CN103337712B - A kind of antenna radiation unit and feed method thereof - Google Patents

Abstract

The invention relates to an antenna radiating unit, which comprises two pairs of dipole radiating units with orthogonal polarization, and each dipole radiating unit is respectively installed on a metal reflector through a balun; each balun includes a parallel phase Adjacent to the two supporting columns, each dipole radiating unit includes two unit arms symmetrically fixed on the two supporting columns; each dipole radiating unit has a coaxial A cable, the outer conductor of the coaxial cable is connected to one of the unit arms or the corresponding support column, and the inner conductor of the coaxial cable is connected to the other unit arm or the corresponding support column. Has one or more sections of outer conductor cut-off area. The antenna radiating unit provided by the invention has simple structure, convenient installation, simple feeding, good consistency, and easy production; it can well solve the impedance matching problem of the broadband antenna unit, and realize the optimization of the electrical performance of the antenna.

Description

Antenna radiating unit and feeding method thereof

technical field

The invention relates to the communication field, in particular to an antenna radiation unit and a feeding method thereof.

Background technique

With the development of mobile communication technology, modern communication systems have put forward higher and higher requirements for the indicators of dual-polarized base station antennas, especially gain, bandwidth characteristics, and processing technology.

The existing dual-polarized antenna units mainly adopt the following implementation schemes: the first one adopts two dipole antenna dipole structures with common points, interleaving and polarization orthogonality; the second one adopts the microstrip radiation unit , to achieve dual polarization through coupling or direct feeding; the third is to use two pairs of dipoles placed orthogonally to form an approximately square layout.

In a commonly used network communication system, the most commonly used horizontal half-power beamwidth of an antenna is 65 degrees. The above-mentioned first scheme is generally composed of conventional dipoles or folded dipoles, and a wide frequency bandwidth can be obtained through this form; however, the horizontal beam of the antenna dipole varies greatly with different frequencies, and the gain of the antenna dipole is relatively small. Low. In the second solution, the frequency bandwidth of the microstrip radiating unit is narrow, the isolation between the two ports is poor, the gain of the oscillator is not high, and the assembly is troublesome, making it difficult to achieve wide application.

Relatively speaking, the overall performance of the radiating unit using the third square layout is better, and the base station antenna of the two frequency bands can be realized by nesting, so it has received more attention. But this design still has many deficiencies. For example, the Chinese invention patent application with the application number 201010256784.6 discloses an antenna design scheme, in which the dual-polarized antenna radiation unit is composed of two pairs of dipoles, and the antenna radiation unit is coupled and fed by a feed sheet. This solution can better realize the impedance matching of the unit's wide frequency band, but it contains a large number of components and has a complex structure; if it is mass-produced, the consistency of the vibrator unit is difficult to control. It feeds the dipoles through the coupling feeding method, which easily leads to unbalanced cables on both sides of the radiation arm of a single dipole, which will eventually affect the radiation unit pattern of the entire dual-polarized antenna.

Contents of the invention

The purpose of the present invention is to provide an antenna radiation unit and its feeding method for the deficiencies in the prior art, which has a simple structure, convenient installation, simple feeding, good consistency, and easy production; and can well solve Impedance matching of broadband antenna elements to optimize the electrical performance of the antenna.

To achieve the above object, the present invention adopts the following technical solutions:

An antenna radiating unit installed on a metal reflector, including two pairs of dipole radiating units with orthogonal polarization, each dipole radiating unit is respectively installed on the metal reflector through a balun; each bar Lun includes two supporting columns arranged parallel and adjacent, and each dipole radiating unit includes two unit arms respectively fixed on the two supporting columns symmetrically; in each dipole radiating unit, there is a balun The set coaxial cable, the outer conductor of the coaxial cable is connected to one of the unit arms or the corresponding support column, the inner conductor of the coaxial cable is connected to the other unit arm or the corresponding support column, and the coaxial cable is connected to the other unit arm or the corresponding support column. There are one or more outer conductor cut-off areas on the axial cable.

In the cut-off area of the outer conductor on the coaxial cable, only the inner conductor and the medium or only the inner conductor are left.

