Antenna assembly with adjustable gain lens

Abstract

An antenna assembly having an adjustable gain lens, the adjustable gain antenna including an RF transmitter configured to transmit an RF signal along a transmitter axis. The first refractive lens has an optical axis collinear with the emitter axis and the second refractive lens has an optical axis collinear with the emitter axis, wherein the first refractive lens is located between the RF emitter and the second refractive lens. A drive mechanism is mechanically linked to the first and second refractive lenses, wherein the drive mechanism is configured to move the first and second refractive lenses longitudinally along the transmitter axis to vary the gain of the RF transmitter.

Description

Technical Field

[0001] The present disclosure relates to the field of antennas, and in particular to radio frequency (RF) antennas with adjustable gain. Background Art

[0002] Antennas typically include a transmitter having at least one focusing element that directs electromagnetic radiation in a direction of interest. The size, shape, and longitudinal position of the focusing element along the transmitter axis contribute to the gain that the antenna can produce. Typically, an antenna can have a low gain and provide a wide field of view, or an antenna can have a high gain and provide a narrow field of view. This field of view is a parameter of interest in both remote sensing and communication applications. Although low-gain antennas produce a wider field of view than high-gain antennas, they typically radiate less energy in the direction of interest. Summary of the invention

[0003] The present invention discloses an adjustable gain antenna. The antenna includes an RF transmitter configured to transmit an RF signal along a transmitter axis. A first refractive lens has an optical axis colinear with the transmitter axis and a second refractive lens has an optical axis colinear with the transmitter axis, wherein the first refractive lens is located between the RF transmitter and the second refractive lens. A drive mechanism is mechanically linked to the first refractive lens and the second refractive lens, wherein the drive mechanism is configured to longitudinally move the first refractive lens and the second refractive lens along the transmitter axis to change the gain of the RF transmitter.

[0004] In one or more embodiments of the antenna, the first refractive lens and the second refractive lens are composed of at least one of PLA (polylactic acid) or ABS (acrylonitrile butadiene styrene).

[0005] In one or more embodiments of the antenna, the first refractive lens and the second refractive lens are each coated with an RF transparent material.

[0006] In one or more embodiments of the antenna, the RF transparent material includes Aptek 2515AB.

[0007] In one or more embodiments of the antenna, the RF transmitter is a single-aperture RF transmitter.

[0008] In one or more embodiments of the antenna, the RF transmitter is configured to produce circular polarization.

[0009] In one or more embodiments of the antenna, the RF transmitter is configured to generate linear polarization.

[0010] In one or more embodiments of the antenna, the RF transmitter is configured to generate elliptical polarization.

[0011] In one or more embodiments of the antenna, the first refractive lens and the second refractive lens are injection molded.

[0012] In one or more embodiments of the antenna, the first refractive lens and the second refractive lens are 3D printed.

[0013] In one or more embodiments of the antenna, the RF transmitter is a circular horn antenna.

[0014] In one or more embodiments of the antenna, the RF signal includes a frequency range of 26.5-40 gigahertz (GHz).

[0015] In one or more embodiments of the antenna, the antenna comprises at least one additional refractive lens positioned along the transmitter axis, wherein the drive mechanism is configured to adjust the at least one additional refractive lens.

[0016] In one or more embodiments of the antenna, the antenna includes a mounting assembly for selecting a field of view of the antenna.

[0017] A method of operating an antenna assembly is disclosed herein, the method comprising determining a gain of the antenna assembly and positioning at least one of a first refractive lens or a second refractive lens at a first longitudinal position along a transmitter axis of an RF transmitter. An RF beam is transmitted along the transmitter axis by the RF transmitter.

[0018] In one or more embodiments of the method, the method includes positioning both the first refractive lens and the second refractive lens along the emitter axis.

[0019] In one or more embodiments of the method, the method includes rotating the antenna assembly about a point to vary the field of view of the antenna assembly in azimuth and elevation.

[0020] In one or more embodiments of the method, the RF transmitter is a single-aperture RF transmitter.

[0021] In one or more embodiments of the method, the method includes positioning the first refractive lens and the second refractive lens each at a second longitudinal position along the emitter axis to produce a second gain.

