Shaped antenna reflectors and reflector antennas

Abstract

This invention relates to the field of wireless communication technology, and provides a shaped antenna reflector and a reflector antenna, having a shaped reflector surface, including a parabolic reflector surface that is at least a portion of a semi-parabolic rotator and a swept reflector surface that is at least a portion of a swept surface; the generatrix of the semi-parabolic rotator is a parabolic segment whose vertex is on the parabola, and the semi-parabolic rotator is formed by rotating the generatrix by 180° about the axis of symmetry of the parabola; the edge of the parabolic reflector has a connecting edge that is located on the same parabola as the generatrix, and the swept surface is formed by sweeping the connecting edge in a direction away from the parabolic reflector surface, and the swept reflector surface is tangent to the parabolic reflector surface at the connecting edge; the shaped reflector surface is used to reflect spherical waves emitted from the feed on the concave side of the parabolic reflector surface, the reflected beam is a deformed cosecant square beam in a first plane direction and a narrow beam in a second plane direction, the first plane direction is consistent with the direction of the central symmetry plane of the semi-parabolic rotator, and the first plane direction and the second plane direction are perpendicular.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to a shaped antenna reflector and a reflector antenna. Background Technology

[0002] With the rapid development of transportation, achieving efficient network coverage in narrow environments such as railways, roads, and bridges has become a major challenge. Traditional base station antennas have a half-power beamwidth of 65°, requiring multiple antennas to form an array to cover the entire narrow area. This results in frequent signal switching, affecting communication quality. Therefore, taking railways as an example, narrow-beam, high-gain antennas are currently commonly used for coverage. For safety reasons, the communication towers where the antennas are installed must have sufficient distance from the tracks to avoid the risk of encroachment. However, this creates a horizontal null point phenomenon, forming coverage blind spots and degrading communication quality. Figure 1 As shown, in existing antenna technology, the beams of the horizontal main beam that are close to the railway track are effective beams and contribute to network coverage, while the beams that are off the railway track are ineffective beams and do not contribute to network coverage, thus reducing the coverage effect of the antenna. Summary of the Invention

[0003] This invention provides a shaped antenna reflector and a reflector antenna to solve the problems of horizontal coverage blind spots and low antenna gain caused by excessively large invalid main beams in the application of antennas in narrow environments in the prior art.

[0004] The present invention provides a shaped antenna reflector having a shaped reflecting surface, the shaped reflecting surface including a parabolic reflecting surface and a swept reflecting surface;

[0005] The parabolic reflector is at least a part of a semi-parabolic surface of revolution, and the swept reflector is at least a part of a swept surface; the generatrix of the semi-parabolic surface of revolution is a parabolic segment, one end of the parabolic segment is the vertex of the parabola it is on, and the semi-parabolic surface of revolution is formed by rotating the generatrix about the axis of symmetry of the parabola by 180°.

[0006] The parabolic reflective surface has a connecting edge, and the connecting edge and the generatrix of the semi-parabolic surface are located on the same parabola. The swept surface is formed by sweeping the connecting edge in a direction away from the parabolic reflective surface, and the swept reflective surface is tangent to the parabolic reflective surface at the connecting edge.

[0007] The shaped reflector is used to reflect spherical waves emitted from a feed located on the concave side of the parabolic reflector. The reflected beam is a deformed cosecant square beam in the first plane direction and a narrow beam in the second plane direction. The first plane direction is consistent with the direction of the central symmetry plane of the semi-parabolic surface, and the first plane direction and the second plane direction are perpendicular.

[0008] According to the shaped antenna reflector provided by the present invention, in a rectangular coordinate system formed by the orthogonal X-axis, Y-axis and Z-axis, the vertex coincides with the origin O of the rectangular coordinate system, the connecting edge is on the XOZ plane, and the axis of symmetry is the Z-axis; the first plane direction is the direction of the YOZ plane, the second plane direction is the direction of the XOZ plane, and the swept surface is formed by the connecting edge sweeping along the YOZ plane.

[0009] According to a shaped antenna reflector provided by the present invention, the swept surface is formed by sweeping a straight line along the connecting edge, the straight line being coincident with the Y-axis, or the straight line extending obliquely away from the concave side relative to the Y-axis.

[0010] Alternatively, the swept surface is formed by sweeping the connecting edge along a curve on the YOZ plane.

[0011] According to the present invention, a shaped antenna reflector is provided, wherein the parabolic reflector is part of a semi-parabolic surface of revolution and is located on one side of the YOZ plane;

[0012] And / or, the corner of the swept reflective surface away from the parabolic reflective surface is chamfered or rounded.

