阅读说明：本技术 天线 (Antenna with a shield ) 是由 M·R·德加尼·科德诺 Y·勒特斯图 于 2018-08-08 设计创作，主要内容包括：一种折叠透镜天线结构,包括：堆叠部,堆叠部按顺序包括：反射器、介电间隙、以及相比反射器具有更小面积的副反射器板。(A folded lens antenna structure comprising: a stacking portion including, in order: a reflector, a dielectric gap, and a sub-reflector plate having a smaller area than the reflector.)

1. A folded lens antenna structure comprising:

a stack portion including, in order:

a reflector; a dielectric gap; and a sub-reflector plate having a smaller area than the reflector.

2. The folded lens antenna structure of claim 1, wherein the sub-reflector plate is flat.

3. The folded lens antenna structure of claim 1, wherein the secondary reflector plate is curved.

4. The folded lens antenna structure of claim 3, wherein the sub-reflector plate has a concave curvature facing the reflector.

5. The folded lens antenna structure of claim 3, wherein the sub-reflector plate has a convex curvature facing the reflector.

6. The folded lens antenna structure of any preceding claim, wherein the sub-reflector plate comprises a conductive material.

7. The folded lens antenna structure of any preceding claim, wherein the sub-reflector plate is metallic.

8. The folded lens antenna structure of any preceding claim, further comprising a lens adjacent the sub-reflector plate.

9. The folded lens antenna structure of claim 8, wherein the lens has a focal point outside the lens and a focal length approximately three times a height of the stack.

10. The folded lens antenna structure of any of claims 8 or 9, wherein the secondary reflector plate is convex, forming a cassegrain configuration.

11. The folded lens antenna structure of any one of claims 8 or 9, wherein the sub-reflector plate is concave, forming a Gray Golay configuration.

12. The folded lens antenna structure of any of claims 9-12, wherein the sub-reflector plate is an integral part of the lens.

13. The folded lens antenna structure of claim 12, wherein the secondary reflector plate is printed on the lens.

14. The folded lens antenna structure of any one of claims 9 to 13, wherein the lens is provided by a radome.

15. An antenna radome provides an inverse fresnel zone plate lens for a folded lens antenna structure.

Technical Field

Embodiments of the present disclosure relate to antennas and components for antennas.

Background

Point-to-point radio communication may use a parabolic reflector to create a focused beam of electromagnetic radiation. It is well understood that if the source of electromagnetic radiation is placed at the focal point of the parabolic reflector, the parabolic reflector will create a beam of parallel rays of electromagnetic radiation.

Such an antenna can provide high bandwidth because it can be operated on many different frequency bands simultaneously. Such antennas may also operate with any polarization of electromagnetic radiation. However, it is bulky due to the distance of the focal point to the parabolic reflector and the size of the parabolic reflector.

It would be desirable to produce an antenna that is less bulky and operates on multiple frequency bands simultaneously, while operating with dual polarization.

Disclosure of Invention

According to various, but not necessarily all, embodiments there is provided a folded-lens antenna structure comprising: a stacking portion including, in order: a reflector; a dielectric gap; and a sub-reflector plate having a smaller area than the reflector.

In at least some examples, the secondary reflector plate is flat.

In at least some examples, the secondary reflector plate is curved. In at least some examples, the secondary reflector plate has a concave curvature facing the reflector. In at least some examples, the secondary reflector plate has a convex curvature facing the reflector.

In at least some examples, the secondary reflector plate comprises an electrically conductive material.

In at least some examples, the secondary reflector plate is metallic.

In at least some examples, the folded lens antenna structure includes a lens adjacent to the secondary reflector plate.

In at least some examples, the lens has a focal point external to the lens and a focal length approximately three times a height of the stack.

In at least some examples, the secondary reflector plate is convex, forming a cassegrain configuration.

In at least some examples, the secondary reflector plate is concave, forming a Gragolian configuration.

In at least some examples, the secondary reflector plate is an integral part of the lens. In at least some examples, the secondary reflector plate is printed on the lens.

In at least some examples, the lens is provided by a radome.

According to various, but not necessarily all, embodiments, there are provided examples as claimed in the appended claims.

Drawings

Some example embodiments will now be described with reference to the accompanying drawings, in which:

FIG. 1 illustrates an example embodiment of the subject matter described herein;

2A, 2B, 2C each illustrate another example embodiment of the subject matter described herein;

FIGS. 3A, 3B each illustrate another example embodiment of the subject matter described herein;

fig. 4 illustrates another example embodiment of the subject matter described herein.

