Abstract: A spacecraft includes an antenna reflector coupled with an antenna pointing mechanism (APM), a beam forming network including variable amplitude and phase (VAP) adjusting arrangements, a tracking feed that receives a beacon signal by way of the reflector, and an autotrack receiver that measures pointing errors of the reflector from the received beacon signal and outputs corresponding pointing errors to the APM controller and to a VAP element controller. The antenna reflector is illuminated by radiating feed elements configured as a phased array that produces, in a far field of the reflector, a set of user beams. The APM controller causes the APM to adjust the reflector pointing, at a frequency less than f1, to reduce the measured pointing errors. The VAP element controller adjusts pointing of the user beams by adjusting beam forming coefficients of the VAP adjusting arrangements at a second frequency greater than f1.

Abstract: A spacecraft includes a payload subsystem including a plurality of transmit antenna feeds, a digital channelizer, and a power amplification arrangement including a plurality of power amplifiers. The power amplification arrangement has at least one input communicatively coupled with an output of the digital channelizer and at least one output communicatively coupled with at least one of the plurality of transmit antenna feeds. A processor is configured to control the digital channelizer, and to adjust a saturated output power of at least one power amplifier of the plurality of power amplifiers in the power amplification arrangement.

Abstract: An imaging array fed reflector for a spacecraft is included in a spacecraft payload subsystem. The payload subsystem includes a multi-beam antenna including a reflector, a plurality of amplifiers, and a plurality of radiating feed elements, the feed elements configured as a phased array, illuminating the reflector, operable at a frequency having a characteristic wavelength (?), and configured to produce, in a far field at the reflector, a set of contiguous abutting beams. The amplifiers are disposed proximate to the plurality of radiating feed elements. Each radiating feed element has a respective coupling with at least one respective amplifier of the plurality of amplifiers. Each radiating feed element, together with the at least one respective amplifier, is disposed in a closely packed triangular lattice such that separation between adjacent radiating feed elements is not greater than 1.5?.

Abstract: A spacecraft includes a payload subsystem, the payload subsystem including a phased array of feed elements configured to illuminate an antenna reflector, a beam forming network (BFN) disposed proximate to the array of feed elements, and a plurality of power amplifiers disposed between the BFN and the array of feed elements. The BFN includes a plurality of variable amplitude and phase adjusting arrangements disposed between (i) m:1 power combiners that are communicatively coupled with the power amplifiers and (ii) at least one 1:n power splitter, where m is greater than 1, and n is greater than 2.

Abstract: An imaging array fed reflector for a spacecraft is included in a spacecraft payload subsystem. The payload subsystem includes a multi-beam antenna including a reflector, a plurality of amplifiers, and a plurality of radiating feed elements, the feed elements configured as a phased array, illuminating the reflector, operable at a frequency having a characteristic wavelength (?), and configured to produce, in a far field at the reflector, a set of contiguous abutting beams. The amplifiers are disposed proximate to the plurality of radiating feed elements. Each radiating feed element has a respective coupling with at least one respective amplifier of the plurality of amplifiers. Each radiating feed element, together with the at least one respective amplifier, is disposed in a closely packed triangular lattice such that separation between adjacent radiating feed elements is not greater than 1.5?.

Abstract: A spacecraft includes a payload subsystem including a plurality of transmit antenna feeds, a digital channelizer, and a power amplification arrangement including a plurality of power amplifiers. The power amplification arrangement has at least one input communicatively coupled with an output of the digital channelizer and at least one output communicatively coupled with at least one of the plurality of transmit antenna feeds. A processor is configured to control the digital channelizer, and to adjust a saturated output power of at least one power amplifier of the plurality of power amplifiers in the power amplification arrangement.

Abstract: A spacecraft includes a payload subsystem, the payload subsystem including a phased array of feed elements configured to illuminate an antenna reflector, a beam forming network (BFN) disposed proximate to the array of feed elements, and a plurality of power amplifiers disposed between the BFN and the array of feed elements.

Abstract: A spacecraft includes a payload subsystem, the payload subsystem including a phased array of feed elements configured to illuminate an antenna reflector, a beam forming network (BFN) disposed proximate to the array of feed elements, and a plurality of power amplifiers disposed between the BFN and the array of feed elements.

Abstract: A spacecraft has a high efficiency multi-beam antenna (MBA) system that serves a coverage region on the Earth. The coverage region subtends an angle, when viewed from the spacecraft, of at least ten degrees. The antenna system provides, within the coverage region, at least sixteen spot beams. A signal provided by the MBA system to each spot beam has a carrier to interference ratio (C/I) of no less than 20 dB. The system enables use of a three color frequency reuse scheme without recourse to signal encoding.

Abstract: A broadband satellite having a payload subsystem configured to provide dual frequency conversion and bandwidth aggregation is communicatively coupled (i) to at least one gateway by a feeder link operating at a first frequency band; and (ii) to a plurality of user terminals by user links operating at a second frequency band. The payload subsystem has a first and a second frequency converter a satellite feeder link antenna feed, and a satellite user link antenna feed. The first frequency converter down converts, to a third frequency band, as an aggregated block, signals received at the satellite feeder link antenna feed from the gateway via the feeder link. The third frequency band is substantially lower than both the first and second frequency band. The down converted signals are routed to the second frequency converter for up converting to the second frequency band for transmission over the user link to the user terminals.

Abstract: A spacecraft has a high efficiency multi-beam antenna (MBA) system that serves a coverage region on the Earth. The coverage region subtends an angle, when viewed from the spacecraft, of at least ten degrees. The antenna system provides, within the coverage region, at least sixteen spot beams. A signal provided by the MBA system to each spot beam has a carrier to interference ratio (C/I) of no less than 20 dB. The system enables use of a three color frequency reuse scheme without recourse to signal encoding.

Abstract: A broadband satellite having a payload subsystem configured to provide dual frequency conversion and bandwidth aggregation is communicatively coupled (i) to at least one gateway by a feeder link operating at a first frequency band; and (ii) to a plurality of user terminals by user links operating at a second frequency band. The payload subsystem has a first and a second frequency converter a satellite feeder link antenna feed, and a satellite user link antenna feed. The first frequency converter down converts, to a third frequency band, as an aggregated block, signals received at the satellite feeder link antenna feed from the gateway via the feeder link. The third frequency band is substantially lower than both the first and second frequency band. The down converted signals are routed to the second frequency converter for up converting to the second frequency band for transmission over the user link to the user terminals.

Abstract: 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.

Abstract: An efficient multi-beam antenna system for use with a high capacity communications satellite or spacecraft that maximizes frequency re-use of the allocated frequency spectrum. The antenna system has first and second offset reflectors disposed adjacent first and second sides of the spacecraft. A first plurality of the feed horns feed the first reflector, and a second plurality of the feed horns feed the second reflector. The feed horns and offset reflectors cooperate to produce a predetermined number of beams. Even numbered beams use a set of frequencies and polarizations that are orthogonal to a set of frequencies and polarizations used by odd numbered beams. The antenna beams are contiguous in one dimension.