[0013] According to the present invention, a shaped antenna reflector is provided, wherein the shaped antenna reflector is an integral structure or a split structure;

[0014] And / or, the shaped antenna reflector is a plate-shaped solid structure, a plate-shaped hollow structure, or a mesh structure;

[0015] And / or, the shaped antenna reflector is made of aluminum alloy, zinc alloy, steel, or has a metal coating.

[0016] According to the shaped antenna reflector provided by the present invention, the gap width of the plate-shaped hollow structure and the mesh structure is less than λ / 10, where λ is the operating frequency wavelength of the antenna.

[0017] The present invention also provides a reflector antenna, comprising: a feed source and any of the above-described shaped antenna reflectors;

[0018] The feed source is located on the concave side of the parabolic reflector and points towards the shaped reflector, and the radiation phase center of the feed source is located at the focal point of the parabolic reflector.

[0019] The present invention also provides a reflector antenna, comprising: a feed source, a sub-reflector, and any of the above-described shaped antenna reflectors, wherein the feed source and the sub-reflector are both located on the concave side of the parabolic reflector;

[0020] The sub-reflector has a sub-reflecting surface, which is part of an ellipsoid with its concave side facing the shaped reflecting surface. The sub-reflecting surface has a first focal point and a second focal point, with the second focal point being closer to the sub-reflecting surface than the first focal point. The second focal point coincides with the focal point of the parabolic reflecting surface.

[0021] The feed source is directed to the second focal point, and its radiation phase center is located at the first focal point.

[0022] The present invention also provides a reflector antenna, comprising: a feed source, a sub-reflector, and any of the above-mentioned shaped antenna reflectors, wherein the feed source and the sub-reflector are both located on the concave side of the parabolic reflector;

[0023] The sub-reflector has a sub-reflecting surface, which is at least a portion of one branch of a double-leaf hyperboloid and its convex side faces the shaped reflecting surface. The virtual focal point of the sub-reflecting surface coincides with the focal point of the parabolic reflecting surface.

[0024] The feed point is directed to the virtual focus of the sub-reflector, and its radiation phase center is located at the virtual focus of the other branch of the double-leaf hyperboloid.

[0025] According to the present invention, a reflector antenna is provided, wherein the parabolic reflector is part of a semi-parabolic rotational surface and is located on one side of the YOZ plane, and the feed source is offset on the XOZ plane with the focus of the parabolic reflector as the center and to the other side of the YOZ plane.

[0026] The shaped antenna reflector and reflector antenna provided by this invention include a tangent parabolic reflector and a swept reflector. The parabolic reflector is at least a portion of a semi-parabolic spheroid, and the swept reflector is a portion of the swept reflector. The generatrix of the semi-parabolic spheroid is a parabolic segment, and one end of the parabolic segment is the vertex of the parabola it lies on. The semi-parabolic spheroid is formed by rotating its generatrix by 180° around the axis of symmetry of the parabola. The parabolic reflector has a connecting edge on the same parabola as the generatrix of the semi-parabolic spheroid. The swept reflector is formed by sweeping the connecting edge in a direction away from the parabolic reflector. This shaped antenna reflector can cooperate with a feed source so that the spherical wave emitted from the feed source is reflected by the shaped reflector, and the reflected wave forms a deformed cosecant square beam in the first plane direction (corresponding to the horizontal direction) and a narrow beam in the second plane direction (corresponding to the vertical direction). The deformed cosecant square beam has an asymmetric structure, resulting in a greater energy distribution in the target-side beam (effective beam), which improves the antenna gain and increases the longitudinal coverage range. Meanwhile, the horizontal beam eliminates horizontal nulls over a large area, avoiding coverage blind spots. Furthermore, compared to conventional techniques that use shaped array antennas to achieve deformed cosecant square beams, this method is simpler in structure, lower in cost, and easier to manufacture. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the coverage of a railway on a horizontal plane using a current narrow-beam high-gain antenna.

[0029] Figure 2 This is a schematic diagram of the coverage of a railway on a vertical plane using a current narrow-beam high-gain antenna.

[0030] Figure 3 This is a three-dimensional structural schematic diagram of one of the reflector antennas provided by the present invention.

[0031] Figure 4 yes Figure 3 A schematic diagram of the shaped antenna reflector structure.

[0032] Figure 5 This is a schematic diagram of the shaped antenna reflector structure of the second type of reflector antenna provided by the present invention.

