Antenna arrangement for aerospace

Abstract

According to an example aspect of the present invention, there is provided an antenna arrangement for aerospace, the antenna arrangement comprising a first line antenna element extending from the center of the antenna arrangement to a first location at an edge of the antenna arrangement, a second line antenna element extending from the center of the antenna arrangement to a second location at the edge of the antenna arrangement, wherein the second line antenna element is adjacent to the first line antenna element and at least one leaky wave antenna element between the first line antenna element and the second line antenna element, wherein the at least one leaky wave antenna element is arranged to use electromagnetic energy leaking from at least one of: the first line antenna element or the second line antenna element, to radiate and direct power.

Description

ANTENNA ARRANGEMENT FOR AEROSPACEFIELD

[0001] The field of the present disclosure relates in general to an antenna arrangement and more specifically, to an antenna arrangement for aerospace.BACKGROUND

[0002] The term aerospace is generally related to atmosphere and outer space. Aerospace applications may comprise, for example, drones and artificial satellites, such as solar sails but are not limited to such. In case of aerospace applications, one important issue is weight because aerospace systems should be as light as possible. Thus, also antenna arrangements for aerospace should be as light as possible and large antenna area is required for high gain antennas. In addition, it would be desirable to enable large antennas for small satellites.SUMMARY OF THE INVENTION

[0003] The invention is defined by the features of the independent claims. Some specific embodiments are defined in the dependent claims.

[0004] According to an aspect of the present disclosure, there is provided an antenna arrangement for aerospace, the antenna arrangement comprising a first line antenna element extending from the center of the antenna arrangement to a first location at an edge of the antenna arrangement, a second line antenna element extending from the center of the antenna arrangement to a second location at the edge of the antenna arrangement, wherein the second line antenna element is adjacent to the first line antenna element. The antenna arrangement further comprises at least one leaky wave antenna element between the first line antenna element and the second line antenna element, wherein the at least one leaky wave antenna element is arranged to use electromagnetic energy leaking from at least one of: the first line antenna element or the second line antenna element, to radiate and direct power.BRIEF DESCRIPTION OF THE DRAWINGS

[0005] FIGURE 1 illustrates a first example of an antenna arrangement in accordance with at least some embodiments of the present disclosure;

[0006] FIGURE 2 illustrates a first design option in accordance with at least some embodiments of the present disclosure;

[0007] FIGURE 3 illustrates S-parameters in accordance with the first design option in accordance with at least some embodiments of the present disclosure;

[0008] FIGURE 4 illustrates a second design option in accordance with at least some embodiments of the present disclosure;

[0009] FIGURE 5 illustrates S-parameters in accordance with the second design option in accordance with at least some embodiments of the present disclosure;

[0010] FIGURE 6 illustrates a second example of an antenna arrangement in accordance with at least some embodiments of the present disclosure.

[0011] FIGURE 7 illustrates a first example of a monopole / dipole feed in accordance with at least some embodiments of the present disclosure;

[0012] FIGURE 8 illustrates a radiation pattern associated with the first example of the monopole / dipole feed in accordance with at least some embodiments of the present disclosure;

[0013] FIGURE 9 illustrates a second example of a monopole / dipole feed in accordance with at least some embodiments of the present disclosure;

[0014] FIGURE 10 illustrates a radiation pattern associated with the second example of the monopole / dipole feed in accordance with at least some embodiments of the present disclosure;

[0015] FIGURE 11 illustrates a third example of a monopole / dipole feed in accordance with at least some embodiments of the present disclosure;

[0016] FIGURE 12 illustrates a radiation pattern associated with the third example of the monopole / dipole feed in accordance with at least some embodiments of the present disclosure;

[0017] FIGURE 13 illustrates a fourth example of a monopole / dipole feed in accordance with at least some embodiments of the present disclosure;

[0018] FIGURE 14 illustrates a radiation pattern associated with the fourth example of the monopole / dipole feed in accordance with at least some embodiments of the present disclosure.EMBODIMENTS

[0019] Embodiments of the present disclosure are related to an antenna arrangement for aerospace. Aerospace applications, such as deep space satellites, may benefit significantly from solar sail propulsion systems. However, long range communications also need larger antennas which add weight penalty to the mission design. This weight penalty is against the idea of having a solar sail, since minimum mass is needed to maximize the use of solar sail. Integrating antennas to solar sail can significantly change this story by offering lower mass antenna along with high gain due to large aperture area. Similar issues arise in other aerospace applications as well, such as in case of drones. Embodiments of the present disclosure therefore provide a lightweight antenna arrangement for aerospace.