Detailed Description

Fig. 1 illustrates an example of a folded lens antenna structure 10. The folded lens antenna structure 10 includes a stack portion 20, the stack portion 20 including, in order: reflector 50, dielectric gap 40 and sub-reflector plate 30.

The sub-reflector plate 30 has a smaller area than the reflector 50. The sub-reflector plate 30 will create a shadow. It is therefore preferable to make it small.

The dielectric gap 40 may be an air gap or may comprise other dielectric materials.

The structure 10 is folded in that the electromagnetic radiation 62 takes a zigzag path through the stack 20 before it emerges from the stack 20. Electromagnetic radiation 62 emerging from the stack 20 has been reflected by the sub-reflector plate 30 and also by the reflector 50. Due to the two reflections, the path length for the electromagnetic radiation 62 through the stack 20 is therefore significantly greater than the thickness of the stack 20. This means that a lens 70 having a focal length F, which is significantly larger than the height H of the stack 20, but substantially equal to the zigzag path length L of the electromagnetic radiation 62 passing through the stack 20, may be placed near the stack 20, where F ≈ 3H. The folded lens antenna structure 10 is thus a compact arrangement that enables the use of a lens 70 having a focal length greater than the height of the stack 20. The lens 70 may, for example, be a lens having a focal length approximately three times the height of the stack 20.

The sub-reflector plate 30 is configured to reflect electromagnetic radiation 62. The sub-reflector plate 30 is formed from a continuous layer of conductive material. The conductive material may be metallic, for example.

As illustrated in fig. 2A, in some examples, the sub-reflector plate 30 has a surface 32 facing the reflector 50, the reflector 50 being a flat rectilinear plane.

Alternatively, as illustrated in fig. 2B and 2C, in some examples, the secondary reflector plate 30 has a surface 32 facing the reflector 50, the reflector 50 being curved.

In the example illustrated in fig. 2B, the surface 32 has a concave curvature facing the reflector 50.

In the example illustrated in fig. 2C, the surface 32 has a convex curvature facing the reflector 50.

The reflector 50 is configured to reflect electromagnetic radiation 62. The reflector 50 is formed from a continuous layer of conductive material. The conductive material may be, for example, a metal.

The reflector 50 may be a flat, rectilinear plane or may be curved. For example, the sub-reflector plate 30 may have a convex curvature facing the lens 70.

Folded lens antenna structure 10 may include an aperture 64 within reflector 50, aperture 64 for receiving electromagnetic radiation 62 from source 60. The source 60 may be a waveguide feed or a printed radiating element such as an aperture coupled microstrip patch antenna. The source 60 may be dual polarized and/or multi-frequency.

The bandwidth of the electromagnetic radiation 62 provided by the waveguide feed 60 has a large bandwidth covering at least some or all of the first frequency band F1 and some or all of the second frequency band F2, the second frequency band F2 being separate from the first frequency band F1.

Electromagnetic radiation 62 provided by source 64 is reflected by sub-reflector plate 30 towards reflector 50. The reflected electromagnetic radiation 62 is reflected by the reflector 50 towards the lens 70.

The lens 70 may be any suitable type of lens. Suitable lenses have a focal point external to the lens, and examples include, but are not limited to: fresnel zone plate lenses, hemispherical lenses, printed discrete lenses (transmissive arrays), graded index lenses, subwavelength structured lenses, hemispherical lenses, hyperbolic lenses, and the like. For example, the lens may be a Fresnel lens, such as a folded Fresnel lens or a Fresnel zone plate lens.

In some, but not necessarily all examples, the sub-reflector plate 30 has a concave curvature facing the reflector 50. The combination of the secondary reflector plate 30, the reflector 50 and the lens 70 creates a Cassegrain (Cassegrain) configuration in which the secondary reflector plate 30 operates as a convex Cassegrain secondary reflector and the reflector 50 and lens 70 are configured to simulate a concave parabolic Cassegrain primary reflector. The lens 70 is then designed to operate as a suitable phase correction aperture.

In some, but not necessarily all examples, the sub-reflector plate 30 has a convex curvature facing the reflector 50. The combination of the sub-reflector plate 30, the reflector 50 and the lens 70 creates a Gregorian configuration in which the sub-reflector plate 30 operates as a concave Gregorian sub-reflector and the reflector 50 and the lens 70 are configured to simulate a concave parabolic Gregorian main reflector. The lens 70 is then designed to operate as a suitable phase correction aperture.

