Abstract: A method, apparatus, article of manufacture, and a memory structure for generating reconfigurable beams is disclosed herein. The apparatus comprises a stationary feed array having a plurality of selectably activatable feed array elements, the feed array having a feed array sensitive axis; a reflector, illuminated by the selectably activatable feed array elements; a first mechanism, coupled to the reflector, for varying a position of the reflector along the feed array axis; wherein a desired beam size of the antenna system is selected by varying the reflector position along the feed array sensitive axis and by selectably activating the feed array elements.

Abstract: A hybrid reflector antenna particularly suited for reflecting a frequency band in a satellite includes a central portion fully reflective to the frequency band. A first annular band is disposed directly adjacent to the central portion. The first annular band is partially reflective to the frequency band. The reflector may include several annular bands having various degrees of reflectivity and thus attenuation. The present invention may be implemented using two such reflectors, one for transmitting and one for receiving in a satellite, for either single or multiple beam applications. This invention offers more compact and lower mass/cost antenna configurations compared to conventional antennas from multiple beam satellite payloads.

Abstract: A hybrid reflector antenna particularly suited for reflecting a frequency band in a satellite includes a central portion fully reflective to the frequency band. A first annular band is disposed directly adjacent to the central portion. The first annular band is partially reflective to the frequency band. The reflector may include several annular bands having various degrees of reflectivity and thus attenuation. The present invention may be implemented using two such reflectors, one for transmitting and one for receiving in a satellite, for either single or multiple beam applications. This invention offers more compact and lower mass/cost antenna configurations compared to conventional antennas from multiple beam satellite payloads.

Abstract: A dual-band multiple beam antenna system for a communications satellite sharing a set of reflector antennas for the transmit and receive frequencies. One set of reflectors is common to both the downlink and uplink frequencies. The feed horns are diplexed and exhibit frequency-dependent radiation patterns that separate the phase centers over the downlink and uplink frequency bands to obtain dual-band performance. The focal point of the reflector is in close proximity to the phase center corresponding to the downlink frequency band. The phase center for the uplink frequency band is spaced a predetermined distance from the phase center of the downlink frequency band. According to the present invention, the uplink frequencies are defocused and the downlink frequencies are focused thereby creating identical radiation patterns at both frequency bands and over the coverage region of the communications satellite.

Abstract: A method and system for reconfiguring an antenna system are disclosed. The system comprises a feed horn, a subreflector, and a main reflector. The feed horn is pointed at an axis removed from the bisector axis of the subreflector. The distance between the feed horn and the subreflector can be changed to defocus the feed horn with respect to the subreflector, wherein a size of the outgoing beam emanating from the main reflector changes when the distance between the feed horn and the subreflector is changed. The method comprises pointing an axis of a feed horn at a subreflector, wherein the axis of the feed horn is aligned differently from the bisector axis of the subreflector, and changing the distance between the feed horn and the subreflector to defocus the feed horn with respect to the subreflector, wherein a size of an outgoing beam emanating from a main reflector changes when the distance between the feed horn and the subreflector is changed.

Abstract: A satellite subsystem for a satellite employs a reconfigurable communications payload and active array antennas. The subsystem includes an active receive array antenna having a reconfigurable beam forming network for forming input beam signals from input signals received by the receive antenna from sources. An input switch matrix power divides the input beam signals into sets of input beam signals. Each of the channel signals corresponds to a respective channel of the input beam signals. The subsystem further includes a channelizer having a plurality of channel processors each receiving at least one input beam signal from the input switch matrix. The channel processors filter the input beam signals into channel signals. Each of the channel signals corresponds to a respective channel of the input beam signals. The channel processors change the frequency of at least one channel signal to route the at least one channel signal to a different channel than the respective channel of the input beam signals.

Abstract: An antenna configuration suitable for LEO/MEO satellites includes a plurality of lenses whereby each lens has a plurality of feed horns positioned with respect to the lens. The lens has a first surface and a second surface. The plurality of feed horns is disposed upon a curved surface. Each of the plurality of feed horns generates a beam that has a phase distribution. The phase distributions have a predetermined phase relationship with the first surface and preferably the second surface. This allows the lens to transmit and receive a signal with desired phase distribution across a cross-section of the beam. The beams from the plurality of lenses are inter-leaved on the ground to form a contiguous coverage with multiple overlapping spot-beams.

Abstract: A method and apparatus for forming satellite transmission beams are disclosed. A beamforming network in accordance with the present invention comprises an array of antennas and primary and secondary dividing networks. The array of antennas comprises at least a first subarray having a first number of elements and a second subarray having a second number of elements. The primary dividing network divides a beam signal into a plurality of panel signals, wherein a number of panel signals is substantially equal to a number of subarrays. The secondary dividing network divides a first panel signal into a first plurality of element signals substantially equal in number to the first number of elements and for dividing a second panel signal into a second plurality of element signals substantially equal in number to the second number of elements.

Abstract: An antenna configuration suitable for LEO/MEO satellites includes a plurality of lenses whereby each lens has a plurality of feed horns positioned with respect to the lens. The lens has a first surface and a second surface. The plurality of feed horns is disposed upon a curved surface. Each of the plurality of feed horns generates a beam that has a phase distribution. The phase distributions have a predetermined phase relationship with the first surface and preferably the second surface. This allows the lens to transmit and receive a signal with desired phase distribution across a cross-section of the beam. The beams from the plurality of lenses are inter-leaved on the ground to form a contiguous coverage with multiple overlapping spot-beams.

Abstract: A dual-linearly polarized multi-mode rectangular horn includes a step junction in each of the two orthogonal planes for producing a desired amount of the higher order TE.sub.30 mode signal along with the dominant order TE.sub.10 mode signal for both of the vertical and horizontal polarization signals. The rectangular horn further includes a phasing section in each of the two orthogonal planes for causing the TE.sub.30 mode signal to be a desired amount of degrees out of phase with the TE.sub.10 mode signal at the aperture plane of the rectangular horn for both of the vertical and horizontal polarization signals. The rectangular horn is for use in a reconfigurable satellite array antenna.

Abstract: A reconfigurable multiple beam phased array antenna has radiating elements arranged in a planar array and variable phase shifters. Each one of the phase shifters is connected to a respective one of the radiating elements. The array antenna further includes a beam forming network for forming spot and regional beam signals. The beam forming network forms a regional beam signal from a combination of spot beam signals. The beam forming network has two dimensional stacks of Rotman lenses provided with a first set of ports. Each one of the first set of ports is connected to a respective one of the radiating elements with. The Rotman lenses generate frequency invariant spot beam signals which are communicated between the radiating elements and the Rotman lenses via the first set of ports for transmission and reception of spot beams and regional beams by the radiating elements. The phase shifters are adjusted to steer the spot and regional beams to desired locations.

Abstract: A reconfigurable multiple beam array antenna for transmitting beams includes a reflector and radiating elements for feeding beam signals to the reflector. The array antenna includes a reconfigurable beam forming network having a plurality of dividers, a plurality of adjustable phase shifter and attenuator pairs, and a plurality of combiners to form beam signals from beam signals input to the beam forming network. A first hybrid matrix formed by an association of couplers is connected to the beam forming network for receiving the beam signals. Amplifiers receive and amplify the beam signals from the first hybrid matrix. A second hybrid matrix formed by an association of couplers is connected to the amplifiers for receiving the beam signals. The second hybrid matrix provides the amplified beam signals to the radiating elements for the reflector to transmit beams.