1. Statement of the Technical Field
The inventive arrangements relate to compact antenna system structures, and more particularly, to a compact deployable antenna reflector structure.
2. Description of the Related Art
Various conventional antenna structures exist that include a reflector for directing energy into a desired pattern. One such conventional antenna structure is a radial rib reflector design comprising a plurality of reflector ribs joined together at a common cylindrical shaped hub. The reflector ribs provide structural support to a flexible antenna reflector surface attached thereto. A plurality of wires or guidelines couple the flexible antenna reflector surface to the reflector ribs. The wires or guidelines define and maintain the shape of the flexible antenna reflector surface. The radial rib reflector is collapsible so that it can be transitioned from a deployed position to a stowed position. In the deployed position, the radial rib reflector has a generally parabolic shape. In the stowed position, the reflector ribs are folded up against each other. As a result, the antenna reflector has a stowed height approximately equal to the reflector's radius.
Another conventional antenna structure is a folding rib reflector having a similar design to the radial rib reflector design described above. However, the reflector ribs include a first rib shaft and second rib shaft joined together by a common joint. In the stowed position, the first rib shafts are folded up against the second rib shafts. As such, the antenna reflector has a stowed height that is less than the stowed height of the radial rib reflector design. However, the stowed diameter of the folding rib reflector is larger than the stowed diameter of the radial rib reflector design.
Embodiments of the present invention concern antenna reflectors and methods of deploying the antenna reflectors. Each of the antenna reflectors includes extendable ribs coupled to a centrally located hub. Each of the extendable ribs includes an inner rib rotatably coupled to the hub. Each of the extendable ribs also includes an outer rib slidingly coupled to a respective inner rib. The outer rib can be, but is not limited to, a hollow tube or a collar.
During deployment of an antenna reflector, the extendable ribs are rotated from a stowed position in which the extendable ribs are generally aligned with a central axis of the hub, to a rotated position in which the extendable ribs extend in radial directions relative to the central axis. Each of the outer ribs is linearly displaced on the inner rib from a proximal position adjacent to the hub to an extended position distal from the hub. A flexible antenna reflector surface is supported on a guideline truss structure that is under tension when each of the outer ribs is in its extended position. The guideline truss structure includes cords attached at intermediate locations along a length of each outer rib between opposing ends thereof. Each of the outer ribs is secured in its extended position with a locking mechanism or a mechanism configured to eliminate a reverse motion of said extended outer rib. During use of the antenna reflector, a shaped reflective surface is illuminated using an antenna feed supportably located in opposed relation with respect to the curved reflective surface.
The antenna reflector is re-stored to its stowed position by unsecuring the outer ribs, and linearly displacing each of the outer ribs on a respective inner rib from its extended position to its proximal position adjacent to the hub. Each of the outer ribs is linearly displaced on the respective inner rib by transforming a rotation induced by at least one motor of the hub to linear motion. The rotation is transformed to a linear motion using at least one mechanical component. The mechanical component can be selected from the group comprising a worm gear, a pinion gear, a spur gear, a pulley with a driving belt and a drive shaft.
According to an aspect of the present invention, one or more solar panels are concurrently extended with the rotating and linearly displacing outer ribs. The solar panels can be used to charge a battery. The battery can supply electrical power to the antenna system inclusive of the motor facilitating the deployment of the antenna reflector.
Embodiments will be described with reference to the following drawing figures, in which like numerals represent like items throughout the figures, and in which:
The invention described and claimed herein is not to be limited in scope by the preferred embodiments herein disclosed, since these embodiments are intended as illustrations of several aspects of the invention. Any equivalent embodiments are intended to be within the scope of this invention. Indeed, various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims.
The word “exemplary” is used herein to mean serving as an example, instance or illustration. Any aspect or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the word exemplary is intended to present concepts in a concrete fashion. As used in this application, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or”. That is, unless specified otherwise, or clear from context, “X employs A or B” is intended to mean any of the natural inclusive permutations. That is if, X employs A; X employs B; or X employs both A and B, then “X employs A or B” is satisfied under any of the foregoing instances.
The extendable rib reflector antenna described herein offers several advantages. For example, it (a) provides a simpler architecture than conventional folding rib reflector designs, (b) eliminates the need for a hub tower, (c) allows a feed tower to be provided on a surface side of a reflector, (d) has reduced guideline lengths, and (e) ensures that there is no overstretch of the flexible antenna reflector surface and guidelines.
