1. Field of the Invention
This invention relates to microwave reflector antennas. More particularly, the invention relates to a feed arrangement configurable for multiple feed configurations without tuning.
2. Description of Related Art
Microwave reflector antennas use a feed arrangement to launch and/or receive RF signal(s) from an RF source/receiver. The feed arrangement typically comprises a feed horn/illuminator plate launching the signal(s) with a desired feed pattern, for example with minimal back lobes, and an ortho mode transducer (OMT) for separating one or more polarities of the signal(s) into separate waveguides coupled to a desired receiver and/or transmitter.
Prior feed arrangements, for example as shown in
Competition in the reflector antenna market has focused attention on improving long-term electrical performance and minimization of overall manufacturing costs. Therefore, it is an object of the invention to provide a feed arrangement 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, where like reference numbers in the drawing figures refer to the same feature or element and may not be described in detail for every drawing figure in which they appear and, together with a general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the principles of the invention.
By providing a unitary monolithic body configured to receive simplified attachments, a microwave antenna feed arrangement configurable for multiple microwave antenna applications may be manufactured with significant manufacturing efficiencies.
As shown for example in
One skilled in the art will appreciate that the launch end 5 and back end 7 are descriptors used herein to clarify longitudinal locations and contacting interrelationships between the various elements of the feed arrangement 21. In addition to the identified positions in relation to adjacent elements along the feed arrangement 21 longitudinal axis, each individual element has a launch end 5 side and a back end 7 side, i.e. the sides of the respective element that are facing the respective launch end 5 and the back end 7 of the feed arrangement 21.
As best shown in
The feed bore 3 and the OMT bore 15 are each provided with a plurality of inward projecting shoulder(s) 19 (
As shown in
A matching ring 35, for example formed from a dielectric material, may be seated within the feed bore 3, inserted from the launch end 5. Optimizing of the feed arrangement 21 may be significantly simplified by exchanging between multiple matching ring(s) 35 provided with a dielectric material, thickness, diameter and/or inward projecting shoulder(s) 19 configured to match with a desired operating frequency and/or any corresponding impedance discontinuities, for example generated by the presence of the window 23.
Where the feed arrangement 21 will be operated with respect to a single polarity, such as in a receive only configuration, the feed bore 3 may be closed at the back end by coupling an end cap 37 to the back end 7 of the body 1, closing the feed bore 3, for example as shown in
For dual polarity operation, a signal connection may be made to the back end 7 of the body 1 coaxial with the feed bore 3. To minimize blockage of the antenna reflector (not shown), the feed waveguides (not shown) coupled to the feed arrangement 21 may be arranged in-line with one another along the longitudinal axis of the body 1. For example, as shown in
One skilled in the art will appreciate that the feed arrangement 21 may be entirely pre-tuned by the manufacturing tolerances applied to the formation of the feed and OMT bores 3,15. In modeled and measured performance, the feed arrangement 21 has been demonstrated with frequency bandwidth of 18.4% and greater than 30 dB return loss and 45 dB open and short circuit isolations.
Further, because the body 1 is unitary monolithic element, the feed arrangement 21 may be environmentally sealed by application of the window 23 and any gasket(s) 45 such as o-rings located at the interconnection(s) between the body 1 and the end cap 37 or feed elbow 39 and rotation rotator 43, if any. Thereby, the desired feed arrangement 21 may be securely RF and environmentally sealed without requiring any soldering manufacturing steps, whatsoever.
The body 1, end cap 37, feed elbow 39 and feed rotator 43 may each be configured without internal overhanging edges with respect to the feed bore 3 and/or OMT bore 15 enabling greatly simplified manufacture of these components via, for example, two-axis CNC machining and/or metal injection molding. For metal injection molding, a slight taper may be added to the various mold separation surfaces to simplify mold separation. Because the same body 1 may be used with single and dual polarity feed arrangement(s) 21 design, manufacturing set-up and product inventory requirements may be reduced. Further, because the assembly steps require only the mounting of self aligning elements upon one another and, for example, the threading of a handful of fastener(s) 47 to secure same in place, assembly may be performed by cost effective labor with reduced skill levels and/or training requirements.
Where in the foregoing description reference has been made to materials, ratios, integers or components 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.
Number | Date | Country | Kind |
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200910141928.0 | Apr 2009 | CN | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US2010/027166 | 3/12/2010 | WO | 00 | 9/16/2011 |