Antenna apparatus and spacecraft to be deployed in a more easily stored state are disclosed. In an example of the disclosed technology, and antenna apparatus includes: a main-reflection unit including a plurality of ribs formed to be deployable in a stored state in which the ribs are folded and a sheet body provided between a plurality of the ribs and configured to be capable of reflecting a radio wave radiated from a radiator and emitting the radio wave outside, and a restriction member configured to restrict deployment of the plurality of ribs in the stored state, and release the restriction by operation of a restriction release member different from the main-reflection unit.

An antenna having a reflector mounted on a rigid boom uses a line feed or phased array feed to operate in the Ka band with frequencies up to 36 gigahertz while maintaining the ability to operate at frequencies down to L-Band of 1-2 GHz.

An outer space deployable antenna may include a support shaft, a plurality of antenna fins, and an actuator. At least one draw cord may be coupled between the antenna fins and the actuator so that the antenna fins are moveable from a flat stored configuration to a fanned-out deployed configuration surrounding the support shaft.

An expandable antenna includes: a plurality of ribs arranged with a regulated angular pitch at an outer circumferential portion of a hub; and a metal mesh installed between the plurality of adjacent ribs, wherein each of the plurality of ribs is formed in a horizontally elongated thin flat plate shape with elasticity, and a segment to which the metal mesh is attached is formed in a parabolic shape. A flat plane of each of the plurality of ribs is arranged so as to be substantially parallel to a central axis of the hub. The object of the present invention is to provide the expandable antenna which can be easily expanded in outer space with a simple structure and can realize a desired shape after expansion.

An expandable antenna includes: a plurality of ribs arranged with a regulated angular pitch at an outer circumferential portion of a hub; and a metal mesh installed between