[0022] An antenna assembly is disclosed herein. The antenna assembly includes an RF transmitter configured to transmit an RF signal along a transmitter axis. A first refractive lens has an optical axis colinear with the transmitter axis and a second refractive lens has an optical axis colinear with the transmitter axis, wherein the first refractive lens is located between the RF transmitter and the second refractive lens. A drive mechanism is mechanically linked to the first refractive lens and the second refractive lens, wherein the drive mechanism is configured to longitudinally move the first refractive lens and the second refractive lens along the transmitter axis to change the gain of the RF transmitter. A mounting assembly is used to select a field of view of an adjustable gain antenna. A controller is configured to determine the gain of the antenna assembly and position at least one of the first refractive lens or the second refractive lens at a first longitudinal position along the transmitter axis of the RF transmitter. The controller is also configured to direct an RF beam along the transmitter axis with the RF transmitter. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 An example antenna assembly is illustrated in a first position having a first gain.

[0024] Figure 2 The second position having a second gain is described Figure 1 antenna assembly.

[0025] Figure 3 Another example antenna assembly is described.

[0026] Figure 4 Instructions Figure 1 An example method of an antenna assembly.

[0027] Some embodiments of the present disclosure will now be described by way of example only and with reference to the accompanying drawings.On all drawings, the same reference number represents the same element or the same type of element. DETAILED DESCRIPTION

[0028] The accompanying drawings and the following description illustrate specific exemplary embodiments of the present disclosure. Those of ordinary skill in the art will be able to design various arrangements that, although not explicitly described or shown herein, embody the principles of the present disclosure and are included within the scope of the present disclosure. In addition, any examples described herein are intended to aid in understanding the principles of the present disclosure and should be interpreted as not being limited to such specifically enumerated examples and conditions. Therefore, the present disclosure is not limited to the specific embodiments or examples described below, but is defined by the claims and their equivalents.

[0029] Figure 1The adjustable gain antenna assembly 20 is described. The antenna assembly 20 includes an RF transmitter 22, a first refractive lens 24, a second refractive lens 26, and a drive mechanism 28 for positioning the first refractive lens 24 and the second refractive lens 26 relative to the RF transmitter 22. In the illustrated example, the RF transmitter 22 is a single-aperture RF transmitter so that it transmits an RF beam limited to a single frequency band but within a frequency range of multiple frequencies, such as a GPS patch antenna. In one example, the RF transmitter 22 is a circular horn antenna and is configured to transmit an RF signal having a frequency range between 26.5-40 gigahertz (GHz) along the Ka band. The RF transmitter 22 is also configured to transmit an RF beam along a transmitter axis E extending through the first refractive lens 24 and the second refractive lens 26. The RF transmitter 22 can also generate an RF beam having a circular polarization, such as one of left-handed or right-handed circular polarization, linear polarization, or elliptical polarization.

[0030] The first refractive lens 24 and the second refractive lens 26 are positioned along the transmitter axis E, wherein the first refractive lens 24 is located in the middle or between the RF transmitter 22 and the second refractive lens 26. In one example, the first refractive lens 24 and the second refractive lens 26 are composed of at least one of a polylactic acid (PLA) material or an acrylonitrile butadiene styrene (ABS) material. The first refractive lens 24 and the second refractive lens 26 are each coated with an RF transparent material, such as Aptek 2515AB, which can protect the antenna material from environmental conditions while still allowing the transmission of the RF beam. The first refractive lens 24 and the second refractive lens 26 can be made in an injection molding process or by a three-dimensional (3D) printing process.

[0031] In one example, the first refractive lens 24 includes a first surface facing the RF transmitter 22 for receiving RF signals and a second surface opposite to the first surface. Similarly, the second refractive lens 26 includes a first surface facing the first refractive lens 24 and the RF transmitter 22 and a second surface opposite to the first surface.

[0032] The drive mechanism 28 mechanically links the first refractive lens 24 and the second refractive lens 26 to move relative to the RF transmitter 22 to vary the focal length, and therefore the gain, of the antenna assembly 20. In the illustrated example, the drive mechanism 28 utilizes a first set of linear actuators 34A movable by at least one drive motor to position the first refractive lens 24, and utilizes a second set of linear actuators 34B to longitudinally position the second refractive lens 26 along the transmitter axis E to vary the gain of the RF transmitter 22. In one example, the linear actuators are retractable, and in another example, the linear actuators include a rotatably driven threaded shaft.

