Split sector multi-band antenna with hybrid tilt mechanism
By employing a split-sector design with tilted and planar reflectors in cellular antennas, combined with mechanical and electrical tilting mechanisms, the problems of wind load and beam quality degradation are solved, achieving high-quality beamforming and reduced wind load.
Patent Information
- Application Number
- CN202480013568.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-02-10
- Filing Date
- 2024-02-09
- Publication Date
- 2025-10-03
AI Technical Summary
Existing cellular antennas, when providing high-quality beamforming in multiple directions, have conventional solutions that increase the volume and area of the radome, leading to wind load issues and degraded beam quality.
Employing a split-sector antenna design with tilted and planar reflectors, combined with mechanical and electrical tilting mechanisms, and by setting up dipole arrays in different frequency bands, it provides high-quality beams and reduces wind load.
It achieves high-quality beamforming in multiple directions while reducing wind load on the radome, maintaining beam gain and reducing sidelobe levels.
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Figure CN120752811A_ABST
Abstract
Description
Background Art
[0001] Modern cellular communications require the deployment of antennas that support multiple frequency bands: one or more higher frequency bands for higher bandwidth and data rates, and one or more lower frequency bands for robust coverage within a structure and at greater coverage distances. Furthermore, there is an increasing demand for antenna sectorization, which increases the capacity of an antenna by dividing its coverage area into multiple sectors. Antenna sectorization requires the antenna to be able to provide beams that can be pointed in different directions in the azimuth plane.
[0002] In addition to the aforementioned performance requirements, cellular antennas (especially macro antennas) have stringent requirements for wind loading. Macro cellular antennas must have a minimal cross-sectional profile to minimize wind loading when mounted atop a cellular tower. This imposes constraints on the size and design of the antenna's radome.
[0003] Conventional solutions for providing sectorization can involve refractive lenses or Butler matrices to apply amplitude and phase differences for beamforming. These conventional solutions have drawbacks: first, reflective lenses increase the volume and area of the radome, exacerbating wind loading issues; and, in conventional beamforming, beam quality degrades and increases steering angles due to reduced gain and worsening sidelobes.
[0004] Therefore, there is a need for a cellular antenna that can provide a high-quality beam profile in multiple directions while minimizing wind loading. Summary of the Invention
[0005] One aspect of the present disclosure relates to an antenna. The antenna includes a first tilted portion, the first tilted portion having a first tilted reflector and a first planar reflector, the first tilted reflector having a first plurality of dipoles configured to radiate in a first frequency band, the first planar reflector having a second plurality of dipoles configured to radiate in a second frequency band having a higher frequency than the first frequency band, the first tilted reflector being tilted at a first tilt angle; and a second tilted portion having a second tilted reflector and a second planar reflector, the second tilted reflector having a third plurality of dipoles configured to radiate in the first frequency band, the second planar reflector having a fourth plurality of dipoles configured to radiate in the second frequency band, the second tilted reflector being tilted at a second tilt angle. BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Figure 1A An exemplary split-sector antenna according to the present disclosure is shown.
[0007] Figure 1B yes Figure 1AAnother view of an exemplary split-sector antenna.
[0008] Figure 1C yes Figure 1A A top view of an exemplary split-sector antenna.
[0009] Figure 2A An end view of the internal structure of an exemplary split-sector antenna according to the present disclosure is shown.
[0010] Figure 2B Shown Figure 2A The internal structure of the 1930s is different from the original, but it is equipped with a conformal radome.
[0011] Figure 3A A top view of an exemplary conformal radome according to the present disclosure is provided.
[0012] Figure 3B A side view of an exemplary conformal radome according to the present disclosure is provided.
[0013] Figure 3C Cross-sectional profiles of first and second housing portions of exemplary conformal radomes of the present disclosure are provided.
[0014] Figure 4A is a cross-sectional view of a tilted reflector and a planar reflector of an embodiment of the present disclosure having a split sector antenna with 27 degrees of mechanical tilt.
[0015] Figure 4B is a cross-sectional view of a tilted reflector and a planar reflector of a split sector antenna of the present disclosure having 22 degrees of mechanical tilt and 5 degrees of electrical tilt.
