A communication electromagnetic wave adjustable linear polarization to circular polarization spherical lens antenna and a manufacturing method thereof, a communication base station, a communication system and a communication method

Abstract

The application discloses a communication electromagnetic wave adjustable linear polarization to circular polarization spherical lens antenna and a manufacturing method, a communication base station, a communication system and a communication method, and belongs to the technical field of antennas in electronic communication. The antenna comprises a controllable polarization spherical lens and a linear polarization feed source. The feed source is used for emitting a polarization electromagnetic wave with a linear polarization direction and a main axis direction at an inclined angle in the direction of the sphere; the length of the axial baseband of the electromagnetic baseband unit is configured to be greater than the radial baseband, so that the refractive index of the electromagnetic wave along the main axis direction is greater than that along the radial direction; when the feed source is located at the equatorial part of the moving track, the electromagnetic wave is circularly polarized after being regulated by the lens; when the feed source is located at the spherical end part of the moving track, the polarization direction of the electromagnetic wave is unchanged after passing through the lens; when the feed source is located between the equatorial part and the spherical end part, the electromagnetic wave is elliptically polarized after being regulated by the lens. The three functions of high gain wide angle scanning, wideband operation and polarization state adjustment are realized.

Description

Technical Field

[0001] This invention belongs to the field of antenna technology in electronic communication, specifically relating to a spherical lens antenna with adjustable linear polarization to circular polarization for communication electromagnetic waves, its manufacturing method, and communication base stations, communication systems, and communication methods. Background Technology

[0002] With the rapid development of next-generation mobile communication technologies (B5G / 6G), communication systems are placing higher demands on antenna performance, especially in terms of large bandwidth, high gain, wide-angle beam scanning, and circularly polarized radiation. Circularly polarized antennas can reduce multipath interference and polarization mismatch, and have important applications in satellite communication, radar, and high-speed mobile communication. For example, Chinese Patent Publication No. CN107749520B discloses a high-gain millimeter-wave circularly polarized array antenna. This prior art technology, through the isolation characteristics of the second and third metal layers, greatly reduces the radiation impact of the feed network on the radiating element.

[0003] However, current antennas that achieve linear polarization to circular polarization conversion mostly rely on constructing traditional dielectric filling structures with bidirectional polarization. For example... Fig. 2-3 As shown, such dielectric filling structures typically have different filling rates in their two mutually orthogonal polarization component directions (such as the x-direction and y-direction) to achieve different equivalent dielectric constants, thereby causing the incident linearly polarized electromagnetic wave to have a different propagation phase in the two orthogonal polarization component directions, and finally converting it into a circularly polarized electromagnetic wave.

[0004] However, current antennas based on traditional dielectric filling structures still have the following drawbacks:

[0005] First, the manufacturing complexity is high; in order to achieve a precise gradient of dielectric constant, complex processes such as precision injection molding or sintering are usually required, and the tolerance of the product is strictly required to be ±0.1mm, resulting in a processing cycle of up to 2-4 weeks and high costs.

[0006] Second, the operating bandwidth is limited; the dielectric material that makes up the traditional dielectric filling structure has dispersion characteristics, and its electromagnetic parameters change with frequency, which limits the operating bandwidth of the antenna and makes it difficult to meet the needs of ultra-wideband communication systems. Summary of the Invention

[0007] To address the problems in related technologies, this invention proposes a spherical lens antenna with adjustable linear polarization to circular polarization for communication electromagnetic waves, its manufacturing method, and a communication base station, communication system, and communication method, thereby overcoming the aforementioned technical problems existing in existing related technologies. The spherical lens antenna of this invention, through a controllable polarization spherical lens composed of a non-metallic sheet substrate containing a specific tubular cavity and an electromagnetic baseband unit, combined with a linearly polarized feed that can move along a specific trajectory, enables linearly polarized electromagnetic waves to be emitted in either a constant polarization direction, elliptical polarization, or circular polarization depending on the feed position, flexibly adjusting the polarization state of the electromagnetic waves. It also achieves three major functions: high-gain wide-angle scanning, broadband operation, and dynamically adjustable polarization state. Furthermore, its structure is relatively simple and low-cost, making it highly suitable for B5G / 6G communication systems, multi-functional radars, and satellite communication terminals.

[0008] The technical solution of the present invention is implemented as follows: a spherical lens antenna with adjustable linear polarization to circular polarization for communication electromagnetic waves, comprising a controllable polarization spherical lens and a linear polarization feed.

[0009] The controllable polarization spherical lens is a sphere made of a non-metallic sheet substrate. The sphere has multiple tubular cavities that extend parallel to the main axis. Multiple electromagnetic baseband units made of metal are arranged on the inner wall of the tubular cavities. The electromagnetic baseband units include an axial baseband that extends parallel to the main axis of the tubular cavity and a radial baseband that is perpendicular to the main axis.

[0010] A spherical end from either end of the tubular cavity along the main axis is configured with a movement trajectory extending to the equator of the sphere along the outer surface of the sphere, and the linearly polarized feed source is configured on the movement trajectory. The linearly polarized feed source is used to emit polarized electromagnetic waves with the linear polarization direction at an angle to the main axis direction towards the sphere.

[0011] The axial baseband of the electromagnetic baseband unit is configured to be longer than the radial baseband, so that the refractive index of the electromagnetic wave along the main axis is greater than the refractive index along the radial direction; when the linearly polarized feed source is located at the equator of the moving trajectory, its electromagnetic wave is emitted in circular polarization after being controlled by the spherical lens.

[0012] Furthermore, when the linearly polarized feed is located at the end of the sphere in the moving trajectory, its electromagnetic wave remains polarized after passing through the spherical lens; when the feed is located between the equator and the end of the sphere, its electromagnetic wave is emitted in elliptical polarization after being controlled by the spherical lens.

