Light-weight paper-based reflecting lens for electromagnetic wave beam modulation and planar reflecting antenna of light-weight paper-based reflecting lens

Abstract

The invention discloses a light paper-based reflection lens for electromagnetic wave beam modulation and a planar reflection antenna thereof, and belongs to the technical field of antennas. The reflecting lens comprises a paper-based main body, the paper base main body is formed by forming a hole structure which is surrounded by a sheet-shaped paper base and is periodically arranged at intervals, and the paper base main body is provided with an upper surface and a lower surface which are opposite to each other and are respectively an electromagnetic wave control surface and a reflection plane; film-shaped symbol units made of metal materials are distributed and attached to the sheet-shaped paper base; the planar reflection antenna further comprises a feed source. The feed source is close to and inversely installed on the control surface, and the feed source reciprocates along the track of the control surface. An electromagnetic wave reflecting plate is arranged on the surface of the reflecting plane. The feed source can be placed at any position of the control surface, and electromagnetic waves emitted by the feed source at any position can be spread out of the reflection lens in a plane wave form after passing through the plane reflection antenna. Moreover, the bandwidth of wide-angle scanning realized by the plane reflecting antenna can reach 80%, which is far wider than that of the traditional reflecting surface antenna.

Description

Technical Field

[0001] The invention belongs to the technical field of antennas, and in particular relates to a lightweight paper-based reflecting lens and a planar reflecting antenna thereof for electromagnetic wave beam modulation. Background Art

[0002] With the rapid development of the new generation of mobile communication technology (B5G / 6G), there is an urgent need for antennas with large bandwidth, high gain, and wide angle scanning. As a form of high-gain antenna, the main advantages of reflective large-aperture antennas are high gain, high efficiency, and no need for a feeding network. In recent years, they have attracted widespread attention from academia and industry. At present, there are two main forms of classic large-aperture reflective antennas: parabolic antennas and reflector antennas.

[0003] Among them, the traditional parabolic antenna uses a curved surface structure to convert the spherical wave at the focus into a high-gain plane wave. When transmitting, the signal radiates from the feed source to the parabola, and then radiates into the air after being reflected by the parabola. As in the prior art, a Chinese patent with publication number CN1152196A discloses a parabolic antenna, wherein the parabolic antenna includes a reflector, a horn-shaped feed source, a frame with one end fixed to the rear side of the reflector, a cantilever with the horn-shaped feed source fixed at one end, a pair of hinges, a boss and an axis, so that the horn-shaped feed source can be easily set at the focus of the reflector. Figure 1 As shown, since the feed source is located at the focus of the parabola, the electromagnetic wave will radiate parallel to the normal direction of the parabola after being reflected by the parabola.

[0004] The reflector antenna uses the resonant structure on the aperture surface to phase the electromagnetic waves reaching the surface, such as Figure 1 As shown. In the prior art, a Chinese patent with publication number CN107634339B discloses a highly directional umbrella-shaped convex conformal reflector antenna based on a metasurface, which includes an umbrella-shaped convex carrier, an umbrella-shaped convex mirror, a feed source, a coaxial conversion joint and a supporting structure. The umbrella-shaped convex mirror is composed of a planar polygonal discrete metasurface with even-numbered regular n-gons and m×n planar isosceles trapezoidal discrete metasurfaces, which are inlaid on the convex surface of the umbrella-shaped convex carrier. The planar polygonal discrete metasurface and the planar isosceles trapezoidal discrete metasurface both include a dielectric substrate, a radiation floor and a resonant ring metasurface. The resonant ring metasurface is composed of resonant rings of different specifications and periodically arranged in two-dimensional linear patterns, and each resonant ring provides phase compensation for the incident wave. This prior art mainly solves the problem that the convex mirror conformal to the umbrella-shaped convex carrier cannot achieve beam calibration, but due to the use of a resonant structure, the working bandwidth of the reflector antenna will be narrowed.

[0005] In addition, if Figure 1As shown, both the parabola and the reflector have the same disadvantage: the feed must be placed directly above the center of the parabola / reflector. Once the feed deviates from the focus, the gain of the antenna will drop sharply and the beam scanning angle of the antenna will also become smaller.