[0033] Figure 6 This is a schematic diagram of the shaped antenna reflector structure of the third type of reflector antenna provided by the present invention.

[0034] Figure 7 This is a schematic diagram of the shaped antenna reflector structure of the fourth type of reflector antenna provided by the present invention.

[0035] Figure 8 yes Figure 3 The beamforming principle and schematic diagram of the reflector antenna in the YOZ plane.

[0036] Figure 9 yes Figure 3 The beamforming principle and schematic diagram of the reflector antenna in the XOZ plane.

[0037] Figure 10 This is a simulation diagram of the radiation pattern of the reflector antenna in polar coordinates provided by the present invention.

[0038] Figure 11 This is a simulation diagram of the radiation pattern of the reflector antenna in the corresponding planar coordinate system provided by the present invention.

[0039] Figure 12 This invention provides the principle and schematic diagram of beamforming in the XOZ plane for the fifth reflector antenna.

[0040] Figure 13This invention provides a schematic diagram and principle of beamforming in the YOZ plane for the sixth reflector antenna.

[0041] Figure 14 This invention provides a sixth type of reflective antenna with a beamforming principle and schematic diagram in the XOZ plane.

[0042] Figure 15 This invention provides the seventh reflective antenna and its beamforming principle and schematic diagram in the XOZ plane.

[0043] Figure 16 This invention provides the principle and schematic diagram of beamforming in the YOZ plane for the eighth reflector antenna.

[0044] Figure 17 This invention provides the principle and schematic diagram of beamforming in the XOZ plane of the eighth reflector antenna.

[0045] Figure 18 This invention provides the principle and schematic diagram of beamforming in the XOZ plane for the ninth reflective antenna.

[0046] Figure 19 This is a schematic diagram of the horizontal coverage of the railway by the reflector antenna provided by the present invention.

[0047] Figure label:

[0048] 10. Shaped antenna reflector; 100. Shaped reflector surface; 101. Parabolic reflector surface; 1011. Connecting edge; 102. Sweep reflector surface; 20. Feed source; 300. Sub-reflector surface; 41. Antenna; 42. Rail. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0050] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "first" and "second" are numbered for the purpose of clearly identifying product components and do not represent any substantial difference. The terms "installed," "connected," and "linked" should be interpreted broadly; for example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances. Furthermore, "multiple" means two or more. In the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0051] like Figure 1 and Figure 2 As shown, for safety reasons, the narrow beam antenna 41 cannot be erected above the rail 42. It is usually set on one side of the rail 42 and kept at a safe distance from the rail 42. However, this will result in the antenna 41 having a horizontal zero point phenomenon in the network coverage of the railway on the horizontal plane, with a coverage blind spot in the horizontal direction. In addition, the part of the horizontal main beam that deviates from the rail accounts for a large proportion, resulting in poor coverage along the length of the rail 42.

[0052] To address this, embodiments of the present invention provide a shaped antenna reflector, which is applied to an antenna. The following describes the application of this shaped antenna reflector in conjunction with... Figures 3-19 The shaped antenna reflector and reflector antenna of the present invention are described.

[0053] like Figure 3 and Figure 4 As shown, the shaped antenna reflector 10 provided in this embodiment of the invention has a shaped reflective surface 100. The shaped reflective surface 100 includes a parabolic reflective surface 101 and a swept reflective surface 102. The parabolic reflective surface 101 is at least a portion of a semi-parabolic sphere of revolution, and the swept reflective surface 102 is at least a portion of a swept surface. The generatrix of the semi-parabolic sphere of revolution is a parabolic segment, one end of which is the vertex of the parabola. The semi-parabolic sphere of revolution is formed by rotating the generatrix of revolution about the axis of symmetry of the parabola by 180°. The edge of the parabolic reflective surface 101 has a connecting edge 1011, and the connecting edge 1011 and the generatrix of the semi-parabolic sphere of revolution are located on the same parabola. The swept surface is formed by sweeping the connecting edge 1011 in a direction away from the parabolic reflective surface 101. The swept reflective surface 102 is tangent to the parabolic reflective surface 101 at the connecting edge 1011.