[0033] The controller 40 communicates with the drive mechanism 28 to control the operation of the drive mechanism 28. Any of the various control elements (e.g., electrical or electronic components) shown in the drawings or described herein may be implemented as hardware, a processor implementing software, a processor implementing firmware, or some combination of these. For example, an element may be implemented as dedicated hardware. A dedicated hardware element may be referred to as a "processor," "controller," or some similar terms. When provided by a processor, the function may be provided by a single dedicated processor, a single shared processor, or multiple separate processors, some of which may be shared. In addition, the explicit use of the term "processor" or "controller" should not be interpreted as referring only to hardware capable of executing software, and may implicitly include, but is not limited to, digital signal processor (DSP) hardware, network processor, application specific integrated circuit (ASIC) or other circuit system, field programmable gate array (FPGA), read-only memory (ROM) for storing software, random access memory (RAM), non-temporary computer readable medium, non-volatile storage device, logic or some other physical hardware component or module.

[0034] The antenna assembly 20 is attached to the mounting assembly 38 to rotate the antenna assembly 20 around the point P so that the azimuth and elevation of the RF beam passing through the first refractive lens 24 and the second refractive lens 26 are changed. The movement of the antenna assembly 20 around the mounting assembly 38 can be managed by a controller 40 that is in electrical communication with the mounting assembly 38. This allows the antenna assembly 20 to be aimed in a given direction, or to be moved to one of a plurality of different rotational positions depending on the application. This can be helpful when the antenna assembly 20 is used in an adaptive radar configuration. In particular, the antenna assembly 20 can be operated at low gain to perform a wide target search, and can then be adjusted to a high gain to track an object more accurately. The adjustability of the gain of the antenna assembly 20 is characterized by the ability to perform multiple functions with a single antenna assembly 20.

[0035] The antenna assembly 20 may also be used for synthetic aperture radar (SAR) images to detect physical properties of objects. The antenna assembly 20 may be used at low gain to obtain an image over a wide area and then may be adjusted to high gain to create a zoomed image focused on a smaller area.

[0036] In addition, the antenna assembly 20 can be used for cross-link communication. For cross-link communication, the antenna assembly 20 can be in a low gain configuration for radar attitude detection and then transition to a high gain for high-speed communication.

[0037] Figure 3Another example antenna assembly 120 is described. Antenna assembly 120 is similar to antenna assembly 20, and except as noted below or shown in the figures, similar items between antenna assembly 20 and antenna assembly 120 will include the same numbers plus a leading "1". Assembly 120 includes an RF transmitter 122, a first refractive lens 124, a second refractive lens 126, a third refractive lens 130, and a drive mechanism 128. Drive mechanism 128 positions first refractive lens 124, second refractive lens 126, and third refractive lens 130 relative to RF transmitter 122 along a transmitter axis E to vary the gain of antenna assembly 120 with a first set of linear actuators 134A, a second set of linear actuators 134B, and a third set of linear actuators 134C, respectively. Adding third refractive lens 130 in assembly 120 allows for greater variation in gain, such as when there are size packaging constraints for antenna assembly 120.

[0038] Figure 4 An example method 100 of operating either antenna assembly 20 or 120 is described. Method 100 includes determining a gain of antenna assembly 20, 120 (block 102). The gain of antenna assembly 20, 120 will depend on the application, such as those described above, and whether the application is more suited to high, low, or another variation of the gain of the antenna assembly.

[0039] Once the gain is determined, the method 100 longitudinally positions the lenses 24, 26, 124, 126, 130 along the transmitter axis E of the transmitter 22, 122 (block 104). The position of each of the lenses 24, 26, 124, 126, 130 will determine the gain produced by the antenna assembly 20, 120. The longitudinal position of all of the lenses 24, 26, 124, 126, 130 may be predetermined by the controller 40, 140, or selected based on a given application.

[0040] With the refractive lens 24, 26, 124, 126, 130 positioned longitudinally along the transmitter axis E, the transmitter 22, 122 can then transmit an RF beam through the lens 24, 26, 124, 126, 130 (block 106). The position of the antenna assembly 20, 120 can also be varied about point P using the mounting assembly 38, 138 to control the field of view of the RF beam for a given application.

[0041] The following clauses provide example configurations of antenna assemblies and for operation Figure 1-4 Method of antenna assembly.

[0042] Item 1: An adjustable gain antenna comprising: an RF transmitter configured to transmit an RF signal along a transmitter axis; a first refractive lens having an optical axis co-linear with the transmitter axis; a second refractive lens having an optical axis co-linear with the transmitter axis, wherein the first refractive lens is located between the RF transmitter and the second refractive lens; and a drive mechanism mechanically linked to the first refractive lens and the second refractive lens, wherein the drive mechanism is configured to move the first refractive lens and the second refractive lens longitudinally along the transmitter axis to vary the gain of the RF transmitter.

