CN105449361A - Broad-band dual polarization base station antenna unit - Google Patents

Abstract

The invention proposes a broadband dual-polarization base station antenna unit, which is used to solve the problems of poor structural stability and complex technical process of the existing dual-polarization base station antenna unit; it includes a radiator (1), a first feed balun (2 ), the second feed balun (3), the base (4) and the reflector (5); the first feed balun (2) and the second feed balun (3) are orthogonal to each other, the two feed The top of the electric balun (2,3) is installed with a radiator (1) perpendicular to it, and the bottom end is respectively connected with a radio frequency cable (6); the reflector (5) is fixed with a base (4), and the first feed bar The top and bottom of the balun (2) and the second feeding balun (3) are respectively provided with two rectangular protrusions for connecting the radiator (1) and the base (4). The invention has the advantages of simple structure, convenient processing, wide frequency band, high isolation and good direction diagram, and can be used for miniaturized base station antennas in new generation communication systems.

Description

Broadband Dual Polarization Base Station Antenna Unit

technical field

The invention belongs to the technical field of mobile communication, and relates to a broadband dual-polarization base station antenna unit, in particular to a broadband dual-polarization base station antenna unit with simple structure and convenient processing, which can be used for mobile communication base station antenna arrays.

Background technique

The base station refers to the radio transceiver station that transmits information between the mobile communication switching center and the mobile terminal in a certain radio coverage area. Among them, the antenna, as one of the most important components in the base station, is mainly responsible for the communication equipment. Electrical signals and space radiated electromagnetic waves are converted. Base station antenna design is very important in base station applications. Base station antennas can be divided into single-polarization and dual-polarization base station antennas according to the polarization mode. For traditional single-polarized antennas, when the number of antennas increases, due to the isolation between antennas and space diversity technology, there must be horizontal and vertical separation distances between antennas. At this time, the platform for installing antennas must be expanded, which increases infrastructure investment. When dual-polarization technology is used, the polarization orthogonality of ±45° can ensure that the isolation between +45° and -45° antennas meets the requirements of intermodulation for the isolation between antennas to be ≥30dB, and the dual-polarization antenna The space interval between them only needs to be 20-30cm, so the mobile base station does not need to build an iron tower, but only needs to erect an iron pillar with a diameter of 20cm, and fix the dual-polarized antenna on the iron pillar according to the corresponding coverage direction. In addition, the dual-polarization antenna has the advantages of reducing call loss, reducing interference, and high service quality. At present, the common working frequency bands of dual-polarized base station antennas are: 1880-1920MHz, 2010-2025MHz, 2300-2400MHzTD-SCDMA; 1610-1880MHzDCS; 1850-1990MHzPCS; 1920-2160MHzUMTS, etc. In order to take into account the above-mentioned frequency bands of different standards, the market needs a broadband base station antenna that can cover 1710-2690MHz, and requires it to have stable performance, for example, the working frequency band ∣S11∣ is greater than 14dB, and the half-power lobe width of the radiation pattern H surface satisfies 65°±10°, isolation greater than 23dB, front-to-back ratio greater than 20dB, etc.

For the base station antenna processing technology, the printed antenna has been widely used in the base station antenna because of its simple processing and low cost. Existing broadband dual-polarized base station antennas printed on dielectric boards, such as the document "ACompactDual-PolarizedPrintedDipoleAntennawithHighIsolationforWidebandBaseStationApplications" published by YanshanGou, ShiwenYang, JinxinLi, and ZaipingNie on IEEETrans. This document proposes a broadband printed base station antenna unit. The antenna unit consists of three printed dielectric boards and a reflector. Among them, two pairs of half-wave oscillators with vertical polarization directions formed by four triangular patches are printed on the lower surface of the upper dielectric board and welded together with two mutually perpendicular feeding dielectric boards. The feed dielectric board is printed with a Γ-shaped microstrip line on the front and ground on the back. The feeding dielectric plates perpendicular to each other act as balanced excitations to the two pairs of half-wave oscillators on the upper dielectric plate. The upper dielectric plate where the half-wave vibrator is located and the feed dielectric plate are supported on the reflector by four plastic columns. This antenna has the following disadvantages: On the one hand, it is difficult to weld the half-wave vibrator on the lower surface of the upper dielectric plate to the ground on the back of the feeding dielectric plate, and manual welding is difficult to ensure that the longitudinal symmetry axis of the half-wave vibrator on the upper dielectric plate is aligned with the corresponding feeding medium. The coincidence of the centerlines in the thickness direction of the board will cause processing errors and affect the broadband and radiation performance of the antenna. On the other hand, due to the use of additional supports, the stability and performance of the antenna are easily affected by the outside world.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned defects in the prior art, and propose a broadband dual-polarization base station antenna unit, which is used to solve the problems of poor structural stability and complex technical process of the existing dual-polarization base station antenna unit.