The connection between each dipole radiating unit and the balun is located on the same reference plane; one end of the unit arm is fixedly connected to the support column, and the other end has a plate-shaped piece perpendicular to the reference plane, and all unit arms on the reference plane The projection encloses a centrally symmetrical polygon or circle.

The other end of the unit arm has a conical or polygonal plate-shaped part, and the middle part of the plate-shaped part has a hollow area.

The bottom ends of all the baluns are fixedly connected to a base, and are installed on the metal reflection plate through the base.

The top of each balun is also provided with a feed connection column, one end of the feed connection column is fixedly connected to the top of one of the support columns, the other end extends to the other support column, and is suspended near the top of the other support column The outer surface of the support column is provided with a groove along the extension direction; in each balun, the inner conductor of the coaxial cable is connected to the feed connection column, and the length extension part of the coaxial cable is arranged on another support column In the groove of , and the outer conductor is connected with the groove of another support column.

The two pairs of dipole radiation units are orthogonally combined to form a polarization direction of +/- 45 degrees.

Each pair of dipole radiating units is symmetrically distributed about the center of the reference plane; the two baluns connecting a pair of dipole radiating units are also symmetrically distributed about the center of the reference plane.

The length of the balun connected to each dipole radiation unit is 0.2-0.3 working wavelength.

The antenna radiating unit is formed by integral die-casting.

A method for feeding using the antenna radiating unit described above, comprising the following steps:

Select a coaxial cable with a characteristic impedance;

Cut off one or more sections of the outer conductor on the coaxial cable, and only the inner conductor and the medium or only the inner conductor are left in the part where the outer conductor is cut off;

Connect the inner conductor at one end of the coaxial cable to one of the supporting columns of the balun, arrange the length extension of the coaxial cable along the other supporting column, and the outer conductor is close to the other supporting column;

By adjusting the length and the number of sections of the cut-out part of the outer conductor on the coaxial cable, and the condition of the medium left in the cut-out part of the outer conductor, different requirements for impedance transformation are met.

The antenna radiating unit and its feeding method provided by the present invention can simply and effectively match the antenna impedance and easily increase the bandwidth, reduce antenna complexity, and reduce antenna cost. It has simple structure, convenient installation, simple feeding, good consistency, and easy production; and it can well solve the impedance matching problem of the broadband antenna unit and realize the optimization of the electrical performance of the antenna; it is especially suitable for GSM800, GSM900, CDMA800, LTE700, etc. 600~1000MHz mobile communication system.

Description of drawings

Fig. 1 is a schematic view of the use state of Embodiment 1 of the present invention.

FIG. 2 is a schematic structural diagram of Embodiment 1 of the present invention.

Fig. 3 is a schematic view of the bottom structure of Embodiment 1 of the present invention.

Fig. 4 is a schematic structural diagram of Embodiment 2 of the present invention.

Fig. 5 is a schematic structural diagram of Embodiment 3 of the present invention.

Detailed ways

The technical solutions of the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Embodiment one

As shown in FIG. 1 , an antenna radiation unit 11 provided by an embodiment of the present invention is used to be installed on a metal reflector 10 to form a mobile communication base station antenna. Wherein, the antenna radiating unit 11 includes two pairs of dipole radiating units with orthogonal polarization, and each dipole radiating unit is respectively installed on the metal reflector 10 through a balun (balanced-unbalanced converter) . Each dipole radiating unit respectively includes two unit arms symmetrically fixed on the balun. Wherein, each balun includes two supporting columns arranged in parallel and adjacently, and the two unit arms in each dipole radiating unit are symmetrically fixed on the two supporting columns respectively.

Specifically, in the embodiment of the present invention, the first unit arm 1a and the second unit arm 1b are fixed on the first balun 1, the third unit arm 2a and the fourth unit arm 2b are fixed on the second balun 2, The fifth unit arm 3 a and the sixth unit arm 3 b are fixed on the third balun 3 , and the seventh unit arm 4 a and the eighth unit arm 4 b are fixed on the fourth balun 4 . Wherein, the first unit arm 1a and the second unit arm 1b form the first dipole radiation unit, the third unit arm 2a and the fourth unit arm 2b form the second dipole radiation unit, the fifth unit arm 3a and the sixth unit arm 3a The unit arm 3b forms the third dipole radiation unit, and the seventh unit arm 4a and the eighth unit arm 4b form the fourth dipole radiation unit. The first dipole radiating unit and the third dipole radiating unit form a pair of dipole radiating units, and the second dipole radiating unit and the fourth dipole radiating unit form another pair of dipole radiating units; two pairs of dipoles The sub-radiating units are arranged in a polarization orthogonal manner, and combined to form a polarization direction of +/- 45 degrees.

