A multiple-feed antenna system includes a first feed configured to communicate signals in a first frequency range of a plurality of frequency ranges and a second feed configured to communicate signals in a second frequency range of the plurality of frequency ranges. A subreflector assembly is configured to move among multiple positions that include a first position and a second position. When the subreflector assembly is in the first position, a first element of the subreflector assembly redirects a signal reflected by a primary reflector to the first feed. When the subreflector assembly is in the second position, a second element of the subreflector assembly redirects the signal reflected by the primary reflector to the second feed.

A satellite-communications gateway includes a hub and an antenna configured for satellite communications. The antenna is mounted to the hub and supported by the hub. The antenna includes a plurality of panels forming a parabolic dish. The panels are carbon fiber-reinforce polymer. The parabolic dish has a diameter in a range of 9 to 13 meters.

A reflector for an antenna includes a first shaped region, wherein a curvature of the first shaped region is defined by a corresponding scan angle, and a second shaped region, wherein a curvature of the second shaped region is based on a corresponding scan angle. The curvature of the first shaped region is different than the curvature of the second shaped region.

Apparatus for dual-band antenna and communications tower comprising such apparatus are provided. The apparatus comprises a first part (202) comprising first and second propagation paths configured to selectively propagate signals of a first frequency with either a first polarization state or a second polarization state, a transition part (204) rotatable between first and second transition positions to selectively propagate signals of a second frequency along the second signal path with the first polarisation state when in the first transition position and with the second polarisation state when in the second transition position and a rotator part rotatable between first and second rotator positions. Wherein, the rotator part is configured to orientate the polarisation of signals in the second signal path in order to couple the second signal path to an interface, and allow propagation of signals in the first signal path in either the first or second rotator positions.

A method for providing frequency selective surface zoning includes selecting a location for positioning a frequency selective surface (FSS) panel along a support arm of a reflector antenna system, and positioning a second feed horn on the support arm on an opposite side of the FSS panel. A number of unit cells are used to populate the FSS panel, and metallic patterns are formed on each unit cell. Multiple zones are subsequently defined on the surface of the FSS panel. Each zone is optimized for a predetermined range of incident angles.

[Problem] To provide a spacecraft having a more effective arrangement of amplifiers. [Solution] Provided is a spacecraft comprising: a main body having a housing space for housing an electronic device within; an oscillator configured to output a radio wave including a frequency in a predetermined frequency band; an amplifier disposed on an exterior of the main body so as to be exposed to space and configured to amplify the power of the radio wave output by the oscillator; and an antenna, disposed on the exterior of the main body, for emitting the radio wave to the outside at the power amplified by the amplifier.

A deployable antenna structure is provided that, in one embodiment, implements an offset feed, cylindrical parabolic antenna. The antenna structure employs a semi-rigid panel that can transition from a stowed state characterized by the retention of substantial strain energy to a deployed state characterized by less strain energy than in the stowed state but more than if the panel were in a strain-free state and a portion of the panel having a shape that closely conforms to a cylindrical parabolic shape.

A deployable antenna structure is provided that, in one embodiment, implements an offset feed, cylindrical parabolic antenna. The antenna structure employs a semi-rigid panel that can transition from a stowed state characterized by the retention of substantial strain energy to a deployed state characterized by less strain energy than in the stowed state but more than if the panel were in a strain-free state and a portion of the panel having a shape that closely conforms to a cylindrical parabolic shape.

The antenna uses X Band frequencies for long-distance weather monitoring and W Band frequencies for imaging of terrain and obstacles, for use in a radar system in aircraft nose radome to operate effectively in a degraded visual environment. The antenna's feed structure includes concentrically positioned first and second horns. First and second rectangular waveguides are positioned on a cylindrical portion of the first horn, and at a first and second radial positions spaced 90 degrees apart. First and second coaxial cables respectively couple the first and second rectangular waveguides to a polarization converter, which launches linearly polarized waves received from each of the first and second coaxial cables to form a W-hand circularly polarized wave. The feed structure collects and disseminates W Band and X Band electromagnetic energy.

Microwave antenna systems include a parabolic reflector antenna and a dual-band feed assembly. The dual-band feed assembly includes a coaxial waveguide structure and a sub-reflector. The coaxial waveguide structure includes a central waveguide and an outer waveguide that circumferentially surrounds the central waveguide. The sub-reflector is mounted proximate the distal end of the coaxial waveguide structure.