CN103066376B - Broadband high-isolation dual-polarized antenna and radiating element thereof - Google Patents

Abstract

The invention discloses a broadband high-isolation dual-polarized antenna and a radiation unit thereof, wherein the radiation unit comprises a reflecting plate, a first feed element, a second feed element, a first radiation body, a second radiation body and four support elements, wherein the first radiation body and the second radiation body are both composed of two diagonal radiation bodies; the four radiating bodies are respectively fixed on the four supporting pieces, the four supporting pieces are fixed on the reflecting plate, the tops of the first feed piece and the second feed piece are mutually orthogonal and have a height difference, the first feed piece is a feed structure of the first radiating body, the second feed piece is a feed structure of the second radiating body, and a cross-shaped gap is formed among the four radiating bodies; the middle position of each radiator surface is provided with a rectangular branch section which is longer than the radiator and faces the outer side edge of the radiator, and the outer side edge of each radiator is provided with the branch section. The dual-polarized antenna radiation unit and the antenna array formed by the dual-polarized antenna radiation unit have the advantages of high isolation, strong radiation characteristic, wide frequency band and the like.

Description

A wide-band high-isolation dual-polarized antenna and its radiating unit

technical field

The invention relates to a dual-polarization antenna, in particular to a wide-band high-isolation dual-polarization antenna and a radiation unit thereof.

Background technique

In recent years, with the rapid development of mobile communication, the communication system will inevitably develop from 2G and 3G communication systems to 4G communication systems. Due to the importance of broadband base station antennas in communication systems, the design of broadband base station antennas that meet LTE communication systems become a recent research hotspot. At present, the research on broadband base station antennas at home and abroad mainly focuses on the performance, cost, and assembly of base station antennas.

In order to improve the capacity of the communication system, the polarization diversity technology is generally adopted, and the working efficiency of the antenna is improved by designing a wide-band dual-polarization antenna. One of the difficulties in designing a broadband dual-polarized antenna is to control the mutual influence between two differently polarized antennas while making each polarized antenna meet the operating characteristics, which affects the isolation and cross-polarization of the antenna. and other indicators are required. Improving the isolation of dual-polarized antennas is mainly to reduce the current influence between the two feed ports by designing a reasonable feed mode. The smaller the current influence between the two ports, the greater the isolation of the antenna. In engineering design Generally, the isolation is improved by making the two feeders orthogonal to each other. Another difficulty in designing a broadband dual-polarized antenna is that not only the impedance matching bandwidth of the antenna is required to meet the requirements of a wide frequency band (such as 1.71-2.69GHz), but the radiation characteristics of the antenna are also required to meet the requirements within this wide frequency range. .

The electrical length of different frequencies will change with the frequency. In a wide frequency band, the electrical length will change greatly, but the physical size of the final design of the antenna remains unchanged. Therefore, it is very challenging to design an antenna that satisfies broadband operation with a constant physical size and length.

Contents of the invention

The object of the present invention is to overcome the shortcomings and deficiencies of the prior art, and provide a dual-polarized antenna radiation unit with strong radiation characteristics, high isolation and wide frequency bandwidth.

Another object of the present invention is to obtain a wide-band high-isolation dual-polarization antenna by using the above-mentioned dual-polarization antenna radiating unit.

The first object of the present invention is achieved through the following technical solutions: a wide-band high-isolation dual-polarized antenna radiation unit, including a reflector, a first feeder, a second feeder, a first radiator, a second Two radiators and four supports, the first radiator and the second radiator are composed of two diagonal radiators; the four radiators are respectively fixed on the four supports, and the four The supporting member is fixed on the reflector, the tops of the first feeding member and the second feeding member are orthogonal to each other, and there is a height difference, the first feeding member is a feeding structure of the first radiator, The second feeding part is the feeding structure of the second radiator, and a cross-shaped gap is formed in the middle of the four radiators; the middle position of each radiator is provided with a length longer than the radiator and facing the outer edge of the radiator. Rectangular branches in the direction, and branches are provided on the outer edge of each radiator.