[0054] See Figure 4In a rectangular coordinate system formed by the orthogonal X, Y, and Z axes, the vertex of the parabola segment serving as the generatrix of the semi-parabola of revolution coincides with the origin O of the rectangular coordinate system. The connecting edge 1011 and the generatrix of the semi-parabola of revolution lie on the XOZ plane, and the axis of symmetry of the parabola containing both is the Z-axis. The first plane direction is the direction of the orthogonal plane of the Y and Z axes (hereinafter referred to as the YOZ plane), and the second plane direction is the direction of the orthogonal plane of the X and Z axes (hereinafter referred to as the XOZ plane). It can be understood that the semi-parabola of revolution is formed by rotating the parabola segment OA or OA' on the XOZ plane by 180° around the Z-axis with its vertex as the center.

[0055] Specifically, AOA' is a parabola segment symmetric about the Z-axis, and O is the origin of the rectangular coordinate system, which is also the vertex of the parabola segment AOA'. The equation of the parabola segment AOA' is z = x. 2 / (4f), x∈(-D / 2,D / 2). Where f is the focal length of parabola segment AOA', and D is the aperture of parabola segment AOA'. Connecting edge 1011 is at least a part of parabola segment AOA'.

[0056] The generatrix of the semi-parabolic surface of revolution is the parabola segment OA or OA'. OA or OA' is the portion of the parabola segment AOA' located on one side of its axis of symmetry, i.e., half of the parabola segment AOA'. Furthermore, the connecting edge 1011 and the generatrix of the semi-parabola of revolution lie on the same parabola. The semi-parabolic surface of revolution is formed by rotating the parabola segment OA or OA' 180° around the origin O about the Z-axis. The focus of the semi-parabolic surface of revolution, which is also the focus F of the parabolic reflecting surface 101, lies on the Z-axis.

[0057] In this embodiment of the invention, the parabolic reflector 101 can be a complete semi-parabolic surface of revolution, or it can be obtained by modifying or partially reducing the semi-parabolic surface of revolution as needed. The swept surface is formed by sweeping along a certain path from the connecting edge 1011 away from the parabolic reflector 101. The swept reflector 102 can be a complete swept surface, or it can be obtained by modifying or partially reducing the swept surface as needed.

[0058] The shaped antenna reflector provided in this embodiment of the invention is used in conjunction with the feed source 20 to reflect the spherical wave emitted by the feed source 20, wherein the feed source 20 is disposed on the concave side of the shaped reflector surface 100.

[0059] See Figure 8 and Figure 9The weakly directional spherical emitted wave from feed 20, after being reflected by parabolic reflector 101, has its reflected ray parallel to the Z-axis, forming narrow beams in both the first plane direction (YOZ plane) and the second plane direction (XOZ plane). The weakly directional spherical emitted wave from feed 20, after being reflected by swept reflector 102, forms a scattered wide beam in the first plane direction (see...). Figure 8 ), forming a narrow beam in the second plane direction (see Figure 9 Thus, the weakly directional spherical wave emitted by the feed 20, after being reflected by the entire shaped reflector 100, forms a deformed cosecant square beam in the first planar direction (see...). Figure 8 ), forming a narrow beam in the second plane direction (see Figure 9 ).

[0060] The shaped antenna reflector provided in this embodiment of the invention includes a tangent parabolic reflector 101 and a swept reflector 102. The parabolic reflector 101 is at least a part of a semi-parabolic sphere of revolution, and the swept reflector 102 is a part of a swept reflector. The generatrix of the semi-parabolic sphere of revolution is a parabolic segment, and one end of the parabolic segment is the vertex of the parabola it belongs to. The semi-parabolic sphere of revolution is formed by rotating its generatrix by 180° around the axis of symmetry of the parabola. The parabolic reflector 101 has a connecting edge 1011 located on the same parabola as the generatrix of the semi-parabolic sphere of revolution. The swept reflector is formed by sweeping the connecting edge 1011 in a direction away from the parabolic reflector 101. This shaped antenna reflector can cooperate with a feed 20 so that the spherical wave emitted from the feed 20 is reflected by the shaped reflector 100, and the reflected wave forms a deformed cosecant square beam in the first planar direction (corresponding to the horizontal direction) and a narrow beam in the second planar direction (corresponding to the vertical direction). The deformed cosecant square beam has an asymmetric structure, resulting in a greater energy distribution in the target-side beam (effective beam). Compared to conventional technologies, this improves antenna gain and increases longitudinal coverage. Simultaneously, the horizontal beam eliminates horizontal nulls over a larger area, avoiding coverage blind spots. Furthermore, compared to conventional techniques that achieve deformed cosecant square beams using shaped array antennas, this method is simpler in structure, lower in cost, and easier to manufacture.