The sub-reflector plate 30 may be formed on the lower surface of the lens 70 such that it is an integral part of the lens 70.

In some, but not necessarily all examples, the secondary reflector plate 30 is printed onto the lower surface 72 of the lens 70 such that it is an integral part of the lens 70.

The lens 70 may be a fresnel zone plate lens in some examples, for example, as illustrated in fig. 3A. In this example, a separate radome 80 is used as a protective cover for the lens 70.

In other examples, the lens 70 may be an inverted fresnel zone plate lens, e.g., as illustrated in fig. 3B. The term "inverted" means inverted. In this example, but not necessarily all, the inverted fresnel zone plate lens 70 is formed as an integral part of the radome cover 80. The lens 70 acts as an outer protective cover 80.

Fig. 4 illustrates an example of a base station 200 for a cell of a cellular communication system. The base station 200 includes a backhaul radio frequency transceiver system 202, the backhaul radio frequency transceiver system 202 including the multi-frequency folded lens antenna structure 10 for point-to-point communications. The radio frequency transceiver system 202 is configured in this example to operate at frequencies in excess of 20GHz with dual polarization. It operates at high gain (>30dBi) and has a large bandwidth (20%).

Where structural features have been described, the structural features may be replaced by means for performing one or more of the functions of the structural features, whether the function or those functions are explicitly described or implicitly described.

The term "comprising" is used herein in an inclusive rather than exclusive sense. That is, any reference to X including Y indicates that X may include only one Y or may include more than one Y. If it is intended to use "including" in an exclusive sense, it will be clear from the context by reference to "including only one" or by use of "consisting of … ….

In this description, reference has been made to various examples. The description of features or functions with respect to the examples indicates the presence of such features or functions in the examples. Whether or not explicitly stated, the terms "example" or "e.g.," or "may" are used herein to indicate that such features or functions are present in at least the described examples, whether described as examples or not, and that they may, but are not necessarily, present in some or all of the other examples. Thus, "examples," e.g., "may" or "may" refer to particular instances of a class of examples. The property of an instance may be a property of only that instance, or a property of the class, or a property of a subclass of the class that includes some, but not all, instances in the class. Thus, it is implicitly disclosed that features described with reference to one example, but not with reference to another example, may be used as part of a working combination in this other example where possible, but do not necessarily have to be used in this other example.

Although embodiments have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the claims.

Features described in the foregoing description may be used in combinations other than those explicitly described above.

Although functions have been described with reference to certain features, those functions may be performed by other features, whether described or not.

Although features have been described with reference to certain embodiments, those features may also be present in other embodiments, whether described or not.

The terms "a" and "an" or "the" are used herein in an inclusive rather than exclusive sense. That is, any reference to X including a/the Y indicates that X may include only one Y or may include more than one Y unless the context clearly dictates otherwise. If the intention is to use "a" or "the" in an exclusive sense, it will be clear from the context. In some cases, the use of "at least one" or "one or more" may be used to emphasize an inclusive meaning, but the absence of such terms should not be used to infer an exclusive meaning.

The presence of a feature (or a combination of features) in a claim is a reference to that feature (or combination of features) itself and also to features that achieve substantially the same technical effect (equivalent features). Equivalent features include, for example, features that are variants and achieve substantially the same result in substantially the same way. Equivalent features include, for example, features that perform substantially the same function in substantially the same way to achieve substantially the same result.

In this description, adjectives or adjective phrases have been used to describe characteristics of examples to reference various examples. This description of example-related features indicates that the features exist exactly as described in some examples, and substantially as described in other examples.

Whether or not explicitly stated, the terms "example" or "e.g.," or "may" are used herein to indicate that such features or functions are present in at least the described examples, whether described as examples or not, and that they may, but are not necessarily, present in some or all of the other examples. Thus, "examples," e.g., "may" or "may" refer to particular instances of a class of examples. The property of an instance may be a property of only that instance, or a property of the class, or a property of a subclass of the class that includes some, but not all, instances in the class. Thus, it is implicitly disclosed that features described with reference to one example, but not with reference to another example, may be used as part of a working combination in this other example where possible, but do not necessarily have to be used in this other example.

Whilst endeavoring in the foregoing specification to draw attention to those features believed to be of importance it should be understood that the applicant may seek protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.