An exemplary extendable rib reflector antenna 100 will now be described in relation to
Referring now to
As shown in
The antenna feed structure 102 generally comprises an antenna feed 104 configured to convey radio waves between a transceiver and the antenna reflector surface 122. Antenna feed structures 102, 104 are well known to those having ordinary skill in the art, and therefore will not be described in detail herein. However, it should be understood that the antenna feed method can include any suitable antenna feed structure. For example, the antenna feed structure 102, 104 may include an antenna horn, an orthomode transducer, a frequency diplexer, a waveguide, waveguide switches, a rotary joint, active patch elements and electronically steerable feed.
The antenna feed structure 102 is provided on a reflective surface side 152 of the extendable rib reflector antenna 100 as shown in
The reflector structure 150 generally has a circular, parabolic shape when the extendable rib reflector antenna 100 is in its fully extended position as shown in
The antenna reflector surface 122 is formed from any material that is suitable to serve as an antenna's reflective surface. Such materials include, but are not limited to, reflective wire woven mesh materials similar to light weight woven fabrics. In its fully extended position shown in
The antenna reflector surface 122 extends at least partially around the central longitudinal axis 170 of the extendable rib reflector antenna 100. As such, the antenna reflector surface 122 is defined by a curve symmetrically rotated about the central longitudinal axis 170 of the extendable rib reflector antenna 100. Although the curve of the antenna reflector surface 122 shown in
The extendable ribs 106a, 106b, 106c, 106d, 106e, 106f, 106g are rotatably coupled to the hub 120. As such, the extendable ribs 106a, 106b, 106c, 106d, 106e, 106f, 106g can be rotated from the stowed position shown in
Each extendable rib 106a, 106b, 106c, 106d, 106e, 106f, 106g includes an inner rib 108 and a outer rib 110 movably disposed on the inner rib 108. In this regard, it should be understood that the inner rib 108 has at least a proximal end 112 attached to the hub 120. The outer rib 110 is disposed on the inner rib 108 so as to allow the outer rib 110 to be linearly displaced on the inner rib 108. The linear displacement of the outer rib 110 is achieved by transforming a rotation induced by at least one motor of the hub 120 to linear motion. The rotation can be transformed to a linear motion using at least one mechanical system. The mechanical system can include, but is not limited to, a worm gear, a pinion gear, a spur gear, a pulley and a drive shaft. At least a portion of the mechanical system can be disposed in the inner and/or outer ribs 108, 110. Still, those skilled in the art will appreciated that linear displacement of the outer rib can be accomplished by any other suitable means.
The linear displacement of the outer rib 110 allows the extendable rib 106a, 106b, 106c, 106d, 106e, 106f, 106g to be expanded from a stowed configuration shown in
Each of the extendable ribs 106a, 106b, 106c, 106d, 106e, 106f, 106g includes a locking mechanism (not shown in
As will be apparent to those having ordinary skill in the art, the extensibility of the ribs 106a, 106b, 106c, 106d, 106e, 106f, 106g allows the stowed height of the extendable rib reflector antenna 100 to be reduced as compared to conventional radial rib reflector designs. The extensibility of the ribs 106a, 106b, 106c, 106d, 106e, 106f, 106g also reduces the stowed diameter of the extendable rib reflector antenna 100 as compared to the conventional folding rib reflector designs. The extensibility of the ribs 106a, 106b, 106c, 106d, 106e, 106f, 106g also ensures that the antenna reflector surface 122 will not be over stretched during deployment of the extendable rib reflector antenna 100.