[0061] In some embodiments of the present invention, the swept surface is formed by sweeping the connecting edge 1011 along the YOZ plane. It is understood that the swept surface is formed by sweeping along the first plane direction, which allows the reflected beam of the swept reflective surface 102 to achieve more effective coverage in the first plane direction.

[0062] In some embodiments, the swept surface is formed by sweeping the connecting edge 1011 along a straight line. This straight line may coincide with the Y-axis, see [reference needed]. Figure 4The line OC is tangent to the parabolic reflector 101 at point O, and the parabolic segment AOA' sweeps along the line OC to the parabolic segment BCB'. Alternatively, the line extends obliquely away from the concave side of the parabolic reflector 101 relative to the Y-axis.

[0063] In other embodiments, the swept surface is formed by sweeping the connecting edge 1011 along a curve in the YOZ plane. This curve extends in a direction away from the concave side of the parabolic reflector 101 relative to the Y-axis. See also Figure 5 Curve OE is tangent to parabolic reflector 101 at point O. Parabolic segment AOA' sweeps along curve OC' to parabolic segment BEB'.

[0064] It should be noted that the above embodiments only schematically illustrate the scanning path of the swept surface, and the specific sweeping path can be determined based on simulation results.

[0065] It should be noted that the parabolic reflecting surface 101 can be obtained by performing operations such as partial truncation, rounding, chamfering, and reshaping on the semi-parabolic surface. The swept reflecting surface 102 can also be obtained by performing operations such as partial truncation, rounding, chamfering, and reshaping on the swept surface. This is as long as the curvature of the swept surface and the semi-parabolic surface remains unchanged.

[0066] See Figure 4 and Figure 5 The parabolic reflector 101 is a complete semi-parabolic surface of revolution, and the swept reflector 102 is a complete swept surface. The entire parabolic segment AOA' forms the connecting edge 1011.

[0067] See Figure 6 The parabolic reflecting surface 101 is part of a semi-parabolic surface of revolution, and the swept reflecting surface 102 is part of a swept surface. The entire parabolic segment AOA' forms the connecting edge 1011. Figure 4 By partially reducing and modifying the shaped reflective surface 100, the following can be obtained: Figure 6 The shaped reflective surface shown.

[0068] See Figure 7 The parabolic reflecting surface 101 is part of a semi-parabolic surface of revolution, and the swept reflecting surface 102 is part of a swept surface. A portion of the parabolic segment AOA' forms the connecting edge 1011. Figure 4 By partially reducing and modifying the shaped reflective surface 100, the following can be obtained: Figure 7 The shaped reflective surface shown.

[0069] Optionally, the parabolic reflector is part of a semi-parabolic surface of revolution and is located on one side of the YOZ plane. And / or, the corner of the swept reflector away from the parabolic reflector is chamfered or rounded.

[0070] In some embodiments of the present invention, the shaped antenna reflector is a one-piece structure or a split structure. It is understood that the shaped antenna reflector can be integrally formed or formed by splicing multiple components.

[0071] Optionally, the shaped antenna reflector includes a first component and a second component, a parabolic reflector 101 formed on the first component, a swept reflector 102 formed on the second component, and the shaped reflector 100 is formed by splicing the first component and the second component. Alternatively, the shaped antenna reflector includes three or more independent components, each component forming a part of the shaped reflector 100, and multiple components are spliced ​​together to form the shaped reflector 100.

[0072] In some embodiments of the present invention, the shaped antenna reflector 10 is a plate-shaped solid structure, a plate-shaped hollow structure, or a mesh structure. And / or, the shaped antenna reflector is made of aluminum alloy, zinc alloy, steel, or a structure with a metal coating.

[0073] Among them, the hollow structure shaped antenna reflector and the mesh structure shaped antenna reflector can significantly reduce the weight and wind load of the shaped antenna reflector, which is beneficial to improving the installation convenience and structural stability of the shaped antenna reflector. Optionally, the mesh structure is formed by weaving, punching and stretching, or die casting.

[0074] The shaped antenna reflector 10 can be made of metallic materials such as aluminum alloy, zinc alloy, or steel, or of metallic or non-metallic materials with a metallic coating. The shaped antenna reflector can be formed using processes such as stretching, stamping, spinning, or precision casting, based on the material properties.

[0075] Furthermore, the gap width of the plate-like perforated structure and the mesh structure is less than λ / 10, where λ is the wavelength of the antenna's operating frequency. This allows the shaped antenna reflector with the perforated or mesh structure to simulate a solid reflecting surface, ensuring that the reflecting surface can efficiently reflect electromagnetic waves.