Preferably, the part of the rectangular branches whose length exceeds the radiator is bent vertically downward; the rectangular branches on the surfaces of the four radiators are orthogonal to each other; and the structures, shapes and sizes of the four radiators are the same.

Preferably, the branches on the outer edge of the radiator are arc-shaped, and the four radiators form a circular structure.

Preferably, the branches on the outer edge of the radiator are rectangular, and the four radiators form a square structure.

Preferably, both the first feeder and the second feeder are "Γ" type metal feeders.

Furthermore, the four supports are hollow metal cylinders in the middle;

The four supports are respectively the first support, the second support, the third support and the fourth support, and the four supports are distributed on the four corners of the square, wherein the first support and The positions of the third support are relative, and the positions of the second support and the fourth support are relative;

The top of the first feeder passes through the first support and is fixedly connected to the third support, and the top of the second feeder passes through the second support and is fixedly connected to the fourth support;

The bottoms of the first feeder and the second feeder are respectively connected to the middle probes of the two SMA connectors, and the outer conductors of the two SMAs are connected to the reflector.

Furthermore, there are gaps at the top of the four supports, and the top of the first feeder passes through the first support and is connected to the notch of the third support by welding, and the second feeder After passing through the second support, the top of the piece is connected to the notch of the fourth support by welding.

Preferably, the four supporting members are independently fixed on the reflecting plate by welding.

The first object of the present invention is achieved through the following technical solutions: a wide-band high-isolation dual-polarized antenna includes at least two dual-polarized antenna radiation units, and a plurality of dual-polarized antenna radiation units adopt power The sub-networks are jointly fed to form an antenna array.

Preferably, inner flanging and outer flanging are installed on the edge of the reflecting plate.

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

(1) The radiator surface of the dual-polarized antenna radiating unit of the present invention is provided with rectangular branches. In the radiation part, since the current is mainly distributed on the edge surfaces of the radiator on both sides of the middle gap, it is distributed on the rectangular branches of the radiator surface and the outside of the radiator. The current on the edge branches is very small, so the rectangular branches on the surface of the radiator and the branches on the outer edge of the radiator have little influence on the radiation characteristics of the radiator. Therefore, the radiation performance of the antenna can be well adjusted by parameters such as the length or width of the cross-shaped slot, so that it can reach a required radiation index.

(2) The dual-polarized antenna radiation unit of the present invention has two resonance points within the working frequency range of 1.71-2.69GH, and the first resonance point is a low-frequency resonance point, which means that each dual-polarized antenna radiation unit inherently works The resonance point corresponding to the frequency is related to the electrical length of the polarized antenna. It is mainly determined by the length of the antenna itself. However, by increasing the arc-shaped branches on the outer edge of the radiator and the rectangular branches in the middle of the radiator surface, it will increase. The effect of the electrical length of the antenna, thereby changing the first resonance point of the polarized antenna; the second resonance point is a high-frequency resonance point, which is the resonance frequency obtained by combining the inductance and inductive capacitance of each pair of polarized antennas in the radiating unit. The rectangular branches on the radiator surface and the branches on the outer edge of the radiator act as inductance and capacitance, so the increased branches on the radiator make the present invention have a second resonance point; properly adjusting these two resonance frequencies can easily Get the required impedance matching bandwidth. Since the rectangular branches on the surface of the radiator and the branches on the outer edge of the radiator have very little influence on the radiation characteristics, the branches added on the radiator have almost no influence on the radiation characteristics of the dual-polarized antenna of the present invention.

(3) The first feeder and the second feeder in the radiating unit of the dual-polarized antenna of the present invention are orthogonal to each other, and there is a height difference between them, and the dual-polarized antenna can be improved by adjusting the height difference Isolation degree, the isolation degree of the dual-polarized antenna of the present invention can reach more than 40dB within the working frequency range of 1.71-2.69GH.