[0013] Furthermore, it also includes a drive mechanism for controlling the rotation of the spherical lens. By controlling the spherical lens to rotate along the moving trajectory, the outer surface of the spherical lens and the linearly polarized feed source move relative to each other on the moving trajectory. During the relative movement, the angle between the linear polarization direction of the electromagnetic wave emitted by the linearly polarized feed source and the main axis direction does not change.

[0014] Furthermore, it also includes a drive mechanism for controlling the movement of the linearly polarized feed source. By controlling the linearly polarized feed source to move along the moving trajectory, the relative position of the linearly polarized feed source and the outer surface of the spherical lens changes, and the angle between the linear polarization direction of the electromagnetic wave emitted during the movement of the linearly polarized feed source and the main axis remains unchanged.

[0015] Furthermore, multiple fixed linearly polarized feed sources are configured along the moving trajectory, and the linearly polarized feed sources are fixed relative to the spherical lens;

[0016] Multiple linearly polarized feed sources are controlled independently.

[0017] Furthermore, it also includes multiple linearly polarized feed sources fixed at the equatorial portion of the spherical lens, the linearly polarized feed sources surrounding the outer periphery of the spherical lens along the equatorial portion, and the feed source surrounding plane being perpendicular to the main axis direction.

[0018] Furthermore, the movement trajectory is configured as multiple tracks.

[0019] Furthermore, the movement trajectory is set on a plane passing through the central main axis of the spherical lens;

[0020] The trajectory of movement includes at least the length from the end of the sphere to the equator of the sphere.

[0021] Furthermore, the tubular cavity extends through the spherical lens at both ends along the main axis;

[0022] The cross-sectional shape of the tubular cavity is polygonal or circular.

[0023] Furthermore, the tilt angle between the linear polarization direction and the main axis direction of the electromagnetic wave emitted by the linearly polarized feed source is set to the middle 45° angle.

[0024] Let the axial baseband extend in the Y-axis direction, and the radial baseband extend in the X-axis direction;

[0025] Linearly polarized electromagnetic waves have equal components in the Y and X directions;

[0026] The refractive index in the Y direction and the refractive index in the X direction conform to the following relationship:

[0027] ;

[0028] in, Let X be the refractive index in the X direction. The refractive index is in the Y direction. R is the wavelength of the operating frequency band, R is the radius of the spherical lens, and r is the radial length from the center of the spherical lens.

[0029] Furthermore, after the electromagnetic wave emitted by the linearly polarized feed source is emitted through the spherical lens, the phase difference between the electromagnetic wave components in the Y and X directions is 90°. The tilt angle between the polarization direction of the electromagnetic wave emitted by the linearly polarized feed source and the main axis direction is set to +45° or -45°, so that the electromagnetic wave refracted by the spherical lens forms a left-hand circular polarization or a right-hand circular polarization emission.

[0030] Furthermore, the axial baseband length of the electromagnetic baseband unit near the center of the sphere is configured to be greater than the axial baseband length of the electromagnetic baseband unit far from the center of the sphere, and the radial baseband length of the electromagnetic baseband unit near the center of the sphere is configured to be greater than the radial baseband length of the electromagnetic baseband unit far from the center of the sphere; so that the refractive index of the spherical lens near the center position is greater than the refractive index far from the center position, so that the electromagnetic wave incident as a spherical wave is refracted by the spherical lens into a plane wave and emitted.

[0031] Furthermore, the refractive index within the spherical lens gradually decreases radially from the center of the sphere to the surface of the sphere;

[0032] The refractive index along the X direction satisfies the following formula:

[0033] ;

[0034] in, R is the refractive index in the X direction at the center of the spherical lens; R is the radius of the spherical lens; r is the radial length from the center of the spherical lens.

[0035] The refractive index along the Y direction satisfies the following formula:

[0036] ;

[0037] in, Let be the refractive index in the Y direction at the center of the spherical lens.

[0038] Furthermore, the spherical lens includes a first refractive layer, a second refractive layer, a third refractive layer, ... and an Nth refractive layer arranged sequentially from the center of the sphere to the surface of the sphere, and the multiple refractive layers are arranged concentrically, where N is a positive integer; each of the refractive layers contains the electromagnetic baseband unit, and the refractive index between the refractive layers decreases stepwise from the inner layer to the outer layer.

[0039] Furthermore, the tilt angle between the linear polarization direction and the principal axis direction of the electromagnetic wave emitted by the linearly polarized feed source is set to a midpoint of 45°; the extension direction of the axial baseband is defined as the Y-axis direction, and the extension direction of the radial baseband is defined as the X-axis direction; the components of the linearly polarized electromagnetic wave in the Y and X directions are equivalent; the refractive indices in the Y and X directions of each refractive layer conform to the following relationship:

[0040] ;

[0041] in, The refractive index is in the X direction. The refractive index is in the Y direction; The wavelength of the operating frequency band; For the first i Radial thickness of the refractive layer.

[0042] A method for manufacturing a spherical lens antenna as described above includes the following steps:

[0043] Step A: Prepare a non-metallic sheet substrate, and arrange the electromagnetic baseband units of the metal thin film material at intervals on the surface of the sheet substrate, so that all axial basebands are arranged in the same direction parallel to the main axis, and all radial basebands are arranged in the same direction perpendicular to the main axis, and arrange the axial baseband length of each electromagnetic baseband unit to be greater than its radial baseband length.

[0044] Step B: Cut multiple sheet substrates to the preset size according to the size of the sphere;

[0045] Step C: Fold or bend the sheet substrate in a direction parallel to the main axis to form multiple bonding beams with alternating concave and convex shapes and multiple cavity grooves. Bond and fix the bonding beams of the multiple sheet substrates from left to right, so that the cavity grooves are connected to each other to form multiple tubular cavities parallel to the main axis.

[0046] Step D: The linearly polarized feed source is positioned along the movement trajectory of the spherical lens from the end of the sphere located at any end of the main axis direction to the equator of the sphere. The linear polarization direction of the electromagnetic wave emitted by the feed source is adjusted and tilted relative to the main axis direction.

