Space Systems/loral, LLC

George Hardie

Terry M Smith

Juan Duarte

Douglas Burr

A waveguide slot array antenna system, for use with a communications system 30 disposed on a satellite. The waveguide slot array antenna system comprises a feed waveguide having an input port and multiple output ports, a waveguide slot array having a plurality of slots formed therein that is coupled to the feed waveguide, and a waveguide lens disposed adjacent to the waveguide slot array. The phase of each contributing radiating waveguide is controlled to achieve radiation pattern shaping. Inner dimensions of the rectangular waveguides are designed to provide a phase velocity inside each waveguide that results in the appropriate radiated phase at the output of the waveguides. The phase radiated by each rectangular waveguide is determined by design, and the radiation pattern that results from the combined contributions of the array can be shaped to produce a complex radiation contour. This significantly increases the efficiency with which signals are directed to intended regions without coverage directed to unintended regions.

Waveguide slot array capable of radiating shaped beams

Array fed multiple beam antenna systems and methods for use on an orbiting spacecraft carrying a communication system. The antenna systems include a reflector and a relatively small array feed compared to the reflector. The array feed has feeds (radiators) that illuminate the reflector and that are disposed in a focal plane of the reflector. A power division network excites the radiators of the feeds. The antenna system is capable of very wide scan angle operation and may be used to provide multiple spot beam coverage over the surface of the Earth viewed from a synchronous orbit spacecraft. Phase aberration normally associated with scanning is corrected by adjusting excitation coefficients of each array feed. The spot beams are scanned across a field of regard by controlling the position of each feed in the focal plane and using the appropriate amplitude and phase distribution associated with a particular spot beam (array feed). The amplitude and phase distributions may be fixed or varied during operation. A dual band system includes a second array feed and a frequency selective surface disposed between the array feeds that optimizes the respective array feeds. Use of the frequency selective surface in dual band implementations produces a very efficient communication system.

Array fed multiple beam array reflector antenna systems and method

A communication system and antenna system for use on a satellite. The communication system includes a transmitter and/or a receiver that are respectively coupled to the antenna system. The antenna system includes a plurality of stepped slot waveguides that each have a plurality of slots disposed in a broadwall thereof that form an array of slots. Adjacent slots of each waveguide are offset from a centerline of the respective waveguide and are spaced at half guide wavelength intervals, and selected slots are thus located at a different axial positions relative to other slots in the array. A feed waveguide having in input/output port is provided that couples RF energy between the plurality of stepped slot waveguides and the communication system. The stepped waveguide slot array antenna system provides phase control of the beam pattern produced thereby.

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Santa Barbara, CA, United States of America

George Hardie