(5) The reflector of the dual-polarized antenna of the present invention is also provided with an inner flanging and an outer flanging. There is a current distribution on the antenna reflector, and the current distribution on the reflector can be changed by adding flanging on the reflection. And the flow direction of the current, adding flanging to the antenna array can improve its cross-polarization index very well. The radiation characteristics of the antenna can be further optimized by adjusting the height of the inner flanging and the outer flanging and the distance between them.

(6) The portion of the rectangular branches on the radiator of the radiation unit of the dual-polarized antenna of the present invention whose length exceeds the edges on both sides of the radiator can be bent vertically downwards, so that the size of the antenna can be reduced without changing the performance of the antenna. In addition, the rectangular branches on the radiator can be composed of several rectangular sections with different widths. Structures with different widths have different impedance characteristics. The combination of multiple widths can better adjust the impedance matching of the antenna.

Description of drawings

Fig. 1 is a support structure of a dual-polarized antenna radiating unit of the present invention.

Fig. 2 is the structure of the radiator of the dual-polarized antenna radiation unit of the present invention.

Fig. 3 is the structure of two feeding parts of the dual-polarized antenna radiation unit of the present invention.

Fig. 4 is a side view of the radiating unit of the dual-polarized antenna of the present invention.

Fig. 5 is a top view of the dual-polarized antenna array of the present invention.

Fig. 6 is a side view of the dual-polarized antenna array of the present invention.

Fig. 7 is a graph of the standing wave ratio of the dual-polarized antenna of the present invention.

Fig. 8 is a curve diagram of the isolation of the dual-polarized antenna of the present invention.

Fig. 9 is a gain diagram of the dual-polarized antenna of the present invention.

Figures 10a, 10b and 10c are the directivity diagrams of main polarization and cross polarization on the horizontal plane at the frequency of 1.7GHz, 2.2GHz and 2.7GHz, respectively, of the dual-polarized antenna port of the present invention.

Figures 11a, 11b and 11c are the directivity diagrams of main polarization and cross polarization on the horizontal plane at the frequency of 1.7GHz, 2.2GHz and 2.7GHz at port 2 of the dual-polarized antenna of the present invention.

detailed description

The present invention will be further described in detail below in conjunction with the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

Example

As shown in Figures 1 to 4, a wide-band high-isolation dual-polarization antenna radiating unit in this embodiment includes a reflector 4, a first feeder 5, a second feeder 6, a first radiator, a second Two radiators and four supporting parts, the four supporting parts are metal cylinders hollowed out in the middle and notched on the top. The four supports are respectively the first support 1a, the second support 1b, the third support 1c and the fourth support 1d, and the four supports are distributed on the four corners of the square, wherein the first support The positions of the part 1a and the third support part 1c are opposite, and the positions of the second support part 1b and the fourth support part 1d are opposite.

The first radiator is composed of two diagonal radiators 11 and 13, and the second radiator is composed of two diagonal radiators 12 and 14; the four radiators are respectively fixed on four supports, and the four supports The components are independently fixed on the reflection plate 4 by welding. The radiator 11 is fixed on the first support 1a, the radiator 12 is fixed on the second support 1b, the radiator 13 is fixed on the third support 1c, and the radiator 14 is fixed on the fourth support 1d.

The first feeding part 5 is the feeding structure of the first radiator, and the second feeding part 6 is the feeding structure of the second radiator, wherein both the first feeding part and the second feeding part are "Γ "type metal feeder; the top of the first feeder 5 passes through the first support 1a and is welded to the notch of the support 1c, and the top of the second feeder 6 passes through the support 1b and is welded to the support At the notch position of 1d; the tops of the first feeder 5 and the second feeder 6 are orthogonal to each other, and there is a height difference d. The first feeder 5 and the second feeder 6 are respectively connected to the middle probes of two SMA (SubMiniatureversionA, mini-type A connector) 5f and 6f connectors, and the outer conductors of the two SMAs are respectively connected to the reflector. The signal transmitted by the coaxial line feeds the metal feed through the SMA connector, and the feedback signal is transmitted from the bottom of the feeder to the radiation part on the top, and then radiated out by the radiation part.