[0043] Clause 2: The antenna of claim 1, wherein the first refractive lens and the second refractive lens are composed of at least one of PLA (polylactic acid) or ABS (acrylonitrile butadiene styrene).

[0044] Clause 3: The antenna of any of clauses 1-2, wherein the first refractive lens and the second refractive lens are each coated with an RF transparent material.

[0045] Clause 4: The antenna of any of clauses 1-3, wherein the RF transparent material comprises Aptek 2515AB.

[0046] Clause 5: The antenna of any of clauses 1-4, wherein the RF transmitter is a single-aperture RF transmitter.

[0047] Clause 6: The antenna of any of clauses 1-5, wherein the RF transmitter is configured to produce circular polarization.

[0048] Clause 7: The antenna of any of clauses 1-6, wherein the RF transmitter is configured to produce linear polarization.

[0049] Clause 8: The antenna of any of clauses 1-7, wherein the RF transmitter is configured to produce elliptical polarization.

[0050] Clause 9: The antenna of any of clauses 1-8, wherein the first refractive lens and the second refractive lens are injection molded.

[0051] Clause 10: The antenna of any of clauses 1-9, wherein the first refractive lens and the second refractive lens are 3D printed.

[0052] Clause 11: The antenna of any of clauses 1-10, wherein the RF transmitter is a circular horn antenna.

[0053] Clause 12: The antenna of any of clauses 1-11, wherein the RF signal comprises a frequency range of 26.5-40 gigahertz (GHz).

[0054] Clause 13: The antenna of any of clauses 1-12, comprising at least one additional refractive lens positioned along the transmitter axis, wherein the drive mechanism is configured to adjust the at least one additional refractive lens.

[0055] Clause 14: The antenna of any of clauses 1-13, comprising a mounting assembly for selecting a field of view of the antenna.

[0056] Clause 15: A method of operating an antenna assembly, the method comprising: determining a gain of the antenna assembly; positioning at least one of a first refractive lens or a second refractive lens at a first longitudinal position along a transmitter axis of an RF transmitter; and transmitting an RF beam along the transmitter axis with the RF transmitter.

[0057] Clause 16: The method of clause 15, comprising positioning both the first refractive lens and the second refractive lens along the emitter axis.

[0058] Clause 17: The method of any of clauses 15-16, comprising rotating the antenna assembly about a point to vary the field of view of the antenna assembly in azimuth and elevation.

[0059] Clause 18: The method of any of clauses 15-17, wherein the RF transmitter is a single-aperture RF transmitter.

[0060] Clause 19: The method of any of clauses 15-18, comprising positioning the first refractive lens and the second refractive lens each at a second longitudinal position along the emitter axis to produce a second gain.

[0061] Item 20: An antenna assembly comprising: an RF transmitter configured to transmit an RF signal along a transmitter axis; a first refractive lens having an optical axis co-linear with the transmitter axis; a second refractive lens having an optical axis co-linear with the transmitter axis, wherein the first refractive lens is located between the RF transmitter and the second refractive lens; and a drive mechanism mechanically linked to the first refractive lens and the second refractive lens, wherein the drive mechanism is configured to move the first refractive lens and the second refractive lens longitudinally along the transmitter axis to vary the gain of the RF transmitter; a mounting assembly for selecting a field of view of an adjustable gain antenna; and a controller configured to: determine the gain of the antenna assembly; position at least one of the first refractive lens or the second refractive lens respectively at a first longitudinal position along the transmitter axis of the RF transmitter; and direct an RF beam along the transmitter axis with the RF transmitter.

[0062] Although various embodiments have been described, the description is intended to be illustrative rather than restrictive. It will be apparent to those of ordinary skill in the art that there may be more embodiments and implementations within the scope of the embodiments. Unless specifically limited, any feature of any embodiment may be used in combination with any other feature or element in any other embodiment or replace any other feature or element in any other embodiment. Therefore, the embodiments are not limited except in accordance with the appended claims and their equivalents. In addition, various modifications and changes may be made within the scope of the appended claims.