Further, as shown in Figure 2, the connections between the dipole radiating units and the baluns are located on the same reference plane, that is, the first to fourth dipole radiating units are respectively connected to the same height of the first to fourth baluns Location. Specifically, one end of the unit arm is fixedly connected to the balun, and the other end of the unit arm has a tapered or polygonal plate-shaped piece perpendicular to the reference plane; two unit arms connected to the same balun form a certain angle and shape, so that the projections of all unit arms on the reference plane enclose a centrally symmetrical polygon or circle.

Correspondingly, the embodiment of the present invention has a center-symmetric structure as a whole, and each pair of dipole radiation units is symmetrically distributed about the center of the reference plane; the two baluns connecting a pair of dipole radiation units are also symmetrically distributed about the center of the reference plane. That is, the first dipole radiating unit and the third dipole radiating unit, the second dipole radiating unit and the fourth dipole radiating unit, the first balun 1 and the third balun 3, and the second balun 2 and the fourth balun 4 are respectively distributed symmetrically about the center of the reference plane.

Since the embodiment of the present invention has a centrosymmetric structure, the first dipole radiation unit and the first balun 1 are taken as examples for specific description here. The first balun 1 includes a first support column 111 and a second support column 112, one end of the first unit arm 1a and one end of the second unit arm 1b are respectively fixedly connected to the top ends of the first support column 111 and the second support column 112 , the other end of the first unit arm 1a and the other end of the second unit arm 1b are respectively a polygonal plate-shaped member, wherein the center of the plate-shaped member has a hollowed-out hollow area, and the outline of the hollow area is the same as that of the plate The outer contours of the plate-shaped part are parallel, so that the plate-shaped part becomes a polygonal frame. The first unit arm 1a and the second unit arm 1b are symmetrical with respect to the first balun 1 and form an included angle of 90° between them. The structure of the second to third dipole radiation units is the same as that of the first dipole radiation unit, and since the two pairs of dipole radiation units are arranged orthogonally in polarization, the first to eighth unit arms are on the reference plane The shape enclosed by the projection of is roughly square.

The lengths of the first to fourth baluns in the embodiment of the present invention are equal, and are 0.2-0.3 working wavelengths. The bottom ends of the first to fourth baluns are fixedly connected to the same circular base 9 , and then fixedly installed on the metal reflector 10 through the base 9 .

Further, in each dipole radiation unit, there is a coaxial cable arranged along the balun, the outer conductor of the coaxial cable is connected to one of the unit arms or the corresponding support column, and the coaxial cable The inner conductor is connected to another unit arm or a corresponding supporting column, and the coaxial cable has one or more sections of outer conductor cut-off areas. In the cut-off area of the outer conductor on the coaxial cable, only the inner conductor and the medium or only the inner conductor are left. The top of each balun is provided with a feed connection column, one end of the feed connection column is fixedly connected to the top of one of the support columns of the balun, and the other end extends to the other support column, and is suspended from the other support column Near the top; the outer surface of the support column is provided with grooves along the extending direction. In each balun, the inner conductor of the coaxial cable is connected to the feed connection column, the length extension part of the coaxial cable is arranged in the groove of another support column, and the outer conductor is connected to the other support column. Grooves are connected.