[0047] Furthermore, the sphere is constructed into multiple layers with different refractive indices from the center of the spherical lens outwards. The refractive indices are the same within the same layer, and the refractive indices of different layers decrease from the inside to the outside. In step A, the electromagnetic baseband units located in the same refractive layer are arranged as identical units.

[0048] A communication base station includes a spherical lens antenna as described above.

[0049] A communication system comprising a communication base station as described above.

[0050] A communication method for a communication system as described above includes one of the following steps:

[0051] Step H: Control the spherical lens to rotate dynamically relative to the moving trajectory according to a set program, so as to dynamically change the polarization state of the emitted communication electromagnetic wave, and control the communication electromagnetic wave signal receiving end to synchronously adjust the polarization direction of the receiving antenna to match the polarization state of the emitted electromagnetic wave.

[0052] Step 1: Control the linearly polarized feed source to move dynamically along the moving trajectory according to the set program, so as to dynamically change the polarization state or the emission direction of the emitted communication electromagnetic wave, and control the communication electromagnetic wave signal receiving end to synchronously adjust the polarization state or receiving direction of the receiving antenna to match the emitted electromagnetic wave.

[0053] Step J: Configure multiple fixed linearly polarized feed sources along the moving trajectory, control the working state of the linearly polarized feed sources at different positions according to the set program to dynamically change the polarization state of the emitted electromagnetic wave or the radiation coverage range of the electromagnetic wave, and control the communication electromagnetic wave signal receiving end to synchronously adjust the working state of the receiving antenna.

[0054] Furthermore, the setup procedure is distributed as a key between the communication base station and the signal receiving end.

[0055] The beneficial effects of this invention are:

[0056] (1) The spherical lens antenna of the present invention, through a controllable polarization spherical lens composed of a non-metallic sheet substrate and containing a specific tubular cavity and an electromagnetic baseband unit, combined with a linearly polarized feed that can move along a specific moving trajectory, achieves high gain and wide-angle beam scanning capability, and the working bandwidth is also significantly widened and covers 5.5-8GHz, meeting the broadband requirements of the next generation of communication.

[0057] (2) This invention cleverly achieves active control of the polarization of the output electromagnetic wave by means of the physical displacement of the linearly polarized feed on a specific moving trajectory on the surface of the sphere (such as from the equator to the end of the sphere); this enables a single antenna system to continuously switch between pure linear polarization, elliptical polarization and pure circular polarization as needed, without the need to replace hardware or introduce a complex feed network; this dynamic adjustability significantly improves the functional flexibility of the antenna, enabling it to adapt to different polarization requirements of various communication scenarios.

[0058] (3) Moreover, the invention integrates the polarization control function into the spherical lens itself; since the spherical lens is made of non-metallic substrate and inner wall electromagnetic baseband unit, the overall structure is lightweight and has anisotropic electromagnetic characteristics. Furthermore, the entire spherical lens does not require complex gradient doping or precision processing, making it easy to manufacture and with relaxed tolerance requirements, which significantly reduces costs and can shorten the production cycle to 3 days.

[0059] (4) Finally, by designing the layered arrangement of subwavelength electromagnetic baseband units in the spherical lens, the equivalent refractive index of the spherical lens in different directions and radial positions is precisely controlled, thereby achieving precise control of polarization conversion and wavefront transformation functions. Attached Figure Description

[0060] Fig. 1 This is a schematic diagram of the spherical lens of the present invention;

[0061] Fig. 2 This is a partial structural diagram of a conventional dielectric filling structure in the prior art;

[0062] Fig. 3 This is a schematic diagram of the structure of an antenna that achieves linear-to-circular polarization conversion in the prior art;

[0063] Fig. 4 This is a schematic diagram of the structure of the linearly polarized feed source scanning the cross section around the equator of the present invention;

[0064] Fig. 5 This is a schematic diagram of the structure of the linearly polarized feed source scanning the cross-section of the end of the sphere.

[0065] Fig. 6 This is an optical path diagram showing the electromagnetic wave trajectory and the polarization state of the emitted wave at different positions of the linearly polarized feed at the equatorial section of the present invention.

[0066] Fig. 7 This is an optical path diagram showing the electromagnetic wave trajectory and the polarization state of the emitted wave at different positions of the linearly polarized feed source at the end section of the sphere according to the present invention.

[0067] Fig. 8 This is a schematic diagram showing the refractive index variations of the X and Y components of the multiple refractive layers of the present invention.

[0068] Fig. 9 This is a schematic diagram of the structure of the metal electromagnetic strip of the present invention attached to aramid paper;

[0069] Fig. 10 This is a schematic diagram of the subwavelength electromagnetic baseband unit structure corresponding to different refractive indices of the present invention.

[0070] Fig. 11 The first subwavelength electromagnetic baseband unit structure of the present invention is shown in the curve comparison diagram of the equivalent refractive index decomposition into X-direction components and Y-direction components on the equatorial section and the spherical end section under the illumination of electromagnetic waves incident at different angles.

[0071] Fig. 12 The curves showing the equivalent refractive index decomposition into X-direction and Y-direction components at the equatorial section and the end section of the sphere under electromagnetic wave irradiation at different angles for the second subwavelength electromagnetic baseband unit structure of the present invention are shown.

[0072] Fig. 13 The curves showing the equivalent refractive index decomposition into X-direction and Y-direction components at the equatorial section and the spherical end section of the third subwavelength electromagnetic baseband unit structure of the present invention under the irradiation of electromagnetic waves incident at different angles are compared.

[0073] Fig. 14The graph shows the equivalent refractive index decomposition into X-direction and Y-direction components on the equatorial section and the spherical end section of the fourth subwavelength electromagnetic baseband unit structure of the present invention under the irradiation of electromagnetic waves incident at different angles.

[0074] Fig. 15 This is a schematic diagram of the structure of the linearly polarized feed source of the present invention, which feeds into the dielectric lens at different positions along the equatorial section.