For realizing above-mentioned purpose, the technical scheme that the present invention takes is:

A broadband dual-polarized base station antenna unit, comprising a radiator 1, a first feeding balun 2, a second feeding balun 3 and a reflector 5, the first feeding balun 2 and the second feeding balun The luns 3 are orthogonal to each other, the top is installed with a radiator 1 perpendicular to it, and the bottom end is respectively connected with a radio frequency cable 6; the reflector 5 is fixed with a base 4; the first feed balun 2 and the second feed balun The top and bottom of the balun 3 are respectively provided with two rectangular protrusions for connecting the radiator 1 and the base 4 .

The aforementioned broadband dual-polarized base station antenna unit, the radiator 1 includes a radiator dielectric plate 16 and two pairs of half-wave vibrators printed on the upper surface of the radiator dielectric plate 16, these two pairs of half-wave vibrators are orthogonal to each other, each The half-wave vibrator is composed of the same two vibrators 11, and a cross gap 17 is etched between the four vibrators 11 for adjusting impedance matching; the vibrator 11 adopts a square structure with arc-shaped cut corners 12 on the diagonal , on the other diagonal, there are fan-shaped slits 13 etched; the shape of the radiator dielectric plate 16 is a square, and a first rectangular slit 14 and a second rectangular slit are arranged on its two diagonals 15, for mounting two feed baluns 2,3.

The aforementioned broadband dual-polarized base station antenna unit, the first feed balun 2, includes a rectangular first dielectric plate 21, a feeder 22 printed on the upper surface of the first dielectric plate 21, and two feeders on the lower surface. The ground 23 , 24 ; the top and the bottom of the first dielectric board 21 are respectively provided with rectangular protrusions; the longitudinal central axis of the first dielectric board 21 is provided with a long groove line 25 .

The above-mentioned broadband dual-polarization base station antenna unit, the second feed balun 3, includes a rectangular second dielectric plate 31, a feeder 32 printed on the upper surface of the second dielectric plate 31, and two feeders on the lower surface. The ground 23, 24; the top and the bottom of the second medium plate 31 are respectively provided with rectangular protrusions; the longitudinal central axis of the second medium plate 31 is provided with a short groove line 33 for connecting with the long groove line 25 Cooperate.

For the broadband dual-polarization base station antenna unit, the base 4 includes a square base dielectric plate 41 and a metal patch 42 printed on its lower surface; the two diagonals of the base dielectric plate 41 are respectively provided with a second Three rectangular slits 43 are used to cooperate with the rectangular protrusions at the bottom ends of the first feeding balun 2 and the second feeding balun 3 .

For the above-mentioned broadband dual-polarization base station antenna unit, the reflector 5 is made of lightweight conductive material, and its four sides are provided with vertically upward convex edges for improving the radiation characteristics of the antenna unit.

Compared with the prior art, the present invention has the following advantages:

1. The top of the feeding balun dielectric plate of the present invention is provided with a rectangular protrusion, which is used to cooperate with the first rectangular slit and the second rectangular slit on the radiator dielectric plate, and to be electrically connected to the half-wave vibrator on its upper surface, The bottom end is also provided with a rectangular protrusion for matching with the third rectangular gap on the base dielectric plate and electrically connecting with the metal patch on the lower surface, which has the advantage of structural stability.

2. The two feeding baluns of the present invention are perpendicular to each other and are respectively inserted into the radiator dielectric plate and the base to ensure that the longitudinal symmetry axis of the half-wave oscillator on the radiator dielectric plate coincides with the centerline in the thickness direction of the corresponding feeding dielectric plate. Strictly orthogonal dual-polarized radiation is formed and high isolation is achieved.