Specifically, as shown in Figure 2 and Figure 3, the tops of the first to fourth baluns are respectively erected with an L-shaped first feed connecting column 8, a second feeding connecting column 5, and a third feeding connecting column 6 and the fourth feed connecting column 7. Since the structures of the first to fourth baluns are the same, the first balun is taken as an example for illustration. One end of the first feed connection column 8 is fixedly connected to the top of the second support column 112 , the other end extends to the first support column 111 and is suspended near the top of the first support column 111 . The outer surfaces of the first supporting column 111 and the second supporting column 112 are provided with grooves along the extension direction for laying the coaxial cable 12 . In the embodiment of the present invention, a coaxial cable 12 with a characteristic impedance of Z1 is selected. The inner conductor 120 of the coaxial cable 12 arranged on the first balun 1 is connected to the first feed connecting column 8; the length extension part of the coaxial cable 12 is arranged in the groove of the first supporting column 111, And the outer conductor 122 is closely connected with the groove of the first support column 111 . The coaxial cable 12 has a multi-section outer conductor cut-off area 121 , and the medium in the outer conductor cut-off area 121 is also cut off, leaving only the inner conductor 120 . Therefore, the cut-out region 121 of the outer conductor matches the metal of the groove of the first support post 111 to form a transmission line with a characteristic impedance Z2. By adjusting the number of sections and the length of each section in the outer conductor cut-off area 121, the transmission lines with characteristic impedances Z1 and Z2 can transform the unit impedance of the antenna radiation unit, and finally output the impedance required by the antenna of the mobile communication base station.

As an improvement, the antenna radiating unit 11 in the embodiment of the present invention may be integrally molded.

Embodiment two

As shown in FIG. 4 , the embodiment of the present invention is a modified structure of the first embodiment. The first to fourth baluns in the embodiment of the present invention are not integrated through a base, but are separately installed on the metal reflector.

Other structures of this embodiment of the present invention are the same as those of Embodiment 1, and will not be repeated here.

Embodiment three

As shown in FIG. 5 , the embodiment of the present invention is a modified structure of the first embodiment. In each dipole radiation unit in the embodiment of the present invention, the angle between the two unit arms fixedly connected to the upper end of the balun is an obtuse angle, so that the projection shape of all the unit arms on the reference plane is a centrally symmetrical polygon. It should be noted that, in combination with Embodiment 1, the included angles between the two unit arms in each dipole radiation unit in the present invention can be various angles, and the projection of the unit arms on the reference plane can also be a curve, only the final guarantee The projections of all the unit arms on the reference plane enclose a centrally symmetrical polygon or circle.

In particular, in the embodiment of the present invention, the coaxial cable 12 whose characteristic impedance is Z1 is selected. The inner conductor 120 of the coaxial cable 12 arranged on the first balun 1 is connected to the first feed connecting column 8; the length extension part of the coaxial cable 12 is arranged in the groove of the first supporting column 111, And the outer conductor 122 is closely connected with the groove of the first support column 111 . The coaxial cable 12 has a plurality of outer conductor cutout areas, specifically, the outer conductor cutout area includes a first outer conductor cutout area 124 and a second outer conductor cutout area 123 . The outer conductor 122 and the medium in the first outer conductor cut-off area 124 are cut off, leaving only the inner conductor 120; in the second outer conductor cut-off area 123, only the outer conductor 122 is cut off, and the medium and inner conductor 120 is reserved. Therefore, the first outer conductor cut-off region 124 matches the metal of the groove of the first support pillar 111 to form a transmission line with a characteristic impedance of Z2; the second outer conductor cut-off region 123 matches the metal of the groove of the first support pillar 111 Match to form a transmission line with characteristic impedance Z3. By adjusting the number of segments and the length of each segment in the cut-off area of the first and second outer conductors, the transmission lines with characteristic impedances of Z1, Z2, and Z3 can transform the unit impedance of the antenna radiation unit, and finally output the required signal for the antenna of the mobile communication base station impedance.

Other structures of this embodiment of the present invention are the same as those of Embodiment 1, and will not be repeated here.

The present invention also provides a feeding method using the above-mentioned antenna radiating unit, which specifically includes the following steps:

Select a coaxial cable with a characteristic impedance;

Cut off one or more sections of the outer conductor on the coaxial cable, and only the inner conductor and the medium or only the inner conductor are left in the part where the outer conductor is cut off;

Connect the inner conductor at one end of the coaxial cable to one of the supporting columns of the balun, arrange the length extension of the coaxial cable along the other supporting column, and the outer conductor is close to the other supporting column;

By adjusting the length and the number of sections of the cut-out part of the outer conductor on the coaxial cable, and the condition of the medium left in the cut-out part of the outer conductor, different requirements for impedance transformation are met.