[0075] Fig. 16 This is a schematic diagram of the structure of the linearly polarized feed source of the present invention feeding into the dielectric lens at different positions along the end section of the sphere;

[0076] Fig. 17 The antenna radiation pattern of the linearly polarized feed of the present invention is shown when it is incident at different angles along the equatorial section.

[0077] Fig. 18 This is a diagram showing the axial ratio of the antenna when the linearly polarized feed of the present invention is incident at different angles along the equatorial section.

[0078] Fig. 19 The antenna radiation pattern of the linearly polarized feed of the present invention is shown when it is incident at different angles along the equatorial section.

[0079] Fig. 20 This is a diagram showing the antenna axial ratio of the linearly polarized feed of the present invention when incident at different angles along the cross-section at the end of the sphere. Detailed Implementation

[0080] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0081] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0082] Example 1

[0083] like Fig. 1-10As shown, this embodiment provides a spherical lens antenna with adjustable linear polarization to circular polarization for communication electromagnetic waves, including a controllable polarization spherical lens and a linear polarization feed.

[0084] The controllable polarization spherical lens is a sphere made of a non-metallic sheet substrate. The sphere has multiple tubular cavities that extend parallel to the main axis. Multiple electromagnetic baseband units made of metal are arranged on the inner wall of the tubular cavities. The electromagnetic baseband units include an axial baseband that extends parallel to the main axis of the tubular cavity and a radial baseband that is perpendicular to the main axis.

[0085] A spherical end from either end of the tubular cavity along the main axis is configured with a movement trajectory extending to the equator of the sphere along the outer surface of the sphere, and the linearly polarized feed source is configured on the movement trajectory. The linearly polarized feed source is used to emit polarized electromagnetic waves with the linear polarization direction at an angle to the main axis direction towards the sphere.

[0086] The linearly polarized feed source can be placed at any position on the surface of the spherical lens;

[0087] The axial baseband of the electromagnetic baseband unit is configured to be longer than the radial baseband, so that the refractive index of the electromagnetic wave along the main axis is greater than the refractive index along the radial direction.

[0088] It should be noted that: in this embodiment, "the length of the axial baseband of the electromagnetic baseband unit is configured to be greater than the radial baseband" specifically means that the total length of the axial baseband is greater than the total length of the radial baseband.

[0089] like Fig. 9-10 As shown, on a single sheet substrate, each of the electromagnetic baseband units has a cross-shaped structure; however, in practical applications, each of the electromagnetic baseband units may have a cross-shaped structure, such as a T-shaped structure, etc.

[0090] Taking the cross-shaped structure as an example, the cross-shaped structure includes an axial baseband and a radial baseband. The length of the single axial baseband can be set to be greater than the length of the single radial baseband.

[0091] Taking the T-shaped structure as an example, the T-shaped structure includes an axial baseband and a radial baseband. The length of the single axial baseband can be set to be greater than the length of the single radial baseband.

[0092] When the linearly polarized feed is located at the equator of the moving trajectory, its electromagnetic waves are emitted in circular polarization after being controlled by a spherical lens.

[0093] Furthermore, when the linearly polarized feed is located at the end of the sphere in the moving trajectory, its electromagnetic wave remains polarized after passing through the spherical lens; when the feed is located between the equator and the end of the sphere, its electromagnetic wave is emitted in elliptical polarization after being controlled by the spherical lens.

[0094] In this embodiment, the spherical lens antenna, through a controllable polarization spherical lens composed of a non-metallic sheet substrate and containing a specific tubular cavity and an electromagnetic baseband unit, and in conjunction with a linearly polarized feed that can move along a specific trajectory, can realize that the linearly polarized electromagnetic wave is emitted in the form of constant polarization direction, elliptical polarization, or circular polarization depending on the position of the feed, and the polarization state of the electromagnetic wave can be flexibly adjusted.

[0095] Specifically, it also includes a drive mechanism for controlling the rotation of the spherical lens. By controlling the spherical lens to rotate along the moving trajectory, the outer surface of the spherical lens and the linearly polarized feed source move relative to each other on the moving trajectory. During the relative movement, the angle between the linear polarization direction of the electromagnetic wave emitted by the linearly polarized feed source and the main axis direction does not change.

[0096] Specifically, it also includes a drive mechanism for controlling the movement of the linearly polarized feed source. By controlling the linearly polarized feed source to move along the moving trajectory, the relative position of the linearly polarized feed source and the outer surface of the spherical lens changes, and the angle between the linear polarization direction of the electromagnetic wave emitted during the movement of the linearly polarized feed source and the main axis remains unchanged.

[0097] Specifically, multiple fixed linearly polarized feed sources are configured along the moving trajectory, and the linearly polarized feed sources are fixed relative to the spherical lens;

[0098] Multiple linearly polarized feed sources are controlled independently.

[0099] Specifically, it also includes a plurality of linearly polarized feed sources fixed at the equatorial portion of the spherical lens, the linearly polarized feed sources surrounding the outer periphery of the spherical lens along the equatorial portion, and the feed source surrounding plane being perpendicular to the main axis direction;

[0100] like Fig. 4 As shown, the moving trajectory of the linearly polarized feed surrounds the outer periphery of the equator, and the plane formed by the feed surrounding the equator is defined as the equatorial section.

[0101] Specifically, the movement trajectory is configured as multiple trajectories.

[0102] Specifically, the movement trajectory is set on a plane passing through the central main axis of the spherical lens;

[0103] The trajectory of movement includes at least the length from the end of the sphere to the equator of the sphere;

[0104] like Fig. 5 As shown, the moving trajectory of the linearly polarized feed source is from the end of the sphere to the equator of the sphere, and the plane formed by the feed source around the two ends of the sphere is defined as the end section of the sphere; the end section of the sphere is perpendicular to the equator section.

[0105] Specifically, the tubular cavity extends through the spherical lens at both ends along the main axis;

[0106] The cross-sectional shape of the tubular cavity is polygonal or circular.

[0107] Specifically, the tilt angle between the linear polarization direction and the main axis direction of the electromagnetic wave emitted by the linearly polarized feed source is set to the middle 45° angle.