[0006] Therefore, how to realize a broadband, large-angle scanning, and high-gain reflective antenna is a major technical difficulty and defect in this field. Summary of the invention

[0007] In view of the problems in the related art, the present invention proposes a lightweight paper-based reflective lens and a planar reflective antenna for electromagnetic wave beam modulation to overcome the above-mentioned technical problems existing in the existing related art. The lightweight paper-based reflective lens of the present invention includes a paper-based main body, which is formed by a sheet-like paper base surrounding a periodically arranged hole structure, and has two opposing upper and lower surfaces, which are respectively a control surface and a reflection plane of the electromagnetic wave; the sheet-like paper base is distributed with symbol units of a thin film of metal material; an electromagnetic wave reflection plate is provided on the surface of the reflection plane; a feed source is close to and inverted on the control surface; the electromagnetic wave is reflected and propagated in the reflective lens in a curved path, and is collimated and emitted to the outside of the reflective lens; the electromagnetic waves emitted by different feed sources on the focal plane have a gain roll-off of less than 2dB after being radiated by the planar reflective antenna.

[0008] The technical solution of the present invention is implemented as follows: a lightweight paper-based reflective lens for electromagnetic wave beam modulation, comprising a paper-based main body, wherein the paper-based main body is formed by a sheet-like paper base surrounding a periodically spaced cavity structure, and has an upper and a lower opposing surface, which are respectively a control surface and a reflection plane of the electromagnetic wave;

[0009] The sheet-like paper base is distributed with symbol units made of thin-film metal material;

[0010] Furthermore, the attachment method of the symbol unit includes but is not limited to printing and pasting;

[0011] It should be noted that: the symbol unit is attached to the surface of the sheet-like paper base, or the symbol unit is arranged inside the sheet-like paper base, which also has the same technical effect;

[0012] The symbol unit, comparing the metal surface area of ​​the symbol unit per unit volume in the paper base body, the metal surface area per unit volume in the middle of the paper base body is greater than that in the periphery of the paper base body;

[0013] The reflective plane has an electromagnetic wave reflective plate disposed on its surface.

[0014] Furthermore, the control surface is a plane and is arranged parallel to the reflection plane;

[0015] The paper base body is cylindrical, polygonal or frustum-shaped;

[0016] The cavity structure is a circular or polygonal three-dimensional columnar cavity structure.

[0017] Furthermore, at the position where the metal surface area per unit volume is the largest, the metal surface area gradually decreases in the radial direction toward the circumferential side; or decreases in steps; or decreases periodically;

[0018] It should be noted that the step reduction means that the reduction of the metal surface area is not a continuous and smooth decline, but in the process of decline, some obvious turning points or plateaus may appear, so that the decline speed slows down or pauses near these points, thus forming a step-like shape;

[0019] The periodic reduction means that during the reduction of the metal surface area, its value shows a periodic downward trend. This periodic change usually means that within a fixed time interval, the value of the curve will experience a complete rise and fall process, and this process will be repeated to form periodic fluctuations.

[0020] Furthermore, the electromagnetic wave refractive index at the unit volume position where the metal surface area is the largest is set to n0, the height between the upper and lower opposing surfaces of the paper base body is set to w, and the radial distance extending circumferentially with n0 as the center is set to r, then the refractive index n(r) at the position r conforms to the following inverse hyperbolic cosine distribution law:

[0021] n(r)=n0sech(πr / (4w));

[0022] It should be noted that the larger the metal surface area, the larger the value of n0, and the larger the final refractive index n(r); but in practical applications, the value range of n0 is generally between 1 and 3, and a higher n0 is also possible, but the specific implementation will be relatively difficult.

[0023] Further, the symbol unit is arranged on the side wall surrounding and facing the cavity structure, and the unit volume covers at least one cavity structure in the plane direction and contains at least one symbol unit in the vertical direction; in the present invention, it means that at least one cavity structure is included on the horizontal plane of the reflective lens, and at least one symbol unit is included on the vertical plane perpendicular to the horizontal plane;

[0024] At least one of the arrangement density, size, and shape of the symbol units in part of the hole structure is different from that in another part of the hole structure; it should be noted that within the same paper base body, the symbol units with different hole structures are different; in the present invention, different equivalent dielectric constants can be obtained by adjusting the symbol units.

[0025] Furthermore, the material of the paper base includes aramid paper.

[0026] Furthermore, the electromagnetic wave reflection plate is made of metal.

[0027] Furthermore, the paper base includes but is not limited to being made of aramid paper or a flexible PCB board, and the symbol unit is fixed on the aramid paper or the flexible PCB board by printing or attaching.