A cross-shaped gap is formed in the middle of the four radiators, and rectangular branches 3a, 3b, 3c, and 3d that are longer than the radiator and face the outer edge of the radiator are arranged in the middle of the four radiators. The part whose length exceeds the radiator is bent vertically downward; the rectangular branches of the four radiators are orthogonal to each other; the structure, shape and size of the four radiators are all the same. The outer edge of each radiator is provided with arc-shaped branches 2a, 2b, 2c and 2d, and the four radiators form a circular structure. If the arc-shaped structure on the outer edge of each radiator is arranged as a rectangular branch, the four radiators in this embodiment form a square structure.

As shown in Figures 5 and 6, the present embodiment utilizes the above-mentioned multiple dual-polarized antenna radiating units to form a dual-polarized antenna array, and multiple dual-polarized radiating units are jointly fed by a power division network to form an antenna array. An inner flanging 7 and an outer flanging 8 are installed on the edge of the reflecting plate of the array.

As shown in Figure 7, it is the voltage standing wave ratio of the dual-polarized antenna radiating element of the present embodiment, wherein what the dotted line represents is the voltage standing wave ratio of the port one of the antenna, and what the solid line represents is the voltage standing wave of the port two of the antenna It can be seen from the figure that the antenna of this embodiment operates within the operating frequency range of 1.71-2.69 GHz, and the voltage standing wave ratio VSWR<1.5. In this embodiment, port 1 is connected to the first feeder and the first radiator, and port 2 is connected to the second feeder and the second radiator.

As shown in Figure 8, the isolation between port 1 and port 2 of the dual-polarized antenna radiating unit of this embodiment is shown. In the working frequency band range of 1.71-2.69GHz, the isolation of the antenna of this embodiment can almost reach 40dB .

As shown in Figure 9, the gain of port one of the dual-polarized antenna radiation unit of this embodiment is shown. As can be seen from Figure 8, the antenna of this embodiment is within the operating frequency band of 1.71-2.69GHz, and the gain is basically stable at 9 ± 0.7 in the dBi range.

Figures 10 and 11 are respectively the directivity diagrams of the horizontal plane main polarization and cross polarization of ports 1 and 2 of the dual-polarized antenna radiating unit at different frequencies. Within the GHz operating frequency range, the half-power beam lobe width is 65±4 degrees, and the cross-polarization at 0 degrees is above 38dB, so the mutual influence of the two polarized antennas on the antenna radiation unit is very small. The radiation pattern of the same polarized antenna is very stable, and its radiation direction basically remains unchanged at the frequency point of 1.7GHz-2.7GHz. It can be seen from Figures 10 and 11 that the antenna directions of port 1 and port 2 are basically the same at the same frequency, so they can be well combined to form a dual-polarized antenna.

In this embodiment, the dual-polarized antenna has two resonance points within the working frequency range of 1.71-2.69GH, and the first resonance point is a low-frequency resonance point, which refers to the resonance corresponding to the natural operating frequency of each dual-polarized antenna radiation unit. point, it is related to the electrical length of the antenna, which is mainly determined by the length of the antenna itself, but by increasing the arc-shaped branches on the outer edge of the radiator and the rectangular branches in the middle of the radiator surface, the electrical length of the antenna can be increased. Thereby changing the first resonance point of this polarized antenna. The second resonance point is the high-frequency resonance point, which is obtained by combining the inductance and inductive capacitance of each pair of polarized antennas in the radiation unit. The rectangular branches on the surface of the radiator and the branches on the outer edge of the radiator act as inductance and capacitance. When one pair of antennas in the radiation unit is fed, for example, the antenna composed of 1a, 2a, 3a and 1c, 2c, 3c is fed by the first feeding part 5, and the rest of the non-feeding parts 1b, 2b, 3b and 1d, 2d, 3d are equivalent to a capacitor loaded on the feeding antenna, while the branches 2a and 2c on the outer edges of the radiators 11 and 12 and the rectangular branches 3a and 3c on the surface are equivalent to an inductance, the loaded equivalent The combination of capacitance and inductance forms a new resonance frequency, which is the second resonance point. Properly adjusting these two resonant frequencies can easily obtain the required impedance matching bandwidth.