[0108] Let the axial baseband extend in the Y-axis direction, and the radial baseband extend in the X-axis direction;

[0109] Linearly polarized electromagnetic waves have equal components in the Y and X directions;

[0110] More specifically, a linearly polarized spherical wave can be decomposed into X-direction components and Y-direction components of equal vector magnitude;

[0111] The refractive index in the Y direction and the refractive index in the X direction conform to the following relationship:

[0112] ;

[0113] in, Let X be the refractive index in the X direction. The refractive index is in the Y direction. R is the wavelength of the operating frequency band, R is the radius of the spherical lens, and r is the radial length from the center of the spherical lens.

[0114] Specifically, after the electromagnetic wave emitted by the linearly polarized feed source is emitted through the spherical lens, the phase difference between the electromagnetic wave components in the Y direction and the X direction is 90°. The tilt angle between the polarization direction of the electromagnetic wave emitted by the linearly polarized feed source and the main axis direction is set to +45° or -45°, so that the electromagnetic wave refracted by the spherical lens forms a left-hand circular polarization or a right-hand circular polarization emission.

[0115] It should be noted that in this embodiment, the linearly polarized feed emits a single electromagnetic wave, and the angle between the polarization direction of this electromagnetic wave and the principal axis is set to +45° or -45°. In practical applications, two electromagnetic waves are incident, and the two electromagnetic waves are combined into one electromagnetic wave, with the angle between the combined electromagnetic wave and the principal axis being +45° or -45°, which also has the same effect as the linearly polarized feed emitting a single electromagnetic wave.

[0116] Specifically, the axial baseband length of the electromagnetic baseband unit near the center of the sphere is configured to be greater than the axial baseband length of the electromagnetic baseband unit far from the center of the sphere, and the radial baseband length of the electromagnetic baseband unit near the center of the sphere is configured to be greater than the radial baseband length of the electromagnetic baseband unit far from the center of the sphere; so that the refractive index of the spherical lens near the center is greater than the refractive index far from the center, so that the electromagnetic wave incident as a spherical wave is refracted by the spherical lens into a plane wave and emitted.

[0117] It should be noted that, regardless of how the polarization state and rotation direction of the linearly polarized electromagnetic wave change in this embodiment, the spherical lens functions similarly to a Luneburg lens, capable of converting incident spherical waves from any point on the surface into high-gain plane waves emitted from the other side of the sphere.

[0118] Specifically, the refractive index within the spherical lens gradually decreases from high to low along the radial direction from the center of the sphere to the surface of the sphere;

[0119] The refractive index along the X direction satisfies the following formula:

[0120] (1);

[0121] in, R is the refractive index in the X direction at the center of the spherical lens; R is the radius of the spherical lens; r is the radial length from the center of the spherical lens.

[0122] The refractive index along the Y direction satisfies the following formula:

[0123] (2);

[0124] in, The refractive index in the Y direction at the center of the spherical lens; the refractive index in the X or Y direction at each point on the aperture surface of the spherical lens can be calculated using the two formulas above.

[0125] like Fig. 8 As shown, the spherical lens includes a first refractive layer, a second refractive layer, a third refractive layer, ... and a fourth refractive layer arranged sequentially from the center of the sphere to the surface of the sphere, and the multiple refractive layers are arranged concentrically; each of the refractive layers contains the electromagnetic baseband unit, and the refractive index between the refractive layers decreases stepwise from the inner layer to the outer layer.

[0126] Specifically, the tilt angle between the linear polarization direction and the principal axis direction of the electromagnetic wave emitted by the linearly polarized feed source is set to a midpoint of 45°; the extension direction of the axial baseband is defined as the Y-axis direction, and the extension direction of the radial baseband is defined as the X-axis direction; the components of the linearly polarized electromagnetic wave in the Y and X directions are equivalent; the refractive indices in the Y and X directions of each refractive layer conform to the following relationship:

[0127] (3);

[0128] in, The refractive index is in the X direction. The refractive index is in the Y direction; The wavelength of the operating frequency band; For the first i Radial thickness of the refractive layer, iare positive integers and In this embodiment, N=4;

[0129] like Fig. 8 As shown, in this embodiment, the radius R of the spherical lens is 60mm, and the spherical lens is uniformly divided into four refractive layers, with each layer spaced 15mm apart.

[0130] According to formula (3), the refractive index difference between the X-direction component and the Y-direction component of each refractive layer is 0.11; the specific refractive indices of the X-direction component and the Y-direction component of multiple refractive layers are as follows:

[0131] In the first refractive layer, the refractive index of the X-direction component is 1.11, and the refractive index of the Y-direction component is 1.22.

[0132] In the second refractive layer, the refractive index of the X-direction component is 1.27, and the refractive index of the Y-direction component is 1.38.

[0133] In the third refractive layer, the refractive index of the X-direction component is 1.36, and the refractive index of the Y-direction component is 1.47.

[0134] In the fourth refractive layer, the refractive index of the X-direction component is 1.40, and the refractive index of the Y-direction component is 1.51.

[0135] To achieve different refractive indices for electromagnetic waves in the X and Y directions, a subwavelength electromagnetic baseband unit was designed, such as... Fig. 9 As shown in Figure 10, four subwavelength electromagnetic baseband unit structures with different refractive indices were obtained through electromagnetic simulation. These four subwavelength electromagnetic baseband unit structures correspond to different refractive indices and are defined as the first subwavelength electromagnetic baseband unit structure, the second subwavelength electromagnetic baseband unit structure, the third subwavelength electromagnetic baseband unit structure, and the fourth subwavelength electromagnetic baseband unit structure. They were then filled into the refractive layer corresponding to the spherical lens (e.g., the first subwavelength electromagnetic baseband unit structure was filled into the first refractive layer).

[0136] Among them, the metal surface area of ​​the first, second, third, and fourth subwavelength electromagnetic baseband unit structures increases sequentially.