[0028] Furthermore, the shape of the symbol unit includes an open ring, a cross, or a circular ring.

[0029] Furthermore, the size of the equivalent dielectric constant is changed by adjusting the length of each side of each of the symbol units.

[0030] Furthermore, the side length is positively correlated with the equivalent dielectric constant, that is, the larger the side length, the higher the equivalent dielectric constant;

[0031] Furthermore, the value range of the equivalent dielectric constant is 1-2.

[0032] The symbol unit is made of metal material with high conductivity.

[0033] A planar reflective antenna for wide angle and high gain, comprising the above-mentioned reflective lens; and

[0034] The feed source is close to and inverted on the control surface, and the control surface is a plane; the electromagnetic wave is reflected and propagated in the reflection lens along a curved path, and is collimated and emitted outside the reflection lens.

[0035] Furthermore, the feed source is a mobile feed source, and the moving track extends along a straight line or a plane direction and corresponds to the control surface; so that a single mobile feed source can achieve a scanning technical effect;

[0036] Or, the feed source is a fixed feed source, having multiple feed sources, arranged along a straight line or a plane direction, and corresponding to the control surface; the present invention realizes the multi-beam effect by setting multiple feed sources at the same time, wherein one feed source corresponds to one beam; under the condition of multiple beams, multiple electromagnetic waves at different angles will be emitted in the form of plane waves in different directions after being emitted;

[0037] Furthermore, the output surfaces of the electromagnetic waves of the multiple feed sources are located at the same height.

[0038] Furthermore, the focal plane of the reflective lens is set to coincide with the control surface, and the feed source is installed close to the surface of the paper-based body;

[0039] It should be noted that: a conventional antenna generally has only one central focus, and the feed source needs to be placed at the central focus, extending along the central focus position and perpendicular to the optical axis to form a plane. If the feed source is placed at a position on this plane that deviates from the central focus, the convergence effect of the electromagnetic waves emitted by the feed source will be poor; however, the entire incident plane of the reflective lens of the present invention is the focal plane, and the refraction effect of the electromagnetic waves emitted by the feed source at any position on the focal plane is basically the same. The present invention will not cause the problem of a sharp drop in antenna gain and a decrease in the antenna beam scanning angle;

[0040] Moreover, in the prior art, the feed source of the parabolic antenna and the reflector antenna must be suspended at the central focus, and the suspension installation is difficult. However, the feed source of the reflective lens described in the present invention is directly installed along the plane, and the plane installation is simpler and more convenient than the suspension installation. Therefore, compared with the existing parabolic antenna and reflector antenna, the plane reflective antenna of the present invention is easier to install the feed source.

[0041] The gain roll-off of the electromagnetic wave emitted by the feed source at any position on the focal plane after being radiated by the reflective lens is less than 2 dB.

[0042] Furthermore, the antenna aperture surface refers to the cross section of the planar reflection antenna, and the control surface is the antenna aperture surface that outputs electromagnetic waves.

[0043] Beneficial effects of the present invention:

[0044] The present invention discloses a lightweight paper-based reflective lens and a plane reflective antenna for electromagnetic wave beam modulation. The reflective lens includes a paper-based main body, which is formed by a sheet-like paper base surrounding a periodically spaced hole structure, and has two opposing upper and lower surfaces, which are respectively a control surface and a reflection plane of electromagnetic waves; the sheet-like paper base is distributed with thin-film metal material symbol units; the feed source is close to and inverted on the control surface, and the feed source moves back and forth along the control surface trajectory. An electromagnetic wave reflector is provided on the surface of the reflection plane. In the present invention, the feed source can be placed at any position on the control surface, and the electromagnetic waves emitted by the feed source at any position can be propagated to the outside of the reflective lens in the form of plane waves after passing through the plane reflective antenna.

[0045] Moreover, compared with parabolic antennas and reflector antennas, the biggest advantage of the present invention is that when the feed source moves, the present invention can achieve wide-angle scanning of the beam. Within the scanning range of ±50 degrees, the gain roll-off of the planar reflector antenna described in the present invention is less than 2dB, and very high gain and aperture efficiency can be achieved; at the same time, the present invention can also achieve a multi-beam effect.

