun and the radiation arm.

8. The dual-polarized antenna unit with an integrated balun structure according to claim 1, characterized in that: The support base includes: The first lower feeding microstrip line and the second lower feeding microstrip line have a circular pad with a via at one end, providing a connection mode with an external coaxial cable, and a square pad at the other end, which is welded to the first middle lower pad and the second middle lower pad on the feeding balun; The lower dielectric plate supports the microstrip line and the floor; The metal floor is a common signal ground line of the first lower feeding microstrip line and the second lower feeding microstrip line.

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