Antenna system includes an elongated antenna feed tower structure having a tower base at one end which includes a plurality of feet arranged to align with a plurality of predetermined structural mounting points associated with a space vehicle bus. The antenna system also includes a deployable reflector assembly comprising a hub ring. The hub ring includes a reflector deployment mechanism around which a plurality of reflector ribs are disposed. The hub ring is advantageously arranged to engirdle the feed tower assembly. As such, the central aperture is configured to receive the feed tower assembly therein after the feed tower has already been mounted to the space vehicle.

Antenna reflectors having a diameter of 10 or more meters include dimensionally and thermally stable deformable composite reflective material that enables efficient packaging of solid surface segmented reflectors and a folding scheme and architecture that enables self-deployment to support S-band and above RF (?2 GHz) transmissions.

Self-deploying reflector array architectures include stacked multiple panels attached to a central panel by sets of heat actuated flexible hinges on their non-functional sides create surface of revolution, cylindrical and flat reflector arrays in accordance with panel curvature. Robotic in-space assembly of multiple smaller arrays allows for creation of reflector array of 10 or more meters to support S-band and above RF (?2 GHz) transmission.

Self-deploying reflector array architectures include stacked multiple panels attached to a central panel by sets of heat actuated flexible hinges on their non-functional sides create surface of revolution, cylindrical and flat reflector arrays in accordance with panel curvature. Robotic in-space assembly of multiple smaller arrays allows for creation of reflector array of 10 or more meters to support S-band and above RF (?2 GHz) transmission.

The invention is a structure, comprising a first functional element (11) and a second functional element (12), said functional elements (11, 12) being form-retentive and being cooperatively functional in an operational state of the structure, in said operational state the functional elements (11, 12) having a predetermined relative spatial arrangement and being distanced from each other; a tension assembly (20) coupling the functional elements (11, 12) to each other, the tension assembly (20) being adapted to be taut in said operational state and being coupled to the first functional element (11) by respective first couplings and to the second functional element (12) by respective second couplings; the functional elements (11, 12), the couplings and the tension assembly (20) together forming a tensioned assembly; and a tensioning assembly (30) coupled to the tensioned assembly, the tensioning assembly (30) being adapted to exert a repulsive force distancing the first functional element (11) and the second functional element (12) for maintaining said operational state,
wherein the system compliance of the tensioned assembly is less than 60% of the system compliance of the tensioning assembly (30).

A corner reflector includes annular balloons, which, when gas is supplied to the inside, annularly expand, and radio wave reflective films each developed to a plane by the expansion of the annular balloons. The three annular balloons are provided so as to be orthogonal to each other in the expansion. A constraint fabric wound around each annular balloon is provided. The constraint fabric includes an inner peripheral side fabric portion located on the side of a virtual central axis of the annular balloon and extending in the annular direction around the virtual central axis, and an outer peripheral side fabric portion located on the side opposite to the virtual central axis and extending in the annular direction. The elongation degree of the outer peripheral side fabric portion in the annular direction is higher than the elongation degree of the inner peripheral side fabric portion in the annular direction.

A corner reflector includes annular balloons, which, when gas is supplied to the inside, annularly expand, and radio wave reflective films each developed to a plane by the expansion of the annular balloons. The three annular balloons are provided so as to be orthogonal to each other in the expansion. A constraint fabric wound around each annular balloon is provided. The constraint fabric includes an inner peripheral side fabric portion located on the side of a virtual central axis of the annular balloon and extending in the annular direction around the virtual central axis, and an outer peripheral side fabric portion located on the side opposite to the virtual central axis and extending in the annular direction. The elongation degree of the outer peripheral side fabric portion in the annular direction is higher than the elongation degree of the inner peripheral side fabric portion in the annular direction.

A reflector system includes a hoop assembly, a collapsible mesh reflector surface and an extendible mast assembly. The hoop assembly includes a plurality of link members extending between a plurality of hinge members and the hoop assembly is moveable between a collapsed configuration wherein the link members extend substantially parallel to one another and an expanded configuration wherein the link members define a circumferential hoop. The reflector surface is secured to the hoop assembly and collapses and extends therewith. The hoop is secured by cords relative to top and bottom portions of a mast that maintains the hoop substantially in a plane. The mast is stored on a spool and extends to release the hoop, pull the mesh reflector surface into a shape that is intended to concentrate RF energy in a desired pattern, and tension the cords that locate the hoop.

Apparatus for improving the performance and allowing increased directionality of reflecting-type antenna systems by varying the geometry of the reflecting surface. A reflecting surface is composed of an array of actuated pins which are capable of extending or retracting to alter the overall pattern. An actuator controlling unit has the address of each actuator and is able to extend or retract the pins to the desired degree. The specific pattern which the actuator control unit realizes is determined by the iterative position calculator which utilizes directional inputs from the user and/or inputs from a system which determines the effectiveness of previous pin movements. The apparatus attempts to maximize the received signal by assessing amplitude changes over time and utilizing that information to direct alteration in the reflecting surface for optimal performance.

An antenna system for satellite applications is provide, the antenna system comprising an antenna array and a feed structure, and the antenna array is a passive antenna array configured to have a first state and a second state, the second state being a first deployed state. The feed structure is configured to provide a linearly polarized incident field for the antenna array in the first deployed state. The antenna array comprises a plurality of array elements, and the plurality of array elements forms a polarization conversion surface configured for converting the linearly polarized incident field to a reflected/transmitted circular polarized field. The antenna array is configured so that the radiation pattern of the reflected/transmitted circular polarized field corresponds to a predetermined radiation pattern and an array element geometry and an array element position of each of the plurality array elements are configured to provide the predetermined radiation pattern.