[0020] FIGURE 1 illustrates a first example of an antenna arrangement in accordance with at least some embodiments. The antenna arrangement 10 illustrated in FIGURE 1 may comprise a thin membrane antenna. In FIGURE 1 there is provided an antenna arrangement 10 comprising line antenna elements 20-26, such as dipole and / or monopole antennas in plane and / or an array of dipole and / or monopole antennas placed out of plane on elements 20-26, and array / leaky wave antenna elements 30 - 36. Leaky wave antenna elements 30 - 36 may be defined as travelling wave antennas, wherein the main radiating method is to exploit a travelling wave on a guiding structure and a phase velocity is larger than the speed of light. Alternatively, or in addition, leaky wave antenna elements 30 - 36 may form a hybrid antenna system where surface waves guided along a modulated structure gradually leak energy into free space, forming a radiated beam. The modulation of the surface, based on holographic principles, encodes specific interference patterns, enabling precise controlover the phase and amplitude of the emitted waves to shape the radiation pattern dynamically.

[0021] The antenna arrangement 10 is for aerospace, e.g., for an artificial satellite or a drone. The antenna arrangement 10 comprises a first line antenna element 20 extending from the center 40 of the antenna arrangement 10 to a first location 50 at an edge of the antenna arrangement 10. The antenna arrangement 10 further comprises a second line antenna element 22 extending from the center 40 of the antenna arrangement 10 to a second location 52 at the edge of the antenna arrangement 10, wherein the second line antenna element 22 is adjacent to the first line antenna element 20. The antenna arrangement 10 also comprises at least one leaky wave antenna element 30 between the first line antenna element 20 and the second line antenna element 22, wherein the at least one leaky wave antenna element 30 is arranged to use electromagnetic energy leaking from at least one of the first line antenna element 20 or the second line antenna element 22, to radiate and direct power.

[0022] The antenna arrangement 10 is fed via the center 40 of the antenna arrangement 10. The antenna arrangement 10 may be an artificial satellite, such as a CubeSat satellite but not limited to. In some embodiments, the antenna arrangement 10 is, or is for, a solar sail but is not limited to such. Alternatively, or in addition, the antenna arrangement 10 may be, or be for, a drag sail, thermal blanket, Whipple shield, etc.

[0023] The antenna arrangement 10 may be a thin membrane antenna. A thin membrane antenna may be a lightweight, flexible, and ultra-thin antenna structure designed for applications where mass and volume constraints are critical, such as in space exploration, aerospace, and portable communication systems. Thin membrane antennas utilize advanced materials, such as polymer films or composite substrates, to achieve high structural flexibility while maintaining the ability to transmit and receive electromagnetic signals effectively. Thin membrane antennas are often deployable or foldable, making them ideal for compact storage and subsequent expansion in their operational environment. Furthermore, thin membrane antennas may be employed in diverse systems, including satellite communications, synthetic aperture radars, and multifunctional surfaces integrated with solar cells or other components.

[0024] Embodiments of the present disclosure comprise one or more of the following features:• Monopole / dipole antennas may be used as a large feed system for solar sail and / or thin membrane antenna. That is, the at least one of the first 20 or second 22 line antenna elements may be a monopole antenna or an arm of dipole antenna or may have multiple smaller monopole in an array formation, such as an arm of a sleeve dipole antenna;• The linearly polarized wave form may be used to excite linear, circular or elliptical wave form on a thin membrane antenna array. That is, at least one of the first line antenna element 20 or the second line antenna element 22 may be arranged to generate a linearly polarized wave form to excite a linear, circular or elliptical wave form on the at least one leaky wave antenna element;• A phase shift in different dipoles may also be used to have circular polarization in feed, further exciting a thin membrane antenna. That is, the phase shift between the first 20 and second 22 line antenna elements may be arranged to provide a circular polarization feed to the at least one leaky wave antenna element 30;• Multiple monopole / dipole feeds may be used to excite multiple frequencies based on printed antennas, thus enabling frequency divergence. That is, the first 20 and second 22 line antenna elements may be arranged to excite different frequencies of multiple frequencies individually;• The radiation pattern of a solar sail may be optimized to be omnidirectional or directional based on the use case requirement. That is, the antenna arrangement 10 may be arranged to radiate and direct power with a radiation pattern, said radiation pattern being omnidirectional or directional;• at least one of the first line antenna element or the second line antenna element may be within a coupling distance of the at least one of the leaky wave antenna elements.

