CN109994817A - An ultra-wideband dual-polarized base station antenna - Google Patents

Abstract

An ultra-wideband dual-polarized base station antenna, comprising a first dielectric substrate, an upper metal layer, a lower metal layer, a metal reflector, a coaxial line and a support column; the first dielectric substrate is supported on the metal reflector by at least four support columns On the top, the first dielectric substrate is directly fed by the coaxial line; the upper metal layer and the lower metal layer are printed on the upper and lower surfaces of the first dielectric substrate respectively; Cross-distributed dipole antennas; the two pairs of dipole antennas located on the upper metal layer correspond to the positions of the two pairs of dipole antennas located on the lower metal layer. The cross-distributed dipole antennas are all double-loop structures, and three modes are introduced to greatly expand the bandwidth, thereby realizing ultra-wideband characteristics; the cross-distributed dipole antennas are all double-loop structures, the outer ring is square, and the inner Ring, the introduction of three modes, greatly expand the bandwidth, so as to achieve ultra-wideband characteristics.

Description

An ultra-wideband dual-polarized base station antenna

technical field

The invention relates to the field of antenna engineering, in particular to an ultra-wideband dual-polarized base station antenna.

Background technique

With the rapid development of wireless communication technology, dual-polarized antennas have been widely used in wireless communication systems to alleviate signal multipath fading and improve channel capacity. In 2G/3G/4G base station applications, broadband (1.7-2.7 GHz) dual-polarized antennas with high isolation, high cross-polarization ratio, and stable half-power beamwidth (65±5°) are usually used to meet stringent requirements practical application requirements. With the emergence of new wireless systems such as fifth-generation (5G) wireless communication systems, research and design of ultra-wideband dual-polarized antennas covering 5G frequency bands (3.4-3.6GHz) and 2G/3G/4G frequency bands (1.7-2.7GHz) is imminent . Therefore, in order to reduce the installation volume of wireless communication equipment and reduce the processing cost, it has become a challenge for antenna researchers to design base station antennas with miniaturization, wide frequency band, high isolation, high cross-polarization ratio and stable radiation pattern. Base station antennas mainly have the following three forms: microstrip patch antennas, electromagnetic dipole antennas, and cross dipole antennas. The microstrip patch antenna has many shortcomings: the bandwidth is difficult to meet the 1.71-3.6GHz, the high cross-polarization ratio, and the in-band pattern varies greatly with frequency. Although the electromagnetic dipole antenna has excellent performance, it has a complex structure and a large volume. Crossed dipoles are currently widely used in wireless communication systems because of the following advantages: suitable operating bandwidth, stable radiation pattern, and easy planarization. However, with the increasing requirements of communication systems, ultra-wideband base station antennas with 2G/3G/4G/5G coverage are still a hot research topic.

B.Feng et al. published an article entitled "ABeamwidth Reconfigurable Antenna Array With Triple Dual-Polarized Magneto-Electric Dipole Elements" in IEEE Access (vol.6, pp.36083-36091, Jul. 2018), based on electromagnetic couple Pole has designed an antenna covering 1.7-3.6GHz. However, the antenna structure is not a plane structure, and the processing is more complicated. The radiation aperture is 65.9mm × 65.9mm, and the VSWR of the antenna is 2. "Multi-mode broadband antenna for 2G/3G/LTE/5G wireless communication" by R. Wu et al. in Electron. Lett. (vol. 54, no. 10, pp. 614-616, May 2018) A coupled-fed cross-dipole antenna with three modes is introduced in 1.7-3.6 GHz bandwidth with a VSWR of less than 2, however, the VSWR of this antenna is also greater than 1.5.

Y.Cui et al. published "Bandwidth Enhancement of a Broadband Dual-Polarized Antenna for 2G/3G/4G and IMT in IEEE Trans. Antennas Propag. (vol. 66, no. 12, pp. 7368-7373, Dec. 2018) Base Stations" article, the antenna adopts the method of slotting on the surface of the antenna and parasitic above the antenna to expand the antenna bandwidth to 67%. However, the antenna height is high, the antenna processing is complicated, and the antenna radiation pattern is in the frequency band of 1.7-2.7GHz The inner beamwidth is not stable. L.-H.Wen et al. published the article "A Wideband Dual-Polarized Antenna Using ShortedDipoles" in IEEE Access (vol.6, pp.39725-39733, Jul.2018), the antenna feed structure adopts coupled balun feed Electrical structure, feeding short-circuit dipoles, the antenna size is small, 49mm × 49mm, the antenna height is 35m, the antenna is easy to process, and the standing wave is less than 1.5. However, the antenna has a wider beam at high frequencies, and the gain decreases significantly. In the direction of radiation ±60°, the cross-polarization is relatively poor.