3. Among the two pairs of half-wave vibrators in the present invention, the vibrators of each pair of half-wave vibrators adopt a square structure with a circular arc cut corner on one diagonal, and a fan-shaped slit is etched on the diagonal of the other diagonal. While achieving higher bandwidth of the antenna unit, the volume of the radiator is reduced.

Description of drawings

Fig. 1 is the overall structural representation of the present invention;

Fig. 2 is a structural schematic diagram of a radiator of the present invention;

Fig. 3 is a structural schematic diagram of the first balun of the present invention;

Fig. 4 is the structural representation of the second balun of the present invention;

Fig. 5 is a schematic structural view of the base of the present invention;

Fig. 6 is the simulation figure of S parameter of the present invention;

Fig. 7 is the direction diagram of the H plane at different frequency points of the present invention.

detailed description

Below in conjunction with accompanying drawing and specific embodiment the present invention is described in further detail:

Referring to Fig. 1, the present invention comprises radiator 1, first feeding balun 2, second feeding balun 3, base 4, reflector 5 and radio frequency cable 6; Said first feeding balun 2 and second The feeding baluns 3 are orthogonal to each other; the first feeding balun 2 is used to feed the corresponding half-wave oscillator on the radiator 1, similarly, the second feeding balun 3 is used to feed the radiator 1 The corresponding half-wave vibrator is fed to achieve polarization in two vertical directions; the top and bottom of the first feeding balun 2 and the second feeding balun 3 are each provided with two rectangular protrusions, It is used to install the radiator 1 and the base 4 perpendicular to it; the base 4 and the reflector 5 are connected by non-metallic fixing parts, and this embodiment uses plastic rivets; the reflector 5 is made of light-weight conductive materials, and this embodiment uses a A square aluminum plate with vertical upward convex edges on its four sides is used to improve the radiation characteristics of the antenna unit; the radiator 1, the base 4 and the reflector 5 are all square and parallel to each other; the first feeding balun 2 and the second The two feeding baluns 3 are rectangular with protrusions, and are perpendicular to the radiator 1, the base 4 and the reflector 5; the radiator 1, the first feeding balun 2, the second feeding balun 3 and the base 4 Both are installed in the center of the reflector 5, and are symmetrical about its geometric center; two 50-ohm radio frequency cables 6 are respectively connected with the first feeding balun 2 and the second feeding balun 3; the inner cores of the radio frequency cables 6 are respectively connected with The feeder 22 on the upper surface of the first feeder balun 2 is welded to the feeder 32 on the upper surface of the second feeder balun 3 , and the outer cores are respectively welded to the metal patch 42 on the lower surface of the base 4 .

Referring to FIG. 2, the radiator 1 includes a radiator dielectric plate 16 and two pairs of half-wave oscillators printed on the upper surface of the radiator dielectric plate 16. The radiator dielectric plate 16 adopts FR with a dielectric constant of 4.4 and a thickness of 0.8 mm. -4 square dielectric plates; two pairs of half-wave vibrators on the radiator dielectric plate 16 are orthogonal to each other, and are fed by their corresponding baluns to realize ±45° dual polarization; each pair of half-wave vibrators is composed of the same two Composed of four vibrators 11, cross slits 17 are etched between the four vibrators 11 for adjusting impedance matching; the vibrator 11 adopts a square structure with arc-shaped cut corners 12 on one diagonal, and a square structure on the other diagonal. On the corner, there are fan-shaped slits 13 etched; specifically, the center of the fan-shaped slit 13 is set at a position along the diagonal of the radiator dielectric plate 16 and close to its geometric center, the central angle is 90°, and the radius of the fan-shaped slit 13 is along the The two central axes of the radiator dielectric plate 16 extend outward; the centers of the arc-shaped cut corners 12 are respectively set on the other diagonal of the vibrator 11 perpendicular to the symmetry axis of the fan-shaped gap 15, and on the diagonal end points of the line, and respectively inwardly etch a quarter circle; by adjusting the size of the arc-shaped cut corner 12 and the fan-shaped slit 13, the antenna can cover the required bandwidth; the shape of the radiator dielectric plate 16 is a square, A first rectangular slit 14 and a second rectangular slit 15 are provided on its two diagonals for installing two feeder baluns 2 , 3 .