[0025] In some embodiments, the antenna arrangement 10 may have a polygon shape, such as a rectangular shape as illustrated in FIGURE 1, or a circular shape. If the antenna arrangement 10 has the polygon shape, and the first 50 and second 52 locations are at adjacent comers of the polygon shape. The antenna arrangement 10 may be substantially two-dimensional.

[0026] In some embodiments, each of the line antenna elements 20 - 26 may comprise an array of antenna elements arranged substantially in a line. That is, each of the line antenna elements 20 - 26 may be a linear array feed.

[0027] FIGURE 2 illustrates a first design option in accordance with at least some embodiments of the present disclosure. More specifically, in FIGURE 2 an example of a sleeve dipole antenna is illustrated. FIGURE 3 illustrates S-parameters in accordance with the first design option.

[0028] FIGURE 4 illustrates a second design option in accordance with at least some embodiments of the present disclosure. More specifically, in FIGURE 4 another example of a sleeve dipole antenna is illustrated. The sleeve dipole antenna may be placed in coupling distance from copper printed thin membranes structures. FIGURE 5 illustrates S-parameters in accordance with the second design option. These two designs may be compared for their return loss parameters and operating range. Both antennas have similar performance as shown in FIGURES 3 and 5.

[0029] The obtained radiation patterns of the two designs may differ fundamentally though. The first design option may provide an omnidirectional radiation pattern while the second design option may provide a comparatively directional radiation pattern, compared to the first design. Moreover, the first design option may offer a directivity of 2.59 dB whereas the second design option may offer a directivity of 6.03 dB in front and back direction. The radiated power be more than doubled in the second design option. This is effectively what a line feed can offer for a thin membrane reflective surface antenna.

[0030] FIGURE 6 illustrates a second example of an antenna arrangement in accordance with at least some embodiments of the present disclosure. As illustrated in FIGURE 6, the antenna arrangement 10 may comprise multiple leaky wave antenna elements between adjacent line antenna elements. For example, the antenna arrangement 10 may comprise multiple leaky wave antenna elements 30 (in variable dimensions and orientation, but not limited to) between the first line antenna element 20 and the second line antenna element 22.

[0031] As illustrated in FIGURE 6, each line antenna element may extend from the center 40 of the antenna arrangement 10 to a different location at an edge of the antenna arrangement 10, wherein adjacent antenna elements may extend to adjacent locations at the edges of the antenna arrangement 10. Moreover, the antenna arrangement 10 may comprise multiple leaky wave antenna elements between adjacent line antenna elements, wherein each of said leaky wave antenna element may be arranged to use electromagnetic energy leaking from at least one of line antenna elements adjacent to it.

[0032] Embodiments of the present disclosure provide several advantages and benefits, for example:• Line feed can offer a broadband performance;• Line feed antenna can offer consistent excitation on a large area (multiple elements) of thin membrane;• The deployment of antenna may be 2D as compared to other solution that have 3D deployment. Thus, the deployment may be less complex and antenna is light weight;• Modifying the radiation pattern, such as adjusting between a narrow or wide beam, involves altering the element pattern on a thin membrane. Typically, this requires changes to both the feed location and reflector elements in reflect array antennas. In contrast, parabolic reflector antennas do not allow for such modifications;• The weight of the antenna may be much lower than other similar antennas working on similar frequency range and offering similar gain and directivity;• The stowage volume of this antenna may be much smaller than other similar.• Multiple frequency radiation beams can be generated more easily than other antenna design options which typically (Parabolic dish antenna) will require a frequency dependent feed antenna placed out of plane, making the antenna assembly more complex.

[0033] FIGURE 7 illustrates a first example of a monopole / dipole feed in accordance with at least some embodiments of the present disclosure. FIGURE 8 illustrates a radiation pattern associated with the first example of the monopole / dipole feed in accordance with at least some embodiments of the present disclosure.

[0034] FIGURE 9 illustrates a second example of a monopole / dipole feed in accordance with at least some embodiments of the present disclosure. FIGURE 10 illustrates a radiation pattern associated with the second example of the monopole / dipole feed in accordance with at least some embodiments of the present disclosure.