Claims

1. An adjustable gain antenna, comprising: an RF transmitter (22, 122) configured to transmit an RF signal along a transmitter axis (E); a first refractive lens (24, 124) having an optical axis co-linear with the emitter axis (E); a second refractive lens (26, 126) having an optical axis co-linear with the transmitter axis (E), wherein the first refractive lens (24, 124) is located between the RF transmitter (22, 122) and the second refractive lens (26, 126); and A drive mechanism (28, 128) mechanically linked to the first refractive lens (24, 124) and the second refractive lens (26, 126), wherein the drive mechanism (28, 128) is configured to longitudinally move the first refractive lens (24, 124) and the second refractive lens (26, 126) along the transmitter (22, 122) axis to vary the gain of the RF transmitter (22, 122).

2. The antenna according to claim 1, wherein the first refractive lens (24, 124) and the second refractive lens (26, 126) are composed of at least one of PLA (polylactic acid) or ABS (acrylonitrile butadiene styrene).

3. The antenna of claim 1, wherein the first refractive lens (24, 124) and the second refractive lens (26, 126) are each coated with an RF transparent material. The antenna of claim 3 , wherein the RF transparent material comprises Aptek 2515AB.

5. The antenna of claim 1, wherein the RF transmitter (22, 122) is a single-aperture RF transmitter (22, 122).

6. The antenna of claim 5, wherein the RF transmitter (22, 122) is configured to produce circular polarization.

7. The antenna of claim 5, wherein the RF transmitter (22, 122) is configured to produce linear polarization.

8. The antenna of claim 5, wherein the RF transmitter (22, 122) is configured to produce elliptical polarization.

9. The antenna of claim 1, wherein the first refractive lens (24, 124) and the second refractive lens (26, 126) are injection molded.

10. The antenna of claim 1, wherein the first refractive lens (24, 124) and the second refractive lens (26, 126) are 3D printed.

11. The antenna of claim 1, wherein the RF transmitter (22, 122) is a circular horn antenna.

12. The antenna of claim 1, wherein the RF signal comprises a frequency range of 26.5-40 gigahertz (GHz).

13. The antenna of claim 1, comprising at least one additional refractive lens (130) positioned along the transmitter (22, 122) axis, wherein the drive mechanism (28, 128) is configured to adjust the at least one additional refractive lens (130).

14. The antenna of claim 1, comprising a mounting assembly (38, 138) for selecting a field of view of the antenna.

15. A method (100) of operating an antenna assembly (20, 120), the method (100) comprising: determining a gain of the antenna assembly (20, 120); positioning at least one of the first refractive lens (24, 124) or the second refractive lens (26, 126) at a first longitudinal position along a transmitter (22, 122) axis of the RF transmitter (22, 122); and An RF beam is transmitted with the RF transmitter (22, 122) along an axis of the transmitter (22, 122).

16. The method (100) of claim 15, comprising positioning both the first refractive lens (24, 124) and the second refractive lens (26, 126) along the emitter axis (E).

17. The method (100) of claim 16, comprising rotating the antenna assembly (20, 120) about a point to vary the field of view of the antenna assembly (20, 120) in the azimuth and elevation.

18. The method (100) of claim 15, wherein the RF transmitter (22, 122) is a single-aperture RF transmitter (22, 122).

19. The method (100) of claim 16, comprising positioning the first refractive lens (24, 124) and the second refractive lens (26, 126) at each second longitudinal position along the emitter (22, 122) axis to produce a second gain.

20. An antenna assembly (20, 120), comprising: an RF transmitter (22, 122) configured to transmit an RF signal along an axis of the transmitter (22, 122); a first refractive lens (24, 124) having an optical axis co-linear with the emitter axis (E); a second refractive lens (26, 126) having an optical axis co-linear with the transmitter (22, 122) axis, wherein the first refractive lens (24, 124) is located between the RF transmitter (22, 122) and the second refractive lens (26, 126); and a drive mechanism (28, 32, 128) mechanically linked to the first refractive lens (24, 124) and the second refractive lens (26, 126), wherein the drive mechanism (28, 128) is configured to longitudinally move the first refractive lens (24, 124) and the second refractive lens (26, 126) along the transmitter (22, 122) axis to vary the gain of the RF transmitter (22, 122); A mounting assembly (38, 120, 138) for selecting a field of view of an adjustable gain antenna; and A controller (40, 140) configured to: determining a gain of the antenna assembly (20, 120); positioning at least one of the first refractive lens (24, 124) or the second refractive lens (26, 126) at a first longitudinal position along a transmitter axis (E) of the RF transmitter (22, 122); and An RF beam is directed with the RF transmitter (22, 122) along the transmitter axis (E).

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