Earth Station Antennas utilize a reflector to concentrate satellite signals upon a sub reflector and or feed assembly. A large reflector concentrates weak signals, enabling low power high bandwidth satellite communications.
Large reflectors may be formed from a plurality of segments that are interconnected to form the desired reflector surface. Although smaller reflector segments improve the portability and repairability of the resulting antenna, each additional segment interconnection introduces the opportunity for shape errors in the assembled reflector due to cumulative misalignment and or warping of the individual segments.
Therefore, it is an object of the invention to provide an apparatus that overcomes deficiencies in the prior art.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the general and detailed descriptions of the invention appearing herein, serve to explain the principles of the invention.
The inventor has recognized that, for shape accuracy, mobility and speed of assembly, an antenna reflector may be formed from segments that with a plurality of point to point interconnections. The point to point, rather than surface to surface, segment interconnections enable cost efficient precision segment interconnection keying during reflector assembly.
In the exemplary embodiments herein, the segmented antenna reflector is demonstrated as a generally parabolic circular dish reflector surface, for use in a mobile satellite earth station antenna. Alternatively, one skilled in the art will recognize that the reflector segment(s) may be formed in a range of other shapes and configurations, for example generally rectangular or elliptical, to form a reflector surface with an alternative shape, such as a planar reflector or an inner or outer toroidal section.
A first exemplary embodiment of a segmented reflector 2 is described in greater detail with reference to
The reflector 2 is comprised of a central segment 4, best shown in
The central segment 4 is generally circular, presenting a common peripheral surface 7 to which each of the plurality of intermediate segment(s) 6 mate with along an inner surface 9. A mounting surface 5 formed on the back of the central segment 4, reinforces the central segment 4 and provides a connection surface for an antenna mount, not shown. Side surface(s) 10 of each intermediate segment 6 may be linear, for example, extending along a radius line from a center of the central segment 4. The outer surface 12 of each intermediate segment 6 may be formed as an arc segment from the center of the central segment 4, thus providing a common surface profile for each of the peripheral segment(s) 8. The peripheral segment(s) 8 repeat the geometry of the intermediate segment(s) 6 based upon a larger arc radius and may also include features at the outer surface 12 that individually or in cooperation with adjacent peripheral segment(s) 8 form peripheral edge notch(s) 14 configured for antenna backlobe suppression. Further, the edge notch(s) 14 may be applied to reduce the shipping case size requirements, without significantly affecting electrical performance of the assembled antenna.
To improve the interlocking, alignment, shape accuracy and overall strength aspects of the reflector 2, where the peripheral segment(s) 8 mate with a portion of the intermediate segment(s) 6 outer surface 12 having a joint between adjacent intermediate segment(s) 6, the peripheral segment(s) 8 may be positioned to straddle both sides of the joint rather than align the joint with further joints between peripheral segment(s).
The various segments are interconnected via a plurality of means for locking such as cams, latches, captive bolts, over center latches, clamps, spring clips, threaded or snap fasteners or the like spaced around the periphery of each segment. The means for locking is demonstrated in the exemplary embodiment configured to share a common body 16 to which a range of differently configured end face(s) 18 may be attached. Arranged in pairs, the end face 18 first face 29 applied to each body 16 is selected to be complimentary to the opposing end face 18 second face 31 that it will connect with. The end face(s) 18 are aligned in radial pairs(s) 19 when connecting between the central segment 4 and one of the intermediate segment(s) 6 or between the intermediate segment(s) 6 and the peripheral segment(s) 8. The opposing end face(s) 18 are aligned in lateral pair(s) 21 when connecting between adjacent intermediate segment(s) 6 or peripheral segment(s) 8.
The body(s) 16 function as hardpoint(s) of the segments, allowing the remainder of each segment to be formed from lightweight and or cost efficient materials. The body(s) 16 may be fastened to the different segments using a means for fastening complimentary to the selected segment material. For example, the body(s) 16 may be bolted, riveted, welded, glued, integrally molded or machined in place upon the segments. Where additional reinforcement is desired, the area proximate the body 16 of each segment may be reinforced, for example with a metal insert, plate or the like. Each end face 18 may be configured for removable fastener attachment to the respective body 16 via common hand tools such as screw drivers and or allen keys for ease of field re-configuration and or repair. One or more body alignment pin(s) 20 may be applied to precision align each end face 18 to the corresponding body 16. To compensate for any manufacturing variances with respect to the various segments and or alignment of the attached body(s) 16, the end face(s) 18 interconnection with the respective body(s) 16 may be adapted for fine tuning via shims or spacers located between the body(s) 16 and the end face(s) 18. Alternatively, the end face(s) 18 may be permanently attached to each respective body 16, for example, once the shape accuracy of the assembled reflector has been verified.