SUMMARY OF THE INVENTION

Aiming at the deficiencies of the prior art, the present invention proposes an ultra-wideband dual-polarized base station antenna, and the specific technical scheme is as follows: an ultra-wideband dual-polarized base station antenna, which is characterized in that it comprises a first dielectric substrate (1), an upper layer metal a layer (2), a lower metal layer (3), a metal reflector (4), a coaxial line (5) and a support column (6);

The first dielectric substrate (1) is supported on the metal reflector (4) by at least four support columns (6), and the first dielectric substrate (1) is directly fed by a coaxial line (5);

The upper metal layer (2) and the lower metal layer (3) are respectively printed on the upper surface and the lower surface of the first dielectric substrate (1);

Two dipole antennas that are distributed in a cross are printed on the upper metal layer (2) and the lower metal layer (3) respectively;

The two pairs of dipole antennas located in the upper metal layer (2) correspond to the positions of the two pairs of dipole antennas located in the lower metal layer (3);

The dipole antenna includes two mirror-symmetrical outer rectangular structures, and the first corners of the two outer rectangular structures are respectively connected together;

An inner rectangular structure is sleeved inside the outer rectangular structure, and the first corner of the inner rectangular structure is inserted into the first corner of the outer rectangular structure;

The two sides located at the first corner of the inner rectangular structure are immediately adjacent to the two sides located at the first corner of the outer rectangular structure.

In order to better realize the present invention, it can further be that: the interval between the two dipoles adopts an exponential curve gradient structure.

Further, the dipole antenna includes two mirror-symmetrical outer rectangular structures, the first corners of the two outer rectangular structures are respectively connected together, and a ring structure is sleeved inside the outer rectangular structures.

Further: the support column (6) is a nylon plastic column.

The beneficial effects of the present invention are as follows: first, the cross-distributed dipole antennas are all double-shaped ring structures, and three modes are introduced to greatly expand the bandwidth, thereby realizing ultra-wideband characteristics;

Second, the cross-distributed dipole antennas are all double-loop structures, the outer loop is square, and the inner loop is annular. Three modes are introduced to greatly expand the bandwidth, thereby achieving ultra-wideband characteristics;

Third, the spacing between the crossed dipoles adopts an exponential curve gradient structure, which greatly improves the matching of the antenna;

Fourth, the crossed dipole adopts double-layer metal, and two pairs of crossed dipoles are printed on the upper and lower metal layers of the dielectric plate, which has the effect of coupling feeding and greatly improves the matching.

Description of drawings

1 is a side view of an antenna in Embodiment 1 of the present invention;

Fig. 2 is the overall schematic diagram after each part in Fig. 1 is decomposed;

Fig. 3 is the top view schematic diagram of Fig. 1;

4 is a schematic diagram of the simulation and test results of the standing wave VSWR and isolation in Embodiment 1;

5 is a schematic diagram of simulation and test results of beamwidth and gain in Embodiment 1;

6 is the horizontal plane radiation directions of the four frequency points of 1.7GHz, 2.7GHz, 3.4GHz, and 3.6GHz in Embodiment 1;

7 is a side view of the antenna in Embodiment 2 of the present invention;

Fig. 8 is the top view schematic diagram of Fig. 7;

9 is a schematic diagram of the simulation and test results of the standing wave ratio VSWR and isolation in Embodiment 2;

10 is a schematic diagram of simulation and test results of beamwidth and gain in Embodiment 2;

FIG. 11 is a horizontal plane radiation pattern of three frequency points of 2.4 GHz, 3.5 GHz, and 5.5 GHz in Example 2. FIG.

Detailed ways

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, and the protection scope of the present invention can be more clearly defined.

As shown in Figure 1 to Figure 3, the specific structure in this embodiment 1:

A broadband miniaturized dual-polarized high isolation base station antenna, comprising a FR-4 dielectric substrate 1, an upper metal layer 2, a lower metal layer 3, a metal reflector 4, a coaxial line 5 and a nylon plastic column 6;

The FR-4 dielectric substrate 1 is supported on the metal reflector 4 by at least four nylon plastic columns 6, and the FR-4 dielectric substrate 1 is directly fed by the coaxial line 5;

The upper metal layer 2 and the lower metal layer 3 are respectively printed on the upper and lower layers of the FR-4 dielectric substrate 1. The upper metal layer 2 and the lower metal layer 3 are connected through 8 short-circuit pins 7, and the positive pole of the coaxial line is connected with the upper metal layer. The positive electrode of the antenna is fed through the transition metal strip 8 of the upper metal layer 2 , and the negative electrode of the coaxial line is connected to the lower metal layer 3 .

Two dipole antennas are printed on both the upper metal layer 2 and the lower metal layer 3 in a cross-distributed manner.

The parameters used in Example 1 are that the crossed dipoles of the upper metal layer 2 and the lower metal layer 3 have the same size, the total side length is 49 mm, and two pairs of crossed dipoles are printed on the upper and lower metal layers. The spacing between the poles gradually increases from the center to the edge, and the curve is exponential. The FR-4 dielectric substrate 1 has a thickness of 1 mm and a dielectric constant of 4.4. The distance from the antenna to the metal reflector 4 is 35mm. The size of the metal reflector 4 is 145 mm×145 mm. The coaxial line 5 is a standard coaxial line with an inner diameter of 0.52mm.

