Hughes Electronics Corporation

The Boeing Company

The Directv Group, Inc.

Steven O Lane

Harold A Rosen

Robert E Vaughan

James D Thompson

Arnold L Berman

Todd K Citron

Parthasarathy Ramanujam

Victor S Reinhardt

James M Barker

Louis W Hendrick

Philip H Law

Douglas T Bell

Michael J Grall

James C McCleary

William F Davis

Bruce A Tomei

Kary L O'Connor

Brian T Sleight

William C Faherty

An improved satellite communication device and system are provided. The satellite communication device uses yaw or roll-yaw steering to linearize angular track of uplink cells; one-dimensional linear 'ratcheting' in an uplink antenna to maintain resource allocation of uplink cells along antenna columns; phased-array downlink antennas which can track earth-fixed downlink cells while compensating for the yaw (or roll-yaw) satellite steering; and variable rate TDMA service among downlink cells in a footprint. As a result, system overhead for performing new resource allocations between satellite handovers is minimized, thereby reducing resource management and increasing system capacity. Flexible bandwidth/capacity assignment of both uplink and downlink resources to earth locations via linear cell ratcheting, uplink RF peaking switch, and data-driven variable-TDMA downlink phased-arrays, is provided.

Satellite communication system using linear cell tracking

An amplifier redundancy system includes an amplifier receiving signals from a first input switch when the switch is in a side port position. The system further includes a first output switch, in a side port position, receiving signals from the amplifier. A second amplifier receives signals from the first input switch through a second input switch and generates amplified signals therefrom. The second input switch also receives signals from the first input switch when the first input switch is in the side port position. The first input switch is initially in the side port position but switches to a through port position in response to a failure in the second amplifier. A second output switch is in a through port position and switches to a side port position and receives signals through the first output switch in response to the failure in the second amplifier.

Gain and phase balanced amplifier redundancy system

A system and method for adjusting satellite communication signal transmit power for signals transmitted to a localized region within a satellite coverage area utilize real-time information on weather conditions ( ) and/or actual path losses ( ) within the localized regions to adjust the effective isotropic radiated power (EIRP) of the satellite beams ( ) to minimize the total radio frequency (RF) power required for transmission. The transmission system may be realized using a variety of antenna types for transmitting spot beams and/or area coverage beams. Representative antenna implementations include multi-beam antennas having a low-level beamforming network and hybrid matrix amplifier system, phased-array with independent input amplitude control and beamsteering for each beam, and a phased-array feeding a confocal imaging system for single broadcast beam per polarization. The present invention allows for the reduction of RF transmit power to achieve the same communications performance enabling either increases in satellite functionality and/or an increase in total capacity of the satellite communication system.

Satellite transmission system with adaptive transmission loss compensation

An antenna for scanning beams in only one common angular direction or angular path includes feed elements each providing a component beam and fixed beam combiners for combining the component beams into fixed beams. The fixed beam combiners combine the component beams in a first angular direction to form the fixed beams. Variable beam combiners combine the fixed beams into scanning beams. The variable beam combiners combine the fixed beams into the scanning beams to scan the scanning beams in a second common angular direction.

Low sidelobe antenna with beams steerable in one direction

An improved satellite communication device and system are provided. The satellite communication device uses yaw or roll-yaw steering to linearize angular track of uplink cells; one-dimensional linear &ldquo;ratcheting&rdquo; in an uplink antenna to maintain resource allocation of uplink cells along antenna columns; phased-array downlink antennas which can track earth-fixed downlink cells while compensating for the yaw (or roll-yaw) satellite steering; and variable rate TDMA service among downlink cells in a footprint. As a result, system overhead for performing new resource allocations between satellite handovers is minimized, thereby reducing resource management and increasing system capacity. Flexible bandwidth/capacity assignment of both uplink and downlink resources to earth locations via linear cell ratcheting, uplink RF peaking switch, and data-driven variable-TDMA downlink phased-arrays, is provided.

A satellite antenna pointing system has a reflector antenna for receiving an uplink signal from an earth based ground station and a satellite based phased array assembly for transmitting a downlink signal. Because extraterrestrial communications suffer significant losses during transmission, accurate pointing of both uplink and downlink antennas is desired in order to reduce required signal strength. The present invention uses two different methods for pointing the uplink and downlink antennas.