The antenna radiating unit and its feeding method provided by the present invention can simply and effectively match the antenna impedance and easily increase the bandwidth, reduce antenna complexity, and reduce antenna cost. It has simple structure, convenient installation, simple feeding, good consistency, and easy production; and it can well solve the impedance matching problem of the broadband antenna unit and realize the optimization of the electrical performance of the antenna; it is especially suitable for GSM800, GSM900, CDMA800, LTE700, etc. 600~1000MHz mobile communication system.

The above-mentioned embodiments only express several implementation modes of the present invention, and the description thereof is relatively specific and detailed, but should not be construed as limiting the patent scope of the present invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (11)

1. an antenna radiation unit, is installed on metallic reflection plate, it is characterized in that, comprise the dipole radiating element that two pairs of polarization orthogonal are arranged, each dipole radiating element is installed on metallic reflection plate respectively by a Ba Lun; Each Ba Lun comprises parallel two support columns be disposed adjacent, and each dipole radiating element comprises two the unit arms be individually fixed in symmetrically on two support columns; In each dipole radiating element, there is a coaxial cable arranged along Ba Lun, the outer conductor of described coaxial cable connects with one of them unit arm or corresponding support column, the inner wire of coaxial cable connects with another unit arm or corresponding support column, described coaxial cable has a joint or more piece outer conductor cut-away area; Described outer conductor cut-away area is in the centre of coaxial cable.

2. antenna radiation unit according to claim 1, is characterized in that, the outer conductor cut-away area on described coaxial cable, only leaves inner wire and medium or only leaves inner wire.

3. antenna radiation unit according to claim 1, is characterized in that, the junction of each dipole radiating element and Ba Lun is positioned at same reference planes; One end of unit arm is fixedly connected on support column, and the other end has the plate-like piece perpendicular to described reference planes, and the projection on the reference plane of all unit arms surrounds centrosymmetric polygon or a circle.

4. antenna radiation unit according to claim 3, is characterized in that, the other end of unit arm has taper or polygon plate-like piece, and the middle part of plate-like piece has a hollow region.

5. antenna radiation unit according to claim 1, is characterized in that, the bottom of all Ba Lun is fixedly connected on a base, and by floor installation on metallic reflection plate.

6. antenna radiation unit according to claim 1, it is characterized in that, the top of each Ba Lun is also provided with feed joint pin, and one end of described feed joint pin is fixedly connected on a wherein support column top, the other end extends to another support column, and is unsettledly located near another support column top; The outer surface of support column offers groove along bearing of trend; In each Ba Lun, the inner wire of described coaxial cable is connected with feed joint pin, and the length extension of coaxial cable is arranged in the groove of another support column, and outer conductor is connected with the groove of another support column.

7. antenna radiation unit according to claim 1, is characterized in that, the mutually orthogonal combination of the sub-radiating element of described two electrode couple, forms the polarised direction of +/-45 degree.

8. antenna radiation unit according to claim 1, is characterized in that, the sub-radiating element of every electrode couple distributes about the Central Symmetry of reference planes; Two Ba Lun connecting a pair dipole radiating element also distribute about the Central Symmetry of reference planes.

9. antenna radiation unit according to claim 1, is characterized in that, the Ba Lun length that each dipole radiating element connects is 0.2 ~ 0.3 operation wavelength.

10. antenna radiation unit according to claim 1, is characterized in that, the integrated die cast of described antenna radiation unit.

11. 1 kinds of methods using the antenna radiation unit described in claim 1 to carry out feed, is characterized in that, comprise the following steps:

Choose the coaxial cable with a characteristic impedance;

By the joint on coaxial cable or the excision of more piece outer conductor portion, the cut part of outer conductor only leaves inner wire and medium or only leaves inner wire;

The inner wire of coaxial cable one end is connected with a wherein support column of Ba Lun, the length extension of coaxial cable is arranged along another support column, and outer conductor is close on another support column;

By length and the joint number of the outer conductor cut-out on adjustment coaxial cable, and outer conductor cut-out leaves the situation of medium, meets different impedance transformation demands.