FIG. 4 is a schematic diagram of simulation and test results of standing wave VSWR and isolation of the invented broadband miniaturized dual-polarized high isolation antenna. In the frequency range of 1.7-3.7GHz, the standing wave VSWR of the antenna is less than 1.5, and the isolation is greater than 28dB. The simulation results are in good agreement with the test results.

FIG. 5 is a schematic diagram of simulation and test results of the horizontal plane beam width and antenna gain of the invented broadband miniaturized dual-polarized high isolation antenna. In the frequency range of 1.7-2.7GHz, the beam width of the radiation pattern of the antenna in the horizontal plane is about 65°, and the gain of the antenna is about 8.5dBi. The simulation results are in good agreement with the test results.

Fig. 6 is the radiation pattern of the invented broadband miniaturized dual-polarization high isolation antenna at four frequency points of 1.7GHz, 2.7GHz, 3.4GHz and 3.6GHz on the horizontal plane, the main polarization and cross-pole of the four frequency points The conversion ratio is greater than 23dB, the radiation pattern is stable, and the simulation results are in good agreement with the test results.

As shown in Figure 7 to Figure 8, the specific structure in this embodiment 2:

The difference between the second embodiment and the first embodiment is that the dipole antenna includes two outer rectangular structures that are mirror-symmetrical, and the first corners of the two outer rectangular structures are respectively connected together. An annular structure is sleeved inside the outer rectangular structure.

The parameters of this embodiment 2 are that the crossed dipoles of the upper metal layer 2 and the lower metal layer 3 have the same size, the total side length is 35.2 mm, and two pairs of crossed dipoles are printed on the upper and lower metal layers. The spacing between the poles gradually increases from the center to the edge, and the curve is exponential. Rogers-4350 dielectric substrate 1 has a thickness of 1 mm and a dielectric constant of 3.66. The distance from the antenna to the metal reflector 4 is 19.5 mm. The size of the metal reflector 4 is 80 mm×80 mm. The coaxial line 5 is a standard coaxial line with an inner diameter of 0.52mm.

FIG. 9 is a schematic diagram of the simulation and test results of the standing wave ratio VSWR and isolation of the invented broadband miniaturized dual-polarized high isolation antenna. In the frequency range of 2.4-6.4GHz, the standing wave ratio VSWR of the antenna is less than 2, the relative bandwidth reaches 92%, and the isolation is greater than 28dB. The simulation results are in good agreement with the test results.

FIG. 10 is a schematic diagram showing the simulation and test results of the horizontal plane beam width and antenna gain of the invented broadband miniaturized dual-polarized high isolation antenna. In the frequency range of 2.4-5.85GHz, the beam width of the radiation pattern of the antenna on the horizontal plane is about 65°, the gain of the antenna is about 8.5dBi in the low frequency band, and the high frequency band decreases. The simulation results are consistent with the test results. very good.

Fig. 11 is the radiation pattern of the invented broadband miniaturized dual-polarization high isolation antenna at 2.4GHz, 3.5GHz, 5.5GHz, the horizontal plane of three frequency points, the main polarization and cross-polarization ratio of the three frequency points Greater than 23dB, the radiation pattern is stable, and the simulation results are in good agreement with the test results.

Claims (4)

1. a kind of ultra wideband dual polarization antenna for base station, it is characterised in that: including first medium substrate (1), upper metal layers (2), Lower metal layer (3), metallic reflection plate (4), coaxial line (5) and support column (6)；

The first medium substrate (1) is supported on the metallic reflection plate (4) by least four support columns (6), and described first Medium substrate (1) is by coaxial line (5) direct feed；

The upper metal layers (2) and the lower metal layer (3) are respectively printed at the upper surface of the first medium substrate (1) The lower surface and；

Print two dipole days in cross-distribution respectively in the upper metal layers (2) and the lower metal layer (3) Line；

The two electrode couple sub-antennas positioned at the upper metal layers (2) and two electrode couples positioned at the lower metal layer (3) Aerial position is corresponding；

The dipole antenna include two be in mirror symmetry outer rectangular configuration, the first jiao point of two outer rectangular configurations It does not link together；

Interior rectangular configuration, first jiao of insertion outer rectangle of the interior rectangular configuration are equipped in the outer rectangular configuration internal sleeve In first jiao of structure；

The both sides of first jiao of the outer rectangular configuration are immediately adjacent to positioned at the both sides of first jiao of the interior rectangular configuration.

2. a kind of ultra wideband dual polarization antenna for base station according to claim 1, it is characterised in that: between two dipoles Away from using exponential curve grading structure.

3. a kind of ultra wideband dual polarization antenna for base station according to claim 1, it is characterised in that: the dipole antenna includes Two outer rectangular configurations in mirror symmetry, first jiao of two outer rectangular configurations are respectively connected together, described outer Rectangular configuration internal sleeve is equipped with ring structure.

4. a kind of ultra wideband dual polarization antenna for base station according to claim 1, it is characterised in that: the support column (6) is Buddhist nun Imperial plastic column.