[0137] Fig. 11-16 The equivalent refractive index of the first, second, third, and fourth subwavelength electromagnetic baseband unit structures at different angles of electromagnetic wave incidence in the equatorial section and the spherical end section is shown.

[0138] Depend on Fig. 11-16 It can be seen that when the linearly polarized feed is incident along the edge of the equatorial section, the refractive indices of the X and Y components remain basically unchanged as the incident angle θ increases. This means that when the feed is incident on the spherical lens along the equatorial section, the electromagnetic waves emitted are all circularly polarized waves regardless of the incident angle.

[0139] As the linearly polarized feed source is incident along the edge of the sphere's end section, the difference in refractive index between the X and Y components decreases as the incident angle β increases. At this time, as the feed source position changes along the sphere's end section, the incident angle β increases, and the emitted electromagnetic wave gradually changes from a circularly polarized wave to an elliptically polarized wave and then to a linearly polarized wave.

[0140] like Fig. 4 and Fig. 6 As shown, the point where the linearly polarized feed source enters from the edge of the equatorial section is the first illumination position; four first illumination positions A, B, C, and D are sequentially spaced around the circumference of the equatorial section of the spherical lens; when the linearly polarized feed source illuminates the spherical lens from any of the first illumination positions in the circumference of the equatorial section, a high-purity circularly polarized plane wave is emitted from the position opposite the sphere.

[0141] like Fig. 17 As shown, when the linearly polarized feed is incident on the equatorial section, the spherical lens antenna can achieve high-gain radiation at different incident angles θ.

[0142] Fig. 18 The axial ratio of the antenna is shown; the axial ratio is an important indicator of the purity of circularly polarized waves. Generally, an axial ratio below 3dB is considered a relatively pure circularly polarized wave. Fig. 18 As shown, between 5.5 and 8.0 GHz, the axial ratio of the antenna is less than 3 dB at different incident angles, proving that the spherical lens antenna in this embodiment can achieve high-purity circularly polarized radiation effect.

[0143] It should be noted that, in Fig. 17-18 In this context, the smaller the axial ratio, the higher the corresponding circular polarization purity.

[0144] like Fig. 5 and Fig. 7 As shown, the point where the linearly polarized feed source enters from the edge of the spherical end section is the second illumination position; four second illumination positions A', B', C', and D' are sequentially spaced around the circumference of the spherical end section of the spherical lens; the linearly polarized feed source sequentially illuminates the spherical lens along the four second illumination positions along the circumference of the spherical end section.

[0145] When irradiated at point A', a high-purity circularly polarized plane wave is emitted from the position opposite the sphere;

[0146] During the process of the linearly polarized feed moving from point A' to point B', the polarization state of the plane wave emitted from the position opposite the sphere transitions from circular polarization to elliptical polarization and then to linear polarization.

[0147] During the process of the linearly polarized feed moving from point B' to point C', the polarization state of the plane wave emitted from the position opposite the sphere transitions from linear polarization to elliptical polarization and then to circular polarization.

[0148] When irradiated at point D', a high-purity circularly polarized plane wave is emitted from the position opposite the sphere;

[0149] like Fig. 19 As shown, when the feed is incident on the end section of the sphere, the lens antenna can achieve high gain radiation at different incident angles β. Fig. 20 The axial ratio of the antenna is given. From 5.5 to 8 GHz, the axial ratio of the antenna increases with the increase of the incident angle β, which proves that the polarization of the spherical lens antenna can be adjusted.

[0150] Example 2

[0151] like Fig. 9-10 As shown, this embodiment also provides a method for manufacturing a spherical lens antenna as described in Embodiment 1. Features not explained in this embodiment can be explained using the methods described in Embodiment 1, and will not be repeated here. The difference between this embodiment and Embodiment 1 is:

[0152] The manufacturing method includes the following steps:

[0153] Step A: Prepare a non-metallic sheet substrate, and arrange the electromagnetic baseband units of the metal thin film material at intervals on the surface of the sheet substrate, so that all axial basebands are arranged in the same direction parallel to the main axis, and all radial basebands are arranged in the same direction perpendicular to the main axis, and arrange the axial baseband length of each electromagnetic baseband unit to be greater than its radial baseband length.

[0154] Step B: Cut multiple sheet substrates to the preset size according to the size of the sphere;

[0155] Step C: Fold or bend the sheet substrate in a direction parallel to the main axis to form multiple bonding beams with alternating concave and convex shapes and multiple cavity grooves. Bond and fix the bonding beams of the multiple sheet substrates from left to right, so that the cavity grooves are connected to each other to form multiple tubular cavities parallel to the main axis.

[0156] Step D: The linearly polarized feed source is positioned along the movement trajectory of the spherical lens from the end of the sphere located at any end of the main axis direction to the equator of the sphere. The linear polarization direction of the electromagnetic wave emitted by the feed source is adjusted and tilted relative to the main axis direction.

[0157] Specifically, the spherical lens is constructed into multiple layers with different refractive indices from the center outwards. The refractive indices are the same within the same layer, and the refractive indices of different layers decrease from the inside out. In step A, the electromagnetic baseband units located in the same refractive layer are arranged as identical units.

[0158] Specifically, the sheet-like substrate is made of aramid paper;

[0159] It should be noted that the honeycomb-shaped three-dimensional support structure of the sphere, made of aramid paper, can be quickly formed through die-cutting. Its interior has a periodically arranged hexagonal cavity structure. This hexagonal cavity structure, combined with the electromagnetic baseband unit attached to the surface, makes the electromagnetic characteristics of the spherical lens exhibit different equivalent dielectric constants for linearly polarized electromagnetic waves along the axial baseband extension direction (i.e., the Y-axis direction) and along the radial baseband extension direction (i.e., the X-axis direction), thus producing different refractive indices. The spherical lens described in this embodiment does not require complex gradient doping or precision processing, is easy to manufacture, has relaxed tolerance requirements, significantly reduces costs, and can shorten the production cycle to 3 days.