Referring to Fig. 3, the first feed balun 2 includes a first dielectric plate 21, a feeder line 22 printed on the upper surface of the first dielectric plate 21 and two grounds 23, 24 on the lower surface for feeding the radiator dielectric plate The corresponding half-wave vibrator on 16 is fed; the first dielectric plate 21 adopts a FR-4 square dielectric plate with a dielectric constant of 4.4 and a thickness of 0.8mm; The two grounds 23 and 24 on the lower surface of the board 21 cooperate to realize the unbalanced to balanced conversion of the current and realize broadband impedance matching; the top of the first dielectric board 21 is provided with two rectangular protrusions with a metal coating on the back for use Cooperate with the first rectangular slit and the second rectangular slit on the radiator dielectric plate 16, and weld it to the half-wave vibrator on the upper surface; the bottom end of the first dielectric plate 21 is also provided with two metal-clad rectangular The protrusion is used to cooperate with the third rectangular gap on the base medium plate 41 and to weld with the metal patch 42 on the lower surface; the position of the protrusion is suitable to ensure the stability of the structure, and the length of the protrusion is generally selected as 3-8mm , the height is generally selected as 2-5 mm; a long groove line 25 is arranged on the longitudinal central axis of the first dielectric plate 21, and the length of the long groove line 25 cannot exceed the height of the feeder line 22 on the upper surface.

Referring to Fig. 4, the second feed balun 3 includes a second dielectric plate 31, a feeder line 32 printed on the upper surface of the second dielectric plate 31 and two grounds 23, 24 on the lower surface for feeding the radiator dielectric plate The corresponding half-wave vibrator on 16 is fed; the width and height of the second feed balun 3 are equal to the first feed balun 2; the second dielectric plate 31 adopts FR- 4 square dielectric plates; the feeder 32 adopts a two-section tapered microstrip line structure, and cooperates with the two grounds 23 and 24 on the lower surface of the second dielectric plate 31 to realize the conversion from unbalanced to balanced current and realize broadband impedance matching; The top of the second dielectric plate 31 is provided with two rectangular protrusions with a metal coating on the back, which are used to cooperate with the first rectangular slit and the second rectangular slit on the radiator dielectric plate 16, and weld with the half-wave oscillator on the upper surface ; The bottom end of the second dielectric plate 31 is also provided with two rectangular protrusions with a metal coating on the back, which are used to cooperate with the third rectangular gap on the base dielectric plate 41 and weld with the metal patch 42 on the lower surface; The position of the protrusion should be able to ensure the stability of the structure. The length of the protrusion is generally 3-8mm, and the height is generally 2-5mm; The length of the length cannot exceed the height of the upper surface feeder 32; the length of the long slot line 25 and the short slot line 33 should be the height of the first feed balun 2 or the second feed balun 3; the long slot The width of the line 25 and the short groove line 33 is generally selected to be 0.8-1mm, so that the first dielectric board 21 and the second dielectric board 31 can be easily clamped together, and they are perpendicular to each other while maintaining the same height.

Referring to FIG. 5 , the base 4 is formed by printing a metal patch 42 on the back of a square dielectric plate 41; the square 41 adopts an FR-4 dielectric plate with a dielectric constant of 4.4 and a thickness of 0.8 mm; the base dielectric plate 41 On the two diagonals of , there are respectively provided third rectangular slits 43 for cooperating with the rectangular protrusions at the bottom ends of the first feeding balun 2 and the second feeding balun 3 .

Below in conjunction with simulation result, technical effect of the present invention is further described:

1. Simulation content

1.1 Use the commercial simulation software High Frequency Structure Simulator HFSS ver.13) to simulate and calculate the S parameters in the range of 1.5-3GHz, and the results are shown in Figure 6.

1.2 Perform simulation calculations on the far-field radiation pattern of this embodiment at 1.7GHz, 1.9GHz, 2.1GHz, 2.3GHz, 2.5GHz and 2.7GHz. The radiation pattern of the dual-polarized base station antenna unit in the embodiment on the H plane is shown in Figure 7 shown.