[0046] In addition, the bandwidth of the wide-angle scanning achieved by the planar reflective antenna of the present invention can reach 80%, which is much wider than that of the traditional reflective antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 A schematic diagram of electromagnetic wave propagation paths of existing parabolic antennas and reflector antennas;

[0048] Figure 2 It is a schematic diagram of the radial decrease of the refractive index on the aperture surface of the antenna of the present invention;

[0049] Figure 3 A schematic diagram of the electromagnetic wave propagation path when the feed source of the present invention is at different positions on the antenna aperture plane;

[0050] Figure 4 It is a schematic diagram of the structure of the symbol unit printed on aramid paper of the present invention;

[0051] Figure 5 It is a top view of the planar reflective antenna using the paper-based main body as a carrier of the present invention;

[0052] Figure 6 It is a side view of the planar reflective antenna with a paper-based main body as a carrier of the present invention;

[0053] Figure 7 It is a schematic diagram of the three-dimensional structure of the planar reflective antenna based on the reflective lens of the present invention;

[0054] Figure 8 A schematic diagram of the position of the feed source of the present invention moving on the antenna aperture plane;

[0055] Fig. 9 It is a curve diagram of the antenna beam scanning angle and gain change when the position of the feed source of the present invention moves;

[0056] Fig.10 It is a schematic diagram of the curve of the gain at different scanning angles changing with frequency according to the present invention. DETAILED DESCRIPTION

[0057] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0059] Example 1

[0060] like Figure 1-10 As shown, this embodiment provides a light-weight paper-based reflective lens for electromagnetic wave beam modulation, comprising a paper-based main body,

[0061] The paper base body is formed by a sheet of paper base surrounding a periodically spaced hole structure, and has two opposing upper and lower surfaces, which are respectively a control surface and a reflection surface of electromagnetic waves;

[0062] The sheet-like paper base is distributed with symbol units made of thin-film metal material;

[0063] Specifically, the attachment method of the symbol unit includes but is not limited to printing and pasting;

[0064] It should be noted that: the symbol unit is attached to the surface of the sheet-like paper base, or the symbol unit is arranged inside the sheet-like paper base, which also has the same technical effect;

[0065] The symbol unit, comparing the metal surface area of ​​the symbol unit per unit volume in the paper base body, the metal surface area per unit volume in the middle of the paper base body is greater than the periphery of the paper base body; so that the refractive index of the middle position of the reflective lens is greater than the refractive index of the periphery, such as Figure 2 As shown;

[0066] The reflective plane has an electromagnetic wave reflective plate disposed on its surface.

[0067] Specifically, the control surface is a plane and is arranged parallel to the reflection plane;

[0068] The paper base body is cylindrical, polygonal or frustum-shaped;

[0069] It should be noted that this embodiment does not limit the shape of the paper-based body. In addition to being cylindrical, it can also be any other three-dimensional structure. In this embodiment, a cylindrical shape is preferred. The advantage of using a cylindrical shape is that the power of the electromagnetic waves radiated from the reflective lens can be symmetrical in all directions.

[0070] Specifically, the electromagnetic wave reflection plate is made of metal, and is mainly used to reflect electromagnetic waves transmitted to the electromagnetic wave reflection plate; in this embodiment, the electromagnetic wave reflection plate includes but is not limited to being made of aluminum plate and copper plate.

[0071] Specifically, at the position where the metal surface area per unit volume is the largest, the metal surface area gradually decreases in the radial direction toward the circumferential side; or decreases in steps; or decreases periodically;

[0072] It should be noted that the step reduction means that the reduction of the metal surface area is not a continuous and smooth decline, but in the process of decline, some obvious turning points or plateaus may appear, so that the decline speed slows down or pauses near these points, thus forming a step-like shape;

[0073] The periodic reduction means that during the reduction of the metal surface area, its value shows a periodic downward trend. This periodic change usually means that within a fixed time interval, the value of the curve will experience a complete rise and fall process, and this process will be repeated to form periodic fluctuations.