On each segment, one of the radial pairs 19 along the arc surface may include a locating pin 26 into socket 28 as shown for example in
The means for locking couples the radial and lateral pairs to one another, end face 18 to end face 18. In the first exemplary embodiment, as shown in
Where the segments are formed with arc shaped inner and outer mating surfaces to enable segment standardization, it is preferred that only one of the radial pairs is configured with the locating pin 26 into socket 28 end face 18. Where multiple locating pin 26 into socket 28 end face 18 pairs are applied, at least one of the locating pin 26 into socket 28 end face 18 radial pairs would require an angle modification, increasing the number of unique components and or complicating the positioning of the body(s) 16 with respect to the segment edge surfaces.
To accommodate the insertion of at least one (for example the final one) of the ring of intermediate and peripheral segment(s) 6, 8 into a U-shaped opening formed by the adjacent segments during reflector 2 assembly, the remainder of the end face 18 radial and or lateral pairs may be formed with tab 30 of a first face 29 into slot 32 of a second face 31 that together form an interlocking feature with a single axis of alignment, as shown for example in
As best shown in
The precision aligned end face 18 to end face 18 connection maintains the desired reflector surface geometry but greatly reduces the precision required during segment fabrication, because only the end face 18 surface(s) rather than the entire segment edge surface need to be prepared for mating with a high degree of parallelism along their extents. Thereby, manufacturing costs are significantly reduced and the possibility for deformation of the reflector surface via rigid interconnection of slightly out of parallel, less than fully planar and or damaged segment edge surfaces is avoided.
As shown in
Although the invention has been described with the assistance of an exemplary embodiment including a central segment 4 with a single ring each of intermediate and peripheral segments 6, 8 one skilled in the art will appreciate that the benefits of the invention may be realized in smaller or larger embodiments, depending upon the desired maximum reflector segment size and the desired antenna reflector surface area. For example, where smaller reflector surface area and or larger segment dimensions are desired, the ring of peripheral segments 8 may be omitted. Similarly, where a large reflector surface and or small reflector segment dimensions are desired, multiple successive rings of intermediate and or peripheral segments 6, 8 may be applied.
The present invention enables large surface area reflector surfaces comprised of easy to transport, assemble and or repair standardized segments and means for locking. The precision enabled by interconnection between the end face(s) 18, only, instead of along the full extent of the various segment edge surfaces, greatly increases the shape accuracy of the assembled reflector. Because individual segment edge surface dimensional precision requirements are reduced, advanced lightweight materials such as carbon fiber may be applied to the segment(s) without prohibitively increasing the overall costs of the resulting antenna reflector.
Where in the foregoing description reference has been made to ratios, integers, components or modules having known equivalents then such equivalents are herein incorporated as if individually set forth.
While the present invention has been illustrated by the description of the embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative apparatus, methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departure from the spirit or scope of applicant's general inventive concept. Further, it is to be appreciated that improvements and/or modifications may be made thereto without departing from the scope or spirit of the present invention as defined by the following claims.
This application claims the benefit of U.S. Provisional Patent Application No. 60/940,035, titled “Segmented Antenna Reflector”, filed May 24, 2007 by Richard Haight and hereby incorporated by reference in its entirety. Also demonstrative of related aspects of a Mobile Antenna System that incorporates elements of the invention are two U.S. Utility patent applications titled 1) “Mobile Antenna Support” and 2) “Rotatable Antenna Mount”, both applications by Richard Haight inventor of the present invention, both filed May 23, 2008 and both hereby incorporated by reference in their respective entirety.
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Number | Date | Country | |
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20080291118 A1 | Nov 2008 | US |
Number | Date | Country | |
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60940035 | May 2007 | US |