[0076] An embodiment of the present invention provides a reflector antenna, such as... Figure 3 As shown, the reflector antenna includes a feed 20 and a shaped antenna reflector 10 as described in any of the above embodiments. Figure 8 and Figure 9 As shown. The feed 20 is located on the concave side of the parabolic reflector 101 and points towards the shaped reflector 100. The radiation phase center of the feed 20 is located at the focal point of the parabolic reflector 101. The focal point F of the parabolic reflector 101 is also the focal point of the shaped reflector 100. The feed 20 can be an oscillator-type feed or a horn-type feed, etc., and is not limited here.

[0077] See Figure 8 The coordinate system in the figure is referenced. Figure 4 , Figure 5On the YOZ plane, the intercept of the parabolic reflector is OC', and the intercept of the swept reflector 102 is OC. The swept reflector 102 does not have focusing capability, while the parabolic reflector 101 does have focusing capability. Figure 8 The weakly directional spherical wave emitted from the right side of the feed source 20 is focused and reflected by the parabolic reflector 101. Because the feed source 20 is located at the focal point F of the parabolic reflector 101, the reflected wave is parallel to the Z-axis, forming a beam of parallel lines. Based on the equivalent parabolic surface theory, the weakly directional spherical wave from the right side of the feed source 20, after being reflected by the parabolic reflector 101, forms a plane wave with a sharp direction. The weakly directional spherical wave emitted from the left side of the feed source 20, after being reflected by the swept reflector 102, forms a scattered wave.

[0078] Through the combined action of the parabolic reflector 101 and the swept reflector 102, the cross-section of the reflected beam of the reflector antenna in the first plane direction (YOZ plane) is wider on the left and narrower on the right, i.e., a deformed cosecant square beam. Simulation results of the radiation pattern are shown below. Figure 9 , Figure 10 The green area represents the direction of the first plane.

[0079] See Figure 9 The coordinate system in the figure is referenced. Figure 4 , Figure 5 The cross-sections of the swept reflector 102 and the parabolic reflector 101 on the XOZ plane are both parabolic segments AOA'. The weakly directional spherical outgoing wave emitted by the feed 20, after reflection by the shaped reflector 100, forms a beam of parallel lines because the feed is located at the focal point F of the parabolic reflector 101. Based on the equivalent parabolic surface theory, Figure 9 The 20 weakly directional spherical waves from the center-feed source are reflected by the shaped reflector 100° to form sharp plane waves. The beam of the reflector antenna has a narrow beam cross-section in the second plane direction (XOZ plane). Simulation results of the radiation pattern are shown below. Figure 9 and Figure 10 The red part represents the direction diagram of the second plane.

[0080] The shaped antenna reflector reflects the spherical wave emitted from the feed 20 located on the concave side of the shaped reflector surface 100. The cross-section of the reflected wave in the first plane direction is a deformed cosecant square beam, and the cross-section in the second plane direction is a narrow beam. The first plane direction is consistent with the direction of the central symmetry plane of the semi-parabolic rotation surface, and the first plane direction and the second plane direction are perpendicular.

[0081] In some of these embodiments, such as Figure 8 As shown, the parabolic reflector 101 is a semi-parabolic surface of revolution. The feed source 20 points to the vertex of the parabola where the generatrix of the semi-parabolic surface of revolution is located, that is, the vertex O of the parabola segment AOA'.

[0082] In other embodiments, see Figure 12 The parabolic reflector 101 is part of a semi-parabolic surface of revolution and is located on one side of the YOZ plane. The feed 20 is located on the XOZ plane and its orientation is at a certain angle to the YOZ plane, so that the feed 20 faces the shaped reflector 100. In this way, the feed 20 can avoid blocking the electromagnetic waves reflected by the shaped reflector 100.

[0083] This invention also provides a reflector antenna. For example... Figure 13 and Figure 14 As shown, the reflector antenna includes a feed 20, a sub-reflector, and a shaped antenna reflector 10 as described in any of the above embodiments. Both the feed 20 and the sub-reflector are located on the concave side of the parabolic reflector 101. The sub-reflector has a sub-reflecting surface 300, which is part of an ellipsoid with its concave side facing the shaped reflector 100. The sub-reflecting surface 300 has a first focus F1 and a second focus F2, with the second focus F2 closer to the sub-reflector 300 relative to the first focus F1. The second focus F2 coincides with the focus F of the parabolic reflector 101. The feed 20 points towards the second focus F2, and its radiation phase center is located at the first focus F1.