As shown in
The guideline truss structure 132 defines and maintains the shape of the extendable rib reflector antenna 100 when it is in use. In this regard, the guideline truss structures 132 and 160 include a plurality of interconnected cords (or thread like strings) 176. The cords 176 are positioned between the antenna reflector surface 122 and the extendable ribs 106a, 106b, 106c, 106d, 106e, 106f, 106g so as to provide structural stiffness to the antenna reflector surface 122 when the extendable rib reflector antenna 100 is in-use. When the extendable rib reflector antenna 100 is in its fully deployed configuration, the guideline truss structures 132 and 160 are stable structures under tension. The tension is achieved by applying pulling forces to the cords ends by means of compression member 142 which is mechanically attached to the outer rib 110 so as to take up slack in the cords. The pulling forces are applied to the cords 176 at least partially by the extendable ribs 106a, 106b, 106c, 106d, 106e, 106f, 106g. An exemplary configuration of the cords 176 will be described below in relation to
As shown in
The solar energy collectors 180 are photovoltaic type solar panels which are well known to those having ordinary skill in the art, and therefore will not be described in detail herein. However, it should be understood that the solar panel 180 can include, but is not limited to, a thin film rolled solar panel and/or a fan fold solar panel, adopting folding methods known to persons having ordinary skill in the art. The solar panel 180 is tensioned into a stable configuration in its deployed state as shown in
The solar panel 180 is coupled to the outer ribs 110 of the extendable ribs 106a, 106b, 106c, 106d, 106e, 106f, 106g via any suitable mechanical connectors 182. Such mechanical connectors include, but are not limited to, screws, rivets, clips, springs and a variety of adhesives (e.g., glue). Springs can advantageously be used at the interfaces of the solar panel and outer ribs 110 to ensure that appropriate tension loads are placed on the solar panel 180 without placing undue loads in the supporting extendable ribs 106a, 106b, 106c, 106d, 106e, 106f, 106g.
Although the solar panel 180 is shown in
Referring now to
As shown in
The inner rib 408, 508, 608 is a structural member with a proximal end 412, 512, 612 and a distal end 414, 514, 614. The outer rib 410, 510, 610 is preferably arranged to move linearly along the length of the inner rib 408, 508, 608. To permit such motion, the outer rib 410, 510, 610 can be a hollow tube 410 as shown in
According to another embodiment of the invention, the extendable ribs 106a, 106b, 106c, 106d, 106e, 106f, 106g can include cuffs instead of the collars 510, 610 shown in
A cross sectional view of another exemplary extendable rib reflector 700 is provided in
As shown in
Referring now to
The deployment sequence will now be described in relation to
Referring now to
Referring now to
Referring now to
Referring now to
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, to the extent that the terms “including”, “includes”, “having”, “has”, “with”, or variants thereof are used in either the detailed description and/or the claims, such terms are intended to be inclusive in a manner similar to the term “comprising.”
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
All of the apparatus, methods and algorithms disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the invention has been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the apparatus, methods and sequence of steps of the method without departing from the concept, spirit and scope of the invention. More specifically, it will be apparent that certain components may be added to, combined with, or substituted for the components described herein while the same or similar results would be achieved. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the invention as defined.
Number | Name | Date | Kind |
---|---|---|---|
2709220 | Spector | May 1955 | A |
3574447 | Ruble | Apr 1971 | A |
4845511 | Grayson et al. | Jul 1989 | A |
5146719 | Saito et al. | Sep 1992 | A |
5864324 | Acker et al. | Jan 1999 | A |
6844862 | Cencich et al. | Jan 2005 | B1 |
7782530 | Krumel et al. | Aug 2010 | B1 |
20070200789 | Bassily | Aug 2007 | A1 |
Number | Date | Country |
---|---|---|
0984511 | Mar 2000 | EP |
4 288705 | Oct 1992 | JP |
Entry |
---|
Takano T et al: “Large Deployable Antenna With Cable Constitution for Satellite-Use”, Denshi Joho Tsushin Gakkai Ronbunshi. B-2 Transactions of the Institute of Electronics, Information and Communication Engineers. Section J-B-2, Tokyo, JP, vol. J81-B-II, No. 7, Jul. 1, 1998, pp. 673-682, XP009009803, ISSN: 0915-1885. |
D'Addario, L R: “Microwave technology innovations in orbiting VLBI”, Microwave Symposium Digest, 1992., IEEE MTT-S International Albuquerque, NM, USA Jun. 1-5, 1992, New York, NY, USA,IEEE, US, Jun. 1, 1992, pp. 1375-1378, XP010063032, DOI: D01:10.1109/MWSYM.1992.188262 ISBN: 978-0-7803-0611-0. |
Harris Corporation, European Search Report mailed Apr. 12, 2011, European Application No. 11000783.8. |
Number | Date | Country | |
---|---|---|---|
20110187627 A1 | Aug 2011 | US |