[0074] Specifically, the antenna aperture surface refers to the cross section of the planar reflection antenna, and the control surface is the antenna aperture surface that outputs electromagnetic waves;

[0075] In order to achieve a large beam scanning angle when the subsequent feed source moves on the antenna aperture plane, while ensuring that the gain does not drop significantly, a gradient refractive index is constructed on the antenna aperture plane, such as Figure 2 As shown;

[0076] More specifically, the electromagnetic wave refractive index per unit volume position of the largest metal surface area is set as n0, the height between the upper and lower opposing surfaces of the paper base body is set as w, and the radial distance extending circumferentially with n0 as the center is set as r, then the refractive index n(r) at position r conforms to the following inverse hyperbolic cosine distribution law:

[0077] n(r)=n0sech(πr / (4w));

[0078] It should be noted that the larger the metal surface area, the larger the value of n0, and the larger the final refractive index n(r); but in practical applications, the value range of n0 is generally between 1 and 3, and a higher n0 is also possible, but the specific implementation will be relatively difficult.

[0079] According to the above formula, the refractive index corresponding to each point on the antenna aperture surface can be obtained by calculation. The refractive index distribution on the antenna aperture surface is as follows: Figure 2As shown, the refractive index at the center of the antenna aperture surface is the highest, and the refractive index gradually decreases from the center along the surrounding edges.

[0080] Specifically, the symbol unit is arranged on the side wall surrounding and facing the cavity structure, and the unit volume covers at least one cavity structure in the plane direction and contains at least one symbol unit in the vertical direction; in this embodiment, it means that at least one cavity structure is included on the horizontal plane of the reflective lens, and at least one symbol unit is included on the vertical plane perpendicular to the horizontal plane;

[0081] At least one of the arrangement density, size, and shape of the symbol units in part of the hole structure is different from that in another part of the hole structure; it should be noted that within the same paper base body, the symbol units with different hole structures are different; in this embodiment, different equivalent dielectric constants can be obtained by adjusting the symbol units.

[0082] Specifically, the material of the paper base includes aramid paper;

[0083] More specifically, the paper base includes but is not limited to being made of aramid paper or a flexible PCB board, and the symbol unit is fixed on the aramid paper or the flexible PCB board by printing or attaching;

[0084] It should be noted that: in the reflective lens, the paper-based body mainly plays a supporting role, and the paper-based body made of aramid paper used in this embodiment has a unique spatial structure and mechanical properties; moreover, aramid paper has excellent chemical inertness and can immediately self-extinguish when away from the fire source, and has good heat insulation, temperature resistance, electrical insulation and electromagnetic wave transmission properties;

[0085] The cavity structure is a circular or polygonal three-dimensional columnar cavity structure;

[0086] In this embodiment, the hole structure can specifically be a hexagonal three-dimensional columnar void structure; the hexagonal three-dimensional columnar void structure makes the paper base body have better axial compression and impact resistance, and has excellent sound insulation and fatigue resistance, and also makes the reflective lens have a lower density, so the overall mass is lighter than other materials; moreover, the hole structure is arranged in a hexagonal shape, so that subsequent electromagnetic waves can be radiated in the form of plane waves, which can not only achieve large-angle radiation, but also ensure that the gain will not decrease significantly.

[0087] In this embodiment, in order to achieve an equivalent gradient refractive index, a symbol unit is firstly arranged on a sheet-like paper base, and then the size of the symbol unit is adjusted to achieve different equivalent refractive indices;

[0088] It should be noted that the medium in the cavity structure is air, and the dielectric constant of air is 1.0, while the dielectric constant of the paper base body is different from the dielectric constant of air. When the equivalent dielectric constant of the reflective lens is to be increased, the size of the final equivalent dielectric constant can be changed by adjusting the length of each side of the symbol unit.

[0089] Specifically, the shape of the symbol unit includes but is not limited to an open ring, a cross, or a circular ring;

[0090] When the shape of the symbol unit is an open ring, the size of the equivalent dielectric constant is changed by adjusting the length of each side of the open ring; wherein the length of the side is positively correlated with the size of the equivalent dielectric constant, that is, the larger the length of the side, the higher the equivalent dielectric constant;

[0091] More specifically, the value range of the equivalent dielectric constant is 1-2;

[0092] like Figure 5 As shown, in this embodiment, the equivalent dielectric constant is changed by printing an open ring structure on aramid paper, wherein the change of the equivalent dielectric constant is mainly achieved by adjusting the length of each side of the open ring;

[0093] It should be noted that: this embodiment is simulated by electromagnetic simulation software; according to the theory and simulation results, when the area ratio of the symbol unit and the single side wall of the hole structure is the same, no matter how the shape, density, etc. of the symbol unit changes, the equivalent dielectric constant finally achieved is similar.