[0016] Figure 4C is a cross-sectional view of a tilted reflector and a planar reflector of a split sector antenna of the present disclosure having 17 degrees of mechanical tilt and 10 degrees of electrical tilt. DETAILED DESCRIPTION
[0017] Figure 1AAn exemplary split sector antenna 100 according to the present disclosure is shown. The exemplary split sector antenna 100 has dipoles that radiate in two different frequency bands: low band (LB) (617-860 MHz) and mid band (MB) (1695-2690 MHz). The split sector antenna 100 has a first tilted portion 105 and a second tilted portion 110. The first tilted portion 105 has a first tilted reflector 115 and a first planar reflector 125, with an array of LB dipoles 135 disposed on the first tilted reflector 115 and an array of MB dipoles 140 disposed on the first planar reflector 125. The second tilted portion 110 has a second tilted reflector 120 and a second planar reflector 130, with an array of LB dipoles 135 disposed on the second tilted reflector 120 and an array of MB dipoles 140 disposed on the second planar reflector 130. The first tilted reflector 115 and the second tilted reflector 120 may have the same but opposite tilt angles. Figure 1A , wherein the x-axis corresponds to the vertical axis and the azimuth plane is defined by the y-axis and the z-axis. As shown, the tilt angles of the first tilted reflector 115 and the second tilted reflector 120 are about the x-axis. The exemplary split sector antenna 100 may have a conformal radome 150.
[0018] Figure 1B is a rotated view of the split-sector antenna 100.
[0019] Figure 1C FIG. 1 is a top view of the split sector antenna 100 along the negative direction of the z-axis.
[0020] Figure 2A An end view of the internal structure of the split-sector antenna 100 is shown, with the conformal radome 150 removed. This view is along the x-axis. A first tilted reflector 115 is shown, on which an LB dipole array 135 is disposed. The first tilted reflector 115 can be mechanically coupled to a first planar reflector 125, on which an MB dipole array 140 is disposed. A second tilted reflector 120 is shown, on which an LB dipole array 135 is disposed. The second tilted reflector 120 can be mechanically coupled to a second planar reflector 130, on which an MB dipole array 140 is disposed.
[0021] Figure 2B Shown Figure 2A structure, but equipped with a conformal radome 150.
[0022] Figure 3A1 is a top view of an exemplary conformal radome 150 along the negative z-axis. The conformal radome 150 has a first shell portion 305 covering the first angled portion 105, a second shell portion 310 covering the second angled portion 110, and a transition section 315 providing a transition profile between the first shell portion 305 and the second shell portion 310.
[0023] Figure 3B is a side view of exemplary conformal radome 150 along the negative y-axis, illustrating first housing portion 305 , second housing portion 310 , and transition section 315 .
[0024] Figure 3C 30. Example cross-sectional profiles of a first housing portion 305 and a second housing portion 310 are shown. The first housing portion 305 can have an inclined shape, wherein the inclined shape has an inclination angle 307, which can be substantially similar to the inclination angle of the first inclined reflector 115. Similarly, the second housing portion 310 can have an inclined shape with an inclination angle 312 that can be substantially similar to the inclination angle of the second inclined reflector 120. As used herein, an inclined shape having an inclination angle 307 / 312 that is substantially similar to the inclination angle of the corresponding reflector can mean that the inclined shape can have a curvature (rather than a flat surface), and the inclination angle 307 / 312 can approximate the angle formed by the inclined shape.
[0025] The shape of the conformal radome 150 may provide benefits in reducing wind loads due to the angled surfaces of the first shell portion 305 and the second shell portion 310 .