2. Simulation results

Referring to Fig. 6, when |S ₁₁ | is greater than 15dB, the antenna of the present invention has a working frequency band of 1.65GHz-2.74GHz, a relative bandwidth of 49.7%, and an in-band isolation of greater than 24.1dB. It shows that the present invention has good impedance bandwidth characteristics. Moreover, due to the orthogonal feeding method, there is good isolation between the half-wave oscillators.

Referring to Fig. 7, the H-plane half-power lobe width of the present invention is maintained at 67.96°±7.34°, and the 60° cross-polarization ratio is less than -21dB, which meets the unidirectionality requirement of the base station antenna unit.

The above simulation results show that the present invention has the advantages of wide frequency band, high isolation, dual polarization, and stable radiation performance under the premise of simple structure and convenient processing.

The above descriptions and embodiments are only preferred examples of the present invention, and do not constitute any limitation to the present invention. Obviously, for those skilled in the art, after understanding the contents and design principles of the present invention, it is possible to In the case of principle and structure, various amendments and changes in form and details are made, but these amendments and changes based on the idea of the present invention are still within the protection scope of the claims of the present invention.

Claims (6)

1. a wideband dual polarized base station antenna unit, comprise radiant body (1), the first feed Ba Lun (2), the second feed Ba Lun (3) and reflecting plate (5), described first feed Ba Lun (2) and the second feed Ba Lun (3) is mutually orthogonal, top is provided with perpendicular radiant body (1), and bottom is connected to radio frequency cable (6); It is characterized in that, described reflecting plate (5) is fixed with base (4); The top of described first feed Ba Lun (2) and the second feed Ba Lun (3) and bottom, be respectively provided with two rectangular preiections, for connecting radiant body (1) and base (4).

2. wideband dual polarized base station antenna unit according to claim 1, it is characterized in that, described radiant body (1) comprises radiant body dielectric-slab (16) and is printed on the HBV"liang dui ban" ripple oscillator of this radiant body dielectric-slab (16) upper surface, this HBV"liang dui ban" ripple oscillator is mutually orthogonal, often pair of half-wave dipole is made up of identical two oscillators (11), between four oscillators (11), etching has cross gap (17), for regulating impedance matching; Described oscillator (11) adopts a diagonal angle to be provided with the square structure of circular arc corner cut (12), and on the diagonal at another diagonal angle, etching has fan-shaped gap (13); The shape of described radiant body dielectric-slab (16) is square, two diagonal is provided with the first rectangular aperture (14) and the second rectangular aperture (15), for installing two feed Ba Lun (2,3).

3. wideband dual polarized base station antenna unit according to claim 1, it is characterized in that, described first feed Ba Lun (2), comprise two ground (23,24) of the first medium plate (21) that shape is rectangle, the feeder line (22) being printed on this first medium plate (21) upper surface and lower surface; Top and the bottom of described first medium plate (21) are respectively provided with rectangular preiection; Described first medium plate (21) longitudinal central axis line is provided with an elongated slot line (25).

4. wideband dual polarized base station antenna unit according to claim 1, it is characterized in that, described second feed Ba Lun (3), comprise two ground (23,24) of the second medium plate (31) that shape is rectangle, the feeder line (32) being printed on this second medium plate (31) upper surface and lower surface; Top and the bottom of described second medium plate (31) are respectively provided with rectangular preiection; Described second medium plate (31) longitudinal central axis line is provided with a short line of rabbet joint (33), for coordinating with elongated slot line (25).

5. wideband dual polarized base station antenna unit according to claim 1, is characterized in that, described base (4) comprises square base dielectric-slab (41) and is printed on the metal patch (42) of its lower surface; On two diagonal of described base dielectric-slab (41), be respectively arranged with the 3rd rectangular aperture (43), for coordinating with the rectangular preiection of the first feed Ba Lun (2) and the second feed Ba Lun (3) bottom.

6. wideband dual polarized base station antenna unit according to claim 1, is characterized in that, described reflecting plate (5) adopts lightweight conductive material, and its four limit is provided with convex edge vertically upward, for improving antenna element radiation characteristic.