[0084] The weakly directional spherical outgoing wave emitted by feed 20 is reflected by the concave side of sub-reflector 300, and its reflected rays converge at the second focal point F2, which is also the focal point F of parabolic reflector 101, equivalent to the outgoing wave emitted at focal point F. According to the principle analysis above, after reflection by shaped reflector 100, the reflected wave has a deformed cosecant square beam in the first plane direction and a narrow beam in the second plane direction. Simulation results of the radiation pattern are shown below. Figure 9 , Figure 10 The green area represents the radiation pattern in the first plane direction, and the red area represents the radiation pattern in the second plane direction.

[0085] In some of these embodiments, such as Figure 14 As shown, the parabolic reflector 101 is a semi-parabolic surface of revolution. The feed source 20 is located on the YOZ plane and points towards the sub-reflector 300.

[0086] In other embodiments, such as Figure 15As shown, the parabolic reflector 101 is part of a semi-parabolic sphere of revolution and is located on one side of the YOZ plane. The feed 20 is offset on the XOZ plane with its focal point F as the center, towards the other side of the YOZ plane. It can be understood that the shaped antenna reflector 10 and the feed 20 are located on opposite sides of the YOZ plane. On the XOZ plane, the line connecting the first focal point F1 and the second focal point F2 of the sub-reflector 300 is angled to the YOZ plane. This prevents the feed 20 from blocking the electromagnetic waves reflected by the parabolic reflector 101. The parabolic reflector 101 can be obtained by truncating the semi-parabolic sphere of revolution, and the sub-reflector 300 can also be truncated as needed.

[0087] This invention also provides a reflector antenna. For example... Figure 16 and Figure 17 As shown, the reflector antenna includes a feed 20, a sub-reflector, and a shaped antenna reflector 10 as described in any of the above embodiments. Both the feed 20 and the sub-reflector are located on the concave side of the parabolic reflector 101. The sub-reflector has a sub-reflecting surface 300, which is at least a portion of one branch of a two-leaf hyperboloid and its convex side faces the shaped reflector 100. The virtual focus F3 of the sub-reflecting surface 300 coincides with the focus F of the parabolic reflector 101. The feed 20 points towards the virtual focus F3 of the sub-reflector, and its radiation phase center is located at the virtual focus F4 of the other branch of the two-leaf hyperboloid.

[0088] The weakly directional spherical outgoing wave emitted by feed 20 is reflected by the convex side of sub-reflector 300. The extensions of the reflected rays converge at the virtual focal point F3 of sub-reflector 300, which is also the focal point F of parabolic reflector 101, equivalent to the outgoing wave emitted from focal point F. According to the principle analysis above, after reflection by shaped reflector 100, the reflected wave has a deformed cosecant square beam in the first plane direction and a narrow beam in the second plane direction. Simulation results of the radiation pattern are shown below. Figure 9 , Figure 10 The green area represents the radiation pattern in the first plane direction, and the red area represents the radiation pattern in the second plane direction.

[0089] In some of these embodiments, such as Figure 17 As shown, the parabolic reflector 101 is a semi-parabolic surface of revolution. The feed source 20 is located on the YOZ plane and points towards the sub-reflector 300.

[0090] In other embodiments, such as Figure 18As shown, the parabolic reflector 101 is part of a semi-parabolic sphere and is located on one side of the YOZ plane. The feed 20 is offset on the XOZ plane with the focal point F of the parabolic reflector 101 as the center and to the other side of the YOZ plane. It can be understood that the shaped antenna reflector 10 and the feed 20 are located on opposite sides of the YOZ plane, and on the XOZ plane, the line connecting the virtual focal points F3 and F4 is angled to the YOZ plane. This avoids the feed 20 from blocking the electromagnetic waves reflected by the parabolic reflector 101. The parabolic reflector 101 can be obtained by truncating the semi-parabolic sphere, and the sub-reflector 300 can also be truncated as needed.