[0094] The symbol unit is made of a metal material with high conductivity, specifically silver paste, copper, etc. In this embodiment, silver paste is preferably used.

[0095] This embodiment also provides a planar reflective antenna for wide angle and high gain, comprising the above-mentioned reflective lens; and,

[0096] A feed source is close to and inverted on the control surface, and the control surface is a plane; the electromagnetic wave is reflected and propagated in the reflective lens along a curved path, and is collimated and emitted outside the reflective lens;

[0097] like Figure 3 As shown, in the planar reflection antenna, the electromagnetic waves incident on the reflection plane are reflected and then converge toward the control surface in a curved path, and finally emitted to the outside of the reflection lens in the form of a plane wave.

[0098] The feed source is a mobile feed source, and the moving track extends along a straight line or a plane direction and corresponds to the control surface; so that a single mobile feed source can achieve a scanning technical effect;

[0099] Or, the feed source is a fixed feed source, having multiple feed sources, arranged along a straight line or a plane direction, and corresponding to the control surface; this embodiment achieves a multi-beam effect by setting multiple feed sources at the same time, wherein one feed source corresponds to one beam; under the condition of multiple beams, multiple electromagnetic waves at different angles will be emitted in the form of plane waves in different directions after being emitted;

[0100] More specifically, the output surfaces of the electromagnetic waves of the plurality of feed sources are located at the same height.

[0101] Specifically, the focal plane of the reflective lens is set to coincide with the control surface, and the feed source is installed close to the surface of the paper-based body to ensure that a large-angle radiation of electromagnetic waves and a high gain of the antenna can be achieved later;

[0102] It should be noted that: a conventional antenna generally has only one central focus, and the feed source needs to be placed at the central focus, extending along the central focus position and perpendicular to the optical axis to form a plane. If the feed source is placed at a position on this plane that deviates from the central focus, the convergence effect of the electromagnetic waves emitted by the feed source will be poor; however, the entire incident plane of the reflective lens described in this embodiment is the focal plane, and the refraction effect of the electromagnetic waves emitted by the feed source at any position on the focal plane is basically the same. In this embodiment, the problem of a sharp drop in antenna gain and a decrease in the antenna beam scanning angle will not occur;

[0103] like Figure 8-9 As shown, no matter where the feed source is installed on the control surface, the beam scanning angle of the planar antenna changes, and the gain will also change accordingly; Fig. 9 Taking the feed source 3 in the figure as an example, as the beam scanning angle of the reflective lens changes from 0 degree to ±50 degrees, the gain also decreases periodically from 20 dBi;

[0104] More specifically, the gain roll-off of the electromagnetic wave emitted by the feed source at any position on the focal plane after being radiated by the reflective lens is less than 2 dB; wherein the gain roll-off refers to the gain of different beams compared to the maximum gain of all beams;

[0105] like Fig.10 As shown in Figure 1, the gain of different beam scanning angles varies with the frequency, but in the wide frequency range of 1.8 GHz to 3.8 GHz, the gain drop of different beam scanning angles is within 2 dB. Fig.10 Taking the beam scanning angle of 0 degree in as an example, when the frequency changes from 2.0GHz to 2.1GHz, the gain decrease is significantly less than 2dB.

[0106] Moreover, in the prior art, the feed of the parabolic antenna and the reflector antenna must be suspended at the central focus, and the installation of the suspension is difficult, while the feed of the reflective lens described in this embodiment is directly installed along the plane, and the plane installation is simpler and more convenient than the suspension installation. Therefore, compared with the existing parabolic antenna and reflector antenna, the plane reflective antenna of this embodiment is easier to install the feed. In this embodiment, whether aramid paper or flexible PCB board is used, under the condition of the same volume, the weight of both is much lighter than the weight of ceramics, which is conducive to reducing the transportation cost of the plane reflective antenna; and for manufacturers, the larger the volume of the antenna, the higher the processing cost of ceramics, but the processing cost of aramid paper is lower than that of ceramics, so the plane reflective antenna described in this embodiment is also conducive to large-scale production.