[0160] Example 3

[0161] This embodiment also provides a communication base station. Features not explained in this embodiment can be explained using the methods described in Embodiment 1, and will not be repeated here. The difference between this embodiment and Embodiment 1 is as follows:

[0162] The communication base station includes a spherical lens antenna as described in Embodiment 1.

[0163] Example 4

[0164] This embodiment also provides a communication system. Features not explained in this embodiment can be explained using the methods described in Embodiment 3, and will not be repeated here. The difference between this embodiment and Embodiment 3 is as follows:

[0165] The communication system includes a communication base station as described in Embodiment 3.

[0166] Example 5

[0167] This embodiment also provides a communication method for the communication system as described in Embodiment 4. Features not explained in this embodiment can be explained using the methods described in Embodiment 4, and will not be repeated here. The difference between this embodiment and Embodiment 4 is as follows:

[0168] The communication method includes one of the following steps:

[0169] Step H: Control the spherical lens to rotate dynamically relative to the moving trajectory according to a set program, so as to dynamically change the polarization state of the emitted communication electromagnetic wave, and control the communication electromagnetic wave signal receiving end to synchronously adjust the polarization direction of the receiving antenna to match the polarization state of the emitted electromagnetic wave.

[0170] Step 1: Control the linearly polarized feed source to move dynamically along the moving trajectory according to the set program, so as to dynamically change the polarization state or the emission direction of the emitted communication electromagnetic wave, and control the communication electromagnetic wave signal receiving end to synchronously adjust the polarization state or receiving direction of the receiving antenna to match the emitted electromagnetic wave.

[0171] Step J: Configure multiple fixed linearly polarized feed sources along the moving trajectory, control the working state of the linearly polarized feed sources at different positions according to the set program to dynamically change the polarization state of the emitted electromagnetic wave or the radiation coverage range of the electromagnetic wave, and control the communication electromagnetic wave signal receiving end to synchronously adjust the working state of the receiving antenna.

[0172] Specifically, the setup procedure is distributed as a key between the communication base station and the signal receiving end.

[0173] It should be noted that the communication method using step H has a wider range of applications, can improve communication privacy, and prevent the theft of transmitted information. The communication method using step J can increase the scanning coverage of the beam.

[0174] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention.

Claims

1. A spherical lens antenna with adjustable linear polarization to circular polarization for communication electromagnetic waves, comprising a controllable polarization spherical lens and a linear polarization feed, characterized in that: The controllable polarization spherical lens is a sphere made of a non-metallic sheet substrate. The sphere has multiple tubular cavities that extend parallel to the main axis. Multiple electromagnetic baseband units made of metal are arranged on the inner wall of the tubular cavities. The electromagnetic baseband units include an axial baseband that extends parallel to the main axis of the tubular cavity and a radial baseband that is perpendicular to the main axis. A spherical end from either end of the tubular cavity along the main axis is configured with a movement trajectory extending to the equator of the sphere along the outer surface of the sphere, and the linearly polarized feed source is configured on the movement trajectory. The linearly polarized feed source is used to emit polarized electromagnetic waves with the linear polarization direction at an angle to the main axis direction towards the sphere. The axial baseband of the electromagnetic baseband unit is configured to be longer than the radial baseband, so that the refractive index of the electromagnetic wave along the main axis is greater than the refractive index along the radial direction; when the linearly polarized feed source is located at the equator of the moving trajectory, its electromagnetic wave is emitted in circular polarization after being controlled by the spherical lens. Furthermore, when the linearly polarized feed is located at the end of the sphere in the moving trajectory, the polarization direction of its electromagnetic wave remains unchanged after passing through the spherical lens; when the feed is located between the equator and the end of the sphere, its electromagnetic wave is emitted in elliptical polarization after being controlled by the spherical lens. The trajectory of movement includes at least the length from the end of the sphere to the equator of the sphere; The plane formed when the linearly polarized feed surrounds the equator is defined as the equatorial section; the plane formed when the linearly polarized feed surrounds the two ends of the sphere is defined as the end section of the sphere; the end section of the sphere is perpendicular to the equatorial section.

2. The spherical lens antenna according to claim 1, characterized in that, It also includes a drive mechanism for controlling the rotation of the spherical lens. By controlling the spherical lens to rotate along the moving trajectory, the outer surface of the spherical lens and the linearly polarized feed source move relative to each other on the moving trajectory. During the relative movement, the angle between the linear polarization direction of the electromagnetic wave emitted by the linearly polarized feed source and the main axis direction does not change.

3. The spherical lens antenna according to claim 1, characterized in that, It also includes a drive mechanism for controlling the movement of the linearly polarized feed source. By controlling the linearly polarized feed source to move along the moving trajectory, the relative position of the linearly polarized feed source and the outer surface of the spherical lens changes, and the angle between the linear polarization direction of the electromagnetic wave emitted during the movement of the linearly polarized feed source and the main axis remains unchanged.

4. The spherical lens antenna according to claim 1, characterized in that, Multiple fixed linearly polarized feed sources are configured along the moving trajectory, and the linearly polarized feed sources are fixed relative to the spherical lens; Multiple linearly polarized feeds are controlled independently.

5. The spherical lens antenna according to claim 4, characterized in that, It also includes multiple linearly polarized feed sources fixed at the equatorial portion of the spherical lens, the linearly polarized feed sources surrounding the outer periphery of the spherical lens along the equatorial portion, and the feed source surrounding plane being perpendicular to the main axis direction.

6. The spherical lens antenna according to claim 1, characterized in that, The movement trajectory is configured as multiple paths.

7. The spherical lens antenna according to claim 1, characterized in that, The movement trajectory is set on a plane passing through the central axis of the spherical lens.

8. The spherical lens antenna according to claim 1, characterized in that, The tubular cavity extends at both ends along the main axis and penetrates the spherical lens; The cross-sectional shape of the tubular cavity is polygonal or circular.