Satellite antenna pointing system

An antenna system and method for generating a desired contiguous spot beam pattern, and a signal is disclosed. The contiguous spot beam generating antenna system comprises a reflector system configured in a side-fed Cassegrain (SFOC) configuration, an array of feed horns comprising at least a subset of feed horns for illuminating the reflector system, and a beamforming network, communicatively coupled to the array of feed horns, for controlling an excitation of the subset of the feed horns in the array of feed horns. The method comprises illuminating a side fed offset Cassegrain reflector system with an RF signal emanating from an array of feed horns, and controlling an excitation of the subset of the feed horns. The present invention provides a beamformer network that can produce uniform performance over wide scan angles, is easier to integrate and test, that can change the beam pattern on orbit, and that provides a more complete utilization of space assets without dramatically increasing the cost of manufacturing and operating a satellite. The use of a SFOC configuration or other wide scanning antenna permits the use of a simple beamforming network while maintaining excellent beam beam scanning characteristics.

Multi-beam reflector antenna system with a simple beamforming network

A multiple beam phased array includes a plurality of array elements partitioned into a plurality of array element groups for forming a plurality of beams wherein each array element group has a taper center located to minimize maximum array element power for the plurality of beams.

Multiple beam phased array with aperture partitioning

A beam-forming network having a network of phase shifting devices that is independent from other parts of the beam-forming network. In one embodiment, the network of phase shifting devices has multiple layers between the power divider and power combiner layers. The multiple layers provide a selectable phase shift for each feed independent from the other feeds. In another embodiment, the network of phase shifting devices is one layer of commendable phase shifters. In any embodiment, the resulting composite beam has higher directivity and lower side lobes as compared to conventional beam-forming networks.

Beam forming network incorporating phase compensation

A radiating element for an antenna incorporating a patch launcher, a bandpass filter and a polarizer all in one waveguide without the need for interconnecting individual components. The waveguide has at least one coaxial input having a patch launcher attached thereto. The inside diameter of the waveguide has a plurality of spaced apart irises that act as a bandpass filter followed by a plurality of spaced apart pins that act as a polarizer.

Antenna radiating element

A communication and tracking antenna is formed by embedding a tracking patch array in a shaped dual gridded reflector. The reflector includes first and second reflector grids that have orthogonally arranged grid lines and are respectively fed by feed horns. The patch array is positioned so that the first reflector grid is between the patch array and the first feed horn. The first reflector grid thus serves as a filter to remove unwanted polarization components and enhance the quality of both the tracking radiation and the radiation that is reflected from the second reflector grid. In other embodiments, a tracking array is positioned adjacent a reflector's perimeter.

Communication and tracking antenna systems for satellites

An active redundancy system for high power satellite communications payloads that use multiple antenna beams driven by multiple power amplifiers and that require power redistribution among the beams during the lifetime of a payload uses a number of power amplifiers equal to or greater than the number of antenna feeder elements to provide extra output power at the beginning of life, instead of commonly used redundancy switches. As power amplifiers fail, the amplitude and phase of the signals driving the remaining power amplifiers are adjusted to maintain antenna performance. Power amplifiers having sufficient capacity are used to ensure that, given an anticipated number of power amplifier chain failures, performance requirements can be met at the end of life.

Satellite communications apparatus using active redundancy

A communication payload system for a satellite having a beam forming network, an amplifier associated with each output port of the beam forming network, and a plurality of hybrid matrices and a calibration pick-up antenna. Each hybrid matrix has a plurality of inputs connected to selected amplifiers and a corresponding number of outputs. One output of each hybrid matrix is connected to a power absorber adapted to function as an output calibration port producing a calibration sample and the remaining outputs connected to feed radiating elements. A calibration system applies power to selected output ports and calculates calibration corrections in response to the values of the calibration samples and the values of the power radiated by each feed radiating element which are applied to the beam forming network to maintain the calibration of the payload system.

Calibration method for satellite communications payloads using hybrid

A phased array antenna (10A, 10B, 10C) is constructed of an array of radiators (24), each of which has a radiating aperture, a first port (26) and a second port (26). The first port introduces a first radiation with a first polarization, and the second port introduces a second radiation with a second polarization which is orthogonal to the first polarization. Individual transmitting amplifiers, in the case of a transmitting array, or individual receiving amplifiers (16A), in the case of a receiving array, are connected to the ports of each of the radiators. The amplifiers associated with the first ports of the respective radiators are connected, in turn, to phase shifters (18A) and attenuators (20A) which constitute a first beamformer for forming a set of one or more beams of radiation. The amplifiers (16A) associated with the second ports of the respective radiators are connected, in turn, to phase shifters (18A) and attenuators (20A) which constitute a second beamformer for forming a set of one or more beams of radiation. The two beamformers operate independently of each other so as to permit separately weighted polarization signals of the antenna to be programmed electronically for various polarizations such as right and left circular polarization or horizontal and vertical polarization. Also, the separately polarized waves associated with the first ports and the second ports permit dual polarization frequency reuse transmission.

Growing community of inventors

Rolling Hills Estates, CA, United States of America

Steven O Lane