[0107] like Figure 3 As shown, this embodiment shows the propagation path of electromagnetic waves inside the reflective lens. Different from parabolic antennas and reflective antennas, due to the presence of the paper-based body, the symbol unit and the electromagnetic wave reflector, after the feed source emits electromagnetic waves from different positions, the electromagnetic waves reach the reflection plane in the form of a curve and are then reflected by the electromagnetic wave reflector. The reflected electromagnetic waves reach the antenna aperture surface and propagate to the free space in the form of a plane wave. Therefore, by placing the feed source at different positions on the control surface, the electromagnetic waves can be radiated in the form of a plane wave, thereby achieving large-angle radiation and preventing a significant decrease in gain.

[0108] Moreover, the bandwidth of the wide-angle scanning achieved by the planar reflection antenna in this embodiment can reach 80%, which is much wider than the bandwidth of the traditional planar transmission antenna.

[0109] Example 2

[0110] This embodiment further provides a light-weight paper-based reflective lens for electromagnetic wave beam modulation. The features not explained in this embodiment can be explained in Example 1, and will not be described in detail here. The difference between this embodiment and Example 1 is:

[0111] The paper base is replaced by a plastic material.

[0112] According to the disclosure and teaching of the above description, those skilled in the art to which the present invention belongs may also 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 scope of protection of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the present invention.

Claims

1. A light paper-based reflective lens for electromagnetic wave beam modulation, comprising a paper-based main body, characterized in that: The paper base body is formed by a sheet of paper base surrounding a periodically spaced hole structure, and has two opposing upper and lower surfaces, which are respectively a control surface and a reflection surface of electromagnetic waves; The sheet-like paper base is distributed with symbol units made of thin-film metal material; The symbol unit, comparing the metal surface area of ​​the symbol unit per unit volume in the paper base body, the metal surface area per unit volume in the middle of the paper base body is greater than that in the periphery of the paper base body; The reflective plane has an electromagnetic wave reflective plate disposed on its surface.

2. The lightweight paper-based reflective lens for electromagnetic wave beam modulation according to claim 1, characterized in that: The control surface is a plane and is arranged parallel to the reflection plane; The paper base body is cylindrical, polygonal or frustum-shaped; The cavity structure is a circular or polygonal three-dimensional columnar cavity structure.

3. The lightweight paper-based reflective lens for electromagnetic wave beam modulation according to claim 1, characterized in that: At the position where the metal surface area per unit volume is the largest, the metal surface area gradually decreases along the radial direction toward the circumferential side; or decreases in steps; or decreases periodically.

4. The lightweight paper-based reflective lens for electromagnetic wave beam modulation according to claim 1 or 3, characterized in that: The electromagnetic wave refractive index per unit volume position of the largest metal surface area is set as n0, the height between the upper and lower opposing surfaces of the paper base body is set as w, and the radial distance extending along the circumferential direction with n0 as the center is set as r, then the refractive index n(r) at the position r conforms to the following inverse hyperbolic cosine distribution law: n(r)=n0sech(πr / (4w)).

5. The lightweight paper-based reflective lens for electromagnetic wave beam modulation according to claim 1 or 2, characterized in that: The symbol unit is arranged on a side wall surrounding and facing the cavity structure, the unit volume covers at least one cavity structure in the planar direction and contains at least one symbol unit in the vertical direction; At least one of the arrangement density, size, and shape of the symbol units in a portion of the hole structures is different from that in another portion of the hole structures.

6. The lightweight paper-based reflective lens for electromagnetic wave beam modulation according to claim 1, characterized in that: The material of the paper base includes aramid paper.

7. The lightweight paper-based reflective lens for electromagnetic wave beam modulation according to claim 1, characterized in that: The electromagnetic wave reflection plate is made of metal.

8. A planar reflective antenna for wide angle and high gain, characterized in that: comprising the reflective lens according to any one of claims 1 to 7; and The feed source is close to and inverted on the control surface, and the control surface is a plane; the electromagnetic wave is reflected and propagated in the reflection lens along a curved path, and is collimated and emitted outside the reflection lens.

9. The planar reflective antenna according to claim 8, characterized in that: The feed source is a mobile feed source, and its moving trajectory extends along a straight line or a planar direction and corresponds to the control surface; or, the feed source is a fixed feed source, having multiple feed sources, arranged along a straight line or a planar direction, and corresponding to the control surface.

10. The planar reflective antenna according to claim 8, characterized in that: The focal plane of the reflective lens is set to coincide with the control surface, and the feed source is installed close to the surface of the paper-based body; The gain roll-off of the electromagnetic wave emitted by the feed source at any position on the focal plane after being radiated by the reflective lens is less than 2 dB.

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