9. The spherical lens antenna according to claim 1, characterized in that, The tilt angle between the linear polarization direction and the main axis direction of the electromagnetic wave emitted by the linearly polarized feed source is set to 45° in the middle. Let the axial baseband extend in the Y-axis direction, and the radial baseband extend in the X-axis direction; Linearly polarized electromagnetic waves have equal components in the Y and X directions; The refractive index in the Y direction and the refractive index in the X direction conform to the following relationship: ； in, Let X be the refractive index in the X direction. The refractive index is in the Y direction. R is the wavelength of the operating frequency band, R is the radius of the spherical lens, and r is the radial length from the center of the spherical lens.

10. The spherical lens antenna according to claim 9, characterized in that, The electromagnetic wave emitted by the linearly polarized feed source is emitted through the spherical lens. The phase difference between the electromagnetic wave components in the Y and X directions is 90°. The tilt angle between the polarization direction of the electromagnetic wave emitted by the linearly polarized feed source and the main axis direction is set to +45° or -45°, so that the electromagnetic wave refracted by the spherical lens forms a left-hand circular polarization or a right-hand circular polarization emission.

11. The spherical lens antenna according to claim 1, characterized in that, The axial baseband length of the electromagnetic baseband unit near the center of the sphere is configured to be greater than the axial baseband length of the electromagnetic baseband unit far from the center of the sphere, and the radial baseband length of the electromagnetic baseband unit near the center of the sphere is configured to be greater than the radial baseband length of the electromagnetic baseband unit far from the center of the sphere; so that the refractive index of the spherical lens near the center position is greater than the refractive index far from the center position, so that the electromagnetic wave incident as a spherical wave is refracted by the spherical lens into a plane wave and emitted.

12. The spherical lens antenna according to claim 11, characterized in that, The refractive index within the spherical lens gradually decreases radially from the center of the sphere to the surface. The refractive index along the X direction satisfies the following formula: ； in, R is the refractive index in the X direction at the center of the spherical lens; R is the radius of the spherical lens; r is the radial length from the center of the spherical lens. The refractive index along the Y direction satisfies the following formula: ； in, Let be the refractive index in the Y direction at the center of the spherical lens.

13. The spherical lens antenna according to claim 11, characterized in that, The spherical lens includes a first refractive layer, a second refractive layer, a third refractive layer, ... and an Nth refractive layer arranged sequentially from the center of the sphere to the surface of the sphere, and the multiple refractive layers are arranged concentrically, where N is a positive integer; each of the refractive layers contains the electromagnetic baseband unit, and the refractive index between the refractive layers decreases stepwise from the inner layer to the outer layer.

14. The spherical lens antenna according to claim 13, characterized in that, The linear polarization direction of the electromagnetic wave emitted by the linearly polarized feed source is tilted at an angle of 45° relative to the principal axis direction; the axial baseband extends along the Y-axis, and the radial baseband extends along the X-axis; the components of the linearly polarized electromagnetic wave in the Y and X directions are equal; the refractive indices in the Y and X directions of each refractive layer conform to the following relationship: ； in, The refractive index is in the X direction. The refractive index is in the Y direction; The wavelength of the operating frequency band; For the first i Radial thickness of the refractive layer.

15. A method for manufacturing a spherical lens antenna as described in claim 1, characterized in that, Includes the following steps: Step A: Prepare a non-metallic sheet substrate, and arrange the electromagnetic baseband units of the metal thin film material at intervals on the surface of the sheet substrate, so that all axial basebands are arranged in the same direction parallel to the main axis, and all radial basebands are arranged in the same direction perpendicular to the main axis, and arrange the axial baseband length of each electromagnetic baseband unit to be greater than its radial baseband length. Step B: Cut multiple sheet substrates to the preset size according to the size of the sphere; Step C: Fold or bend the sheet substrate in a direction parallel to the main axis to form multiple bonding beams with alternating concave and convex shapes and multiple cavity grooves. Bond and fix the bonding beams of the multiple sheet substrates from left to right, so that the cavity grooves are connected to each other to form multiple tubular cavities parallel to the main axis. Step D: The linearly polarized feed source is positioned along the movement trajectory of the spherical lens from the end of the sphere located at any end of the main axis direction to the equator of the sphere. The linear polarization direction of the electromagnetic wave emitted by the feed source is adjusted and tilted relative to the main axis direction.

16. The method for manufacturing a spherical lens antenna according to claim 15, characterized in that, The spherical lens is constructed into multiple layers with different refractive indices from the center outwards. The refractive index is the same within the same layer, and the refractive index decreases from the inside to the outside of different layers. In step A, the electromagnetic baseband units located in the same refractive layer are arranged as identical units.

17. A communication base station, characterized in that, Including the spherical lens antenna as described in any one of claims 1 to 14.

18. A communication system, characterized in that, Including the communication base station as described in claim 17.

19. A communication method for the communication system as described in claim 18, characterized in that, Includes one of the following steps: Step H: Control the spherical lens to rotate dynamically relative to the moving trajectory according to a set program, so as to dynamically change the polarization state of the emitted communication electromagnetic wave, and control the communication electromagnetic wave signal receiving end to synchronously adjust the polarization direction of the receiving antenna to match the polarization state of the emitted electromagnetic wave. Step 1: Control the linearly polarized feed source to move dynamically along the moving trajectory according to the set program, so as to dynamically change the polarization state or the emission direction of the emitted communication electromagnetic wave, and control the communication electromagnetic wave signal receiving end to synchronously adjust the polarization state or receiving direction of the receiving antenna to match the emitted electromagnetic wave. Step J: Configure multiple fixed linearly polarized feed sources along the moving trajectory, control the working state of the linearly polarized feed sources at different positions according to the set program to dynamically change the polarization state of the emitted electromagnetic wave or the radiation coverage range of the electromagnetic wave, and control the communication electromagnetic wave signal receiving end to synchronously adjust the working state of the receiving antenna.

20. The communication method according to claim 19, characterized in that, The setup procedure is distributed as a key between the communication base station and the signal receiver.

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