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, Simplifications should be equivalent replacement methods, and all are included in the protection scope of the present invention.

Claims (10)

1. A broadband high-isolation dual-polarized antenna radiation unit, comprising a reflector, a first feeder, a second feeder, a first radiator, a second radiator and four supports, the first Both the first radiator and the second radiator are composed of two diagonal radiators; the four radiators are respectively fixed on four supports, and the four supports are fixed on the reflector, characterized in that: The tops of the first feeding part and the second feeding part are orthogonal to each other, and there is a height difference, the first feeding part is the feeding structure of the first radiator, and the second feeding part is the second feeding part The feeding structure of the radiator, a cross-shaped gap is formed in the middle of the four radiators; the middle position of each radiator surface is provided with a rectangular branch that is longer than the radiator and faces the outer edge of the radiator. The outer edge of the radiator is provided with branches; the outer edge of the radiator refers to the side edge of the radiator away from the support, and the direction toward the outer edge of the radiator refers to the direction toward the outer edge of the radiator. 2. The wide-band high-isolation dual-polarized antenna radiating unit according to any one of claim 1, wherein the length of the rectangular branches exceeds the vertically downward bending of the part of the radiator; the four radiation The rectangular branches on the body surface are orthogonal to each other; the structure, shape and size of the four radiators are the same. 3. The wide-band high-isolation dual-polarized antenna radiating unit according to claim 1, characterized in that, the branches on the outer edge of the radiator are arc-shaped, and the four radiators form a circular structure. 4. The wide-band high-isolation dual-polarized antenna radiating unit according to claim 1, characterized in that, the branches on the outer edge of the radiator are rectangular, and the four radiators form a square structure. 5. The wide-band high-isolation dual-polarized antenna radiating unit according to claim 1, characterized in that, both the first feeder and the second feeder are "Γ"-shaped metal feeders. 6. The wide-band high-isolation dual-polarized antenna radiating unit according to claim 5, wherein the four support members are metal cylinders hollowed out in the middle; The four supports are respectively the first support, the second support, the third support and the fourth support, and the four supports are distributed on the four corners of the square, wherein the first support and The positions of the third support are relative, and the positions of the second support and the fourth support are relative; The top of the first feeder passes through the first support and is fixedly connected to the third support, and the top of the second feeder passes through the second support and is fixedly connected to the fourth support; The bottoms of the first feeder and the second feeder are respectively connected to the middle probes of the two SMA connectors, and the outer conductors of the two SMAs are connected to the reflector. 7. The wide-band high-isolation dual-polarized antenna radiating unit according to claim 5, characterized in that, there are gaps at the top of the four support members, and the top of the first feeding member passes through the first support member. It is connected to the notch of the third support by welding, and the top of the second feeder passes through the second support and is connected to the notch of the fourth support by welding. 8 . The wide-band high-isolation dual-polarized antenna radiating unit according to claim 1 , wherein the four support members are independently fixed on the reflector by welding. 9. A dual-polarized antenna based on the broadband high-isolation degree dual-polarized antenna radiating unit according to claim 1, characterized in that, at least 2 dual-polarized antenna radiating units are included, and a plurality of dual-polarized The radiating elements are jointly fed by a power dividing network to form an antenna array. 10 . The dual-polarized antenna according to claim 9 , wherein an inner flanging and an outer flanging are installed on the edge of the reflecting plate. 11 .