[0026] The tilt angles of the first and second tilted reflectors 115, 120 provide an angular bias for directing the beams formed by the respective arrays of LB dipoles 135 formed on the first and second tilted reflectors 115, 120. For each of the first and second tilted reflectors 115, 120, the optimal gain corresponds to a beam formed orthogonally to the respective reflector surface. In an exemplary embodiment according to the present disclosure, the tilt angles of the first and second tilted reflectors 115, 120 can be such that the mechanical tilt is sufficient to provide two distinct beams for two separate sectors. For example, if the tilt angle of the first tilted reflector 115 is +27 degrees and the tilt angle of the second tilted reflector 120 is -27 degrees, the gain patterns of the first and second tilted reflectors 115, 120 are spaced 54 degrees apart. That is, the direction perpendicular to the first and second tilted reflectors are 54 degrees apart in the azimuth plane. This may be sufficient separation. However, setting the tilt angle to + / - 27 degrees increases the height of the antenna 100 and the conformal radome 150 in the z-direction. If there is a limit on the height of the conformal radome 150 along the z-axis, the antenna 100 can be configured to have a reduced tilt angle, thereby reducing the height of the conformal radome 150. However, the reduced tilt angle correspondingly reduces the azimuth plane angular separation of the beams (gain patterns) emitted by the first tilted reflector 115 and the second tilted reflector 120. In this case, in order to maintain the angular separation in the azimuth plane, it is necessary to apply electrical beam tilt to move the respective beams away from each other. This maintains the azimuth plane angular separation while reducing the height of the conformal radome 150. As used herein, a hybrid tilt mechanism is a combination of mechanical tilt (the tilt angle of the first tilted reflector 115 and the second tilted reflector 120) and an electrical tilt mechanism.
[0027] Having a set tilt angle substantially mitigates the beam quality degradation caused by the electrical tilt method. According to the electrical tilt method, providing differential amplitude and phase weighting to the signals fed to the LB dipoles 135 steers the beam emitted by the corresponding array of LB dipoles 135 in the azimuth plane (defined by the z-axis and the y-axis). As the beam is steered, the antenna gain decreases proportionally with the angle according to the cos(θ) relationship, where θ is the beam steering angle from the direction perpendicular to the reflector surface. Accordingly, as the angle increases, beam performance degrades—not only does the gain decrease, but the sidelobe level also increases.
[0028] Figure 4AA cross-sectional view of the second tilted reflector 120 and second planar reflector 130 of an embodiment of the disclosed split-sector antenna with 27-degree mechanical tilt, along with exemplary dimensions, is shown. In this example, the first tilted reflector 115 and the first planar reflector 125 may have the same but opposite tilts. To simplify the drawing, they have been omitted from the figure. As shown, the second tilted reflector 120 has an array of LB dipoles 135 disposed thereon, and the second planar reflector 130 may have an array of MB dipoles 140 disposed thereon. In this example, the two LB beams are thus offset 27 degrees from the normal (z-axis), providing a 54-degree spread in the azimuth plane (defined by the x- and y-axes). In this exemplary embodiment, no electrical tilt is required to maintain beam separation. Given the + / - 27-degree tilt angles of the first tilted reflector 115 and the second tilted reflector 120, the conformal radome 150 would need to extend 12 inches along the z-axis.
[0029] In the disclosed exemplary embodiment, the array of LB dipoles 135 on the first and second tilted reflectors 115, 120 may provide a beamwidth of 33 degrees. However, it should be understood that variations in this beamwidth are possible and within the scope of the present disclosure.
[0030] Figure 4B 1 is a cross-sectional view of the second tilted reflector 120 and the second planar reflector 130 of an embodiment of the disclosed split-sector antenna having a 22-degree mechanical tilt, along with exemplary dimensions. As with the previous example, the first tilted reflector 115 and the first planar reflector 125 may have the same but opposite tilts. To simplify the drawing, they have been omitted from the drawing. However, the direction perpendicular to the first tilted reflector and the direction perpendicular to the second tilted reflector are angularly separated by 44 degrees in the azimuth plane. As shown, the second tilted reflector 120 has an array of LB dipoles 135 disposed thereon, and the second planar reflector 130 may have an array of MB dipoles 140 disposed thereon. In this exemplary embodiment, in order to maintain a + / - 27-degree beam separation in the azimuth plane, it is necessary to apply electronic beam steering (via differential phase and amplitude weighting) to steer the beam an additional 5 degrees to a 22-degree tilt angle. In this case, the array of LB dipoles 135 disposed on the first tilted reflector 115 would have additional phase shifter circuitry (not shown) to impart an additional +5 degrees of electrical tilt above the existing +22 degrees of tilt. Similarly, the array of LB dipoles 135 disposed on the second tilted reflector 120 would have additional phase shifter circuitry (not shown) to impart an additional -5 degrees of electrical tilt above the existing -22 degrees of tilt. An advantage of this exemplary embodiment is that the height of the conformal radome 150 along the z-axis is 10.5 inches.