[0091] In practical applications, such as Figure 19 As shown, antenna 41 is mounted on a communication tower, and the mounting angle of antenna 41 is adjusted so that the deformed cosecant square beam in the first plane direction covers the length direction of the railway. In the length direction of the railway, the beam reflected by the swept reflector 102 covers the area close to the communication tower, and the beam reflected by the parabolic reflector 101 covers the area far from the communication tower.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A shaped antenna reflector, characterized in that, The shaped antenna reflector has a shaped reflective surface, which includes a parabolic reflective surface and a swept reflective surface; The parabolic reflector is at least a portion of a semi-parabolic surface of revolution, and the swept reflector is at least a portion of a swept surface. The generatrix of the semi-parabolic surface of revolution is a parabolic segment, one end of which is the vertex of the parabola. The semi-parabolic surface of revolution is formed by rotating the generatrix around the axis of symmetry of the parabola by 180°. In a rectangular coordinate system formed by the orthogonal X-axis, Y-axis, and Z-axis, the vertex coincides with the origin O of the rectangular coordinate system. The edge of the parabolic reflector has a connecting edge, which is located on the same parabola as the generatrix of the semi-parabolic surface of revolution. The swept surface is formed by sweeping the connecting edge along a straight line away from the parabolic reflector. The connecting edge is located on the XOZ plane, and the axis of symmetry is the Z-axis. The straight line coincides with the Y-axis or extends obliquely relative to the Y-axis in a direction away from the concave side of the parabolic reflector. The swept reflector is tangent to the parabolic reflector at the connecting edge. The shaped reflector is used to reflect spherical waves emitted from a feed located on the concave side of the parabolic reflector. The reflected beam is a deformed cosecant square beam in the first plane direction and a narrow beam in the second plane direction. The first plane direction is consistent with the direction of the central symmetry plane of the semi-parabolic surface, and the first plane direction and the second plane direction are perpendicular. The first plane direction is the direction of the YOZ plane, and the second plane direction is the direction of the XOZ plane. The swept surface is formed by sweeping the connecting edge along the YOZ plane. Wherein, the first plane direction is horizontal, the second plane direction is vertical, the portion of the deformed cosecant square beam reflected by the parabolic reflector is used for focusing towards the far end; the portion of the deformed cosecant square beam reflected by the swept reflector is used for scattering towards the near end.

2. The shaped antenna reflector according to claim 1, characterized in that, The parabolic reflecting surface is part of a semi-parabolic surface of revolution and is located on one side of the YOZ plane; And / or, the corner of the swept reflective surface away from the parabolic reflective surface is chamfered or rounded.

3. The shaped antenna reflector according to claim 1, characterized in that, The shaped antenna reflector can be an integrated structure or a split structure; And / or, the shaped antenna reflector is a plate-shaped solid structure, a plate-shaped hollow structure, or a mesh structure; And / or, the shaped antenna reflector is made of aluminum alloy, zinc alloy, steel, or has a metal coating.

4. The shaped antenna reflector according to claim 3, characterized in that, The gap width of the plate-shaped hollow structure and the mesh structure is less than λ / 10, where λ is the operating frequency wavelength of the antenna.

5. A reflector antenna, characterized in that, include: The feed source and the shaped antenna reflector according to any one of claims 1 to 4; The feed source is located on the concave side of the parabolic reflector and points towards the shaped reflector, and the radiation phase center of the feed source is located at the focal point of the parabolic reflector.

6. A reflector antenna, characterized in that, include: The feed, the sub-reflector, and the shaped antenna reflector according to any one of claims 1 to 4, wherein the feed and the sub-reflector are both located on the concave side of the parabolic reflector; The sub-reflector has a sub-reflecting surface, which is part of an ellipsoid with its concave side facing the shaped reflecting surface. The sub-reflecting surface has a first focal point and a second focal point, with the second focal point being closer to the sub-reflecting surface than the first focal point. The second focal point coincides with the focal point of the parabolic reflecting surface. The feed source is directed to the second focal point, and its radiation phase center is located at the first focal point.

7. A reflector antenna, characterized in that, include: The feed, the sub-reflector, and the shaped antenna reflector according to any one of claims 1 to 4, wherein the feed and the sub-reflector are both located on the concave side of the parabolic reflector; The sub-reflector has a sub-reflecting surface, which is at least a portion of one branch of a double-leaf hyperboloid and its convex side faces the shaped reflecting surface. The virtual focal point of the sub-reflecting surface coincides with the focal point of the parabolic reflecting surface. The feed point is directed to the virtual focus of the sub-reflector, and its radiation phase center is located at the virtual focus of the other branch of the double-leaf hyperboloid.

8. The reflector antenna according to claim 6 or 7, characterized in that, The parabolic reflector is part of a semi-parabolic surface of revolution and is located on one side of the YOZ plane. The feed source is offset on the XOZ plane with the focus of the parabolic reflector as the center and to the other side of the YOZ plane.

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