[0035] FIGURE 11 illustrates a third example of a monopole / dipole feed in accordance with at least some embodiments of the present disclosure. FIGURE 12 illustrates a radiation pattern associated with the third example of the monopole / dipole feed in accordance with at least some embodiments of the present disclosure.

[0036] FIGURE 13 illustrates a fourth example of a monopole / dipole feed in accordance with at least some embodiments of the present disclosure. FIGURE 14 illustrates a radiation pattern associated with the fourth example of the monopole / dipole feed in accordance with at least some embodiments of the present disclosure.

[0037] It is to be understood that the embodiments of the invention disclosed are not limited to the particular structures, process steps, or materials disclosed herein, but are extended to equivalents thereof as would be recognized by those ordinarily skilled in the relevant arts. It should also be understood that terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting.

[0038] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment.

[0039] As used herein, a plurality of items, structural elements, compositional elements, and / or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary. In addition, various embodiments and example of the present invention may be referred to herein along with alternatives for the various components thereof. It is understood that such embodiments, examples, and alternatives are not to be construed as de facto equivalents of one another, but are to be considered as separate and autonomous representations of the present invention.

[0040] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of lengths, widths, shapes, etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoidobscuring aspects of the invention.

[0041] While the forgoing examples are illustrative of the principles of the present invention in one or more particular applications, it will be apparent to those of ordinary skill in the art that numerous modifications in form, usage and details of implementation can be made without the exercise of inventive faculty, and without departing from the principles and concepts of the invention. Accordingly, it is not intended that the invention be limited, except as by the claims set forth below.

[0042] The verbs “to comprise” and “to include” are used in this document as open limitations that neither exclude nor require the existence of also un-recited features. The features recited in depending claims are mutually freely combinable unless otherwise explicitly stated. Furthermore, it is to be understood that the use of "a" or "an", i.e. a singular form, throughout this document does not exclude a plurality.INDUSTRIAL APPLICABILITY

[0043] At least some embodiments of the present disclosure find industrial applicability in aerospace applications.REFERENCE SIGNS LIST

Claims

CLAIMS:

1. An antenna arrangement for aerospace, the antenna arrangement comprising:- a first line antenna element extending from the center of the antenna arrangement to a first location at an edge of the antenna arrangement;- a second line antenna element extending from the center of the antenna arrangement to a second location at the edge of the antenna arrangement, wherein the second line antenna element is adjacent to the first line antenna element; and- at least one leaky wave antenna element between the first line antenna element and the second line antenna element, wherein the at least one leaky wave antenna element is arranged to use electromagnetic energy leaking from at least one of: the first line antenna element or the second line antenna element, to radiate and direct power.

2. The antenna arrangement according to claim 1, wherein the antenna arrangement further comprises a thin membrane comprising the at least one leaky wave antenna element.

3. The antenna arrangement according to claim 1 or claim 2, wherein at least one of the first or second line antenna elements is a monopole antenna or an arm of dipole antenna, such as an arm of a sleeve dipole antenna.

4. The antenna arrangement according to any one of the preceding claims, wherein the antenna arrangement is for an artificial satellite.

5. The antenna arrangement according to any one of the preceding claims, wherein the antenna arrangement is, or is for, a solar sail.

6. The antenna arrangement according to any one of the preceding claims, wherein at least one of the first line antenna element or the second line antenna element is within a coupling distance of the at least one of the leaky wave antenna elements.

7. The antenna arrangement according to any one of the preceding claims, wherein the phase shift between the first and second line antenna elements is arranged to provide a circular polarization feed to the at least one leaky wave antenna element.

8. The antenna arrangement according to any one of the preceding claims, wherein the first and second line antenna elements are arranged to excite different frequencies.

9. The antenna arrangement according to any one of the preceding claims, wherein the antenna arrangement has a polygon shape, such as a rectangular shape, or a circular shape.

10. The antenna arrangement according to claim 9, wherein the antenna arrangement has the polygon shape, and the first and second locations are at adjacent comers of the polygon shape.

11. The antenna arrangement according to any one of the preceding claims, wherein the antenna arrangement is arranged to radiate and direct power with a radiation pattern, said radiation pattern being omnidirectional or directional.

12. The antenna arrangement according to any one of the preceding claims, wherein at least one of: the first line antenna element or the second line antenna element is arranged to generate a linearly polarized wave form to excite a linear, circular or elliptical wave form on the at least one leaky wave antenna element.

13. The antenna arrangement according to any one of the preceding claims, wherein the antenna arrangement is substantially two-dimensional.

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