[0031] Figure 4CA cross-sectional view of the second tilted reflector 120 and second planar reflector 130, along with exemplary dimensions, of an embodiment of the disclosed split-sector antenna with 17 degrees of mechanical tilt is shown. The LB array uses a fractional array factor to provide 10 degrees of electrical tilt, thereby creating a ±27-degree split-sector antenna. As with the other two examples, the first tilted reflector 115 and the first planar reflector 125 may have identical but opposite tilts. To simplify the drawing, they have been omitted. However, the direction perpendicular to the first tilted reflector and the direction perpendicular to the second tilted reflector are angularly separated by 34 degrees in the azimuth plane. As shown, the second tilted reflector 120 has an array of LB dipoles 135 disposed thereon, and the second planar reflector 130 may have an array of MB dipoles 140 disposed thereon. In this exemplary embodiment, to maintain a + / - 27-degree beam separation in the azimuth plane, electronic beam steering (via differential phase and amplitude weighting) is necessary to steer the beam to an additional tilt angle of 10 to 17 degrees. In this case, the array of LB dipoles 135 disposed on the first tilted reflector 115 would have additional phase shifter circuitry (not shown) to impart an additional +10 degrees of electrical tilt above the existing +17 degrees of tilt. Similarly, the array of LB dipoles 135 disposed on the second tilted reflector 120 would have additional phase shifter circuitry (not shown) to impart an additional -10 degrees of electrical tilt above the existing -17 degrees of tilt. An advantage of this exemplary embodiment is that the height of the conformal radome 150 along the z-axis is 9 inches.
[0032] Variations of the split sector antenna 100 are possible. For example, dipoles for different frequency bands can be used: the LB dipole 135 and the MB dipole 140 can be reversed, such that the MB dipole 140 is disposed on the first tilted radiator 115 and the second tilted radiator 120. Furthermore, additional dipoles and dipole arrays are possible, such as those operating in the C-band. Furthermore, while a desired beam separation of 54 degrees is discussed above, it should be understood that other beam separations and resulting tilt angles can be used. It should be understood that such variations are possible and within the scope of the present disclosure.
Claims
1. An antenna, comprising: The first inclined portion has a first inclined reflector and a first flat reflector. A first plurality of dipoles configured to radiate in a first frequency band is disposed on the first tilted reflector, a second plurality of dipoles configured to radiate in a second frequency band is disposed on the first planar reflector, the second frequency band having a higher frequency than the first frequency band, and the first tilted reflector is tilted at a first tilt angle relative to the first planar reflector; as well as a second tilted portion, the second tilted portion having a second tilted reflector and a second planar reflector, a third plurality of dipoles disposed on the second tilted reflector, the third plurality of dipoles being configured to radiate in the first frequency band, a fourth plurality of dipoles disposed on the second planar reflector, the fourth plurality of dipoles being configured to radiate in the second frequency band, the second tilted reflector being tilted at a second tilt angle relative to the second planar reflector, The first planar reflector and the second planar reflector are oriented in the same direction in an azimuthal plane. 2 . The antenna according to claim 1 , wherein the second tilt angle is an opposite angle of the first tilt angle in the azimuth plane. The antenna of claim 1 , further comprising a conformal radome.
4. The antenna of claim 3, wherein the conformal radome comprises: a first housing portion configured to cover the first inclined portion; a second housing portion configured to cover the second inclined portion; as well as A transition section is provided between the first shell portion and the second shell portion. 5 . The antenna of claim 4 , wherein the first housing portion comprises a slope shape having a first slope angle, the first slope angle being substantially equal to the first tilt angle. 6 . The antenna according to claim 5 , wherein the second housing portion comprises a slope shape having a second slope angle, the second slope angle being substantially equal to the second inclination angle. The antenna of claim 1 , wherein the first frequency band comprises a low frequency band. The antenna of claim 7 , wherein the second frequency band comprises a mid-frequency band.
9. The antenna of claim 1, wherein the first tilted reflector is mechanically coupled to the first planar reflector, and wherein the second tilted reflector is mechanically coupled to the second planar reflector.
10. The antenna of claim 2, wherein the first tilt angle is 27 degrees and the second tilt angle is -27 degrees, so that there is a difference of 54 degrees between a direction perpendicular to the first tilt reflector and a direction perpendicular to the second tilt reflector.
11. The antenna of claim 2, wherein the first tilt angle is +22 degrees and the second tilt angle is -22 degrees, so that there is a 44 degree difference between a direction perpendicular to the first tilt reflector and a direction perpendicular to the second tilt reflector.
12. The antenna according to claim 11, further comprising: a first electrical tilt circuit coupled to the first plurality of dipoles, the first electrical tilt circuit configured to control the pointing of a first antenna beam generated by the first plurality of dipoles so as to impart an additional +5 degrees of tilt angle to the first antenna beam; as well as A second electrical tilt circuit is coupled to the third plurality of dipoles, the second electrical tilt circuit being configured to control the pointing of a second antenna beam generated by the second plurality of dipoles to impart an additional tilt angle of -5 degrees to the second antenna beam.
13. The antenna of claim 12, wherein the conformal radome has a height of 10.5 inches.
14. The antenna of claim 2, wherein the first tilt angle is +17 degrees and the second tilt angle is -17 degrees, so that there is a 34 degree difference between a direction perpendicular to the first tilt reflector and a direction perpendicular to the second tilt reflector.
15. The antenna according to claim 14, further comprising: a first electrical tilt circuit coupled to the first plurality of dipoles, the first electrical tilt circuit configured to control the pointing of a first antenna beam generated by the first plurality of dipoles so as to impart an additional +10 degrees tilt angle to the first antenna beam; as well as A second electrical tilt circuit is coupled to the third plurality of dipoles, the second electrical tilt circuit being configured to control the pointing of a second antenna beam generated by the second plurality of dipoles so as to impart an additional tilt angle of -10 degrees to the second antenna beam.
16. The antenna of claim 15, wherein the conformal radome has a height of 9 inches.
17. An antenna comprising: a first portion having a first reflector and a second reflector, the first reflector having a first plurality of dipoles disposed thereon, the first plurality of dipoles being configured to radiate in a first frequency band, the second reflector having a second plurality of dipoles disposed thereon, the second plurality of dipoles being configured to radiate in a second frequency band having a frequency higher than that of the first frequency band; as well as a second portion having a first reflector and a second reflector, the first reflector being provided with a third plurality of dipoles configured to radiate in the first frequency band, the second reflector being provided with a fourth plurality of dipoles configured to radiate in the second frequency band, wherein the first reflector and the second reflector of the first portion have an orientation such that a direction of the first reflector perpendicular to the first portion and a direction of the second reflector perpendicular to the first portion are separated by a first tilt angle in an azimuthal plane, wherein the first reflector and the second reflector of the second portion have an orientation such that a direction perpendicular to the first reflector of the second portion and a direction perpendicular to the second reflector of the second portion are separated in an azimuthal plane by a second tilt angle opposite to the first tilt angle, and A direction of the second reflector perpendicular to the first portion and a direction of the second reflector perpendicular to the second portion are the same direction.
18. The antenna according to claim 17, wherein the first reflector and the second reflector of the first portion are mechanically coupled to each other, and wherein the first reflector and the second reflector of the second portion are mechanically coupled to each other.
19. The antenna according to claim 17, further comprising: a first electrical tilt circuit coupled to the first plurality of dipoles, the first electrical tilt circuit configured to control the pointing of a first antenna beam generated by the first plurality of dipoles so as to impart a first additional tilt angle to the first antenna beam; as well as A second electrical tilt circuit is coupled to the third plurality of dipoles, the second electrical tilt circuit being configured to control the pointing of a second antenna beam generated by the second plurality of dipoles to impart a second additional tilt angle to the second antenna beam.
20. The antenna of claim 17, further comprising a conformal radome, wherein the conformal radome comprises: a first housing portion configured to cover the first portion, a second housing portion configured to cover the second portion, and A transition section is provided between the first housing portion and the second housing portion, and The first housing portion includes a slope shape having a first slope angle depending on the first inclination angle, and the second housing portion includes a slope shape having a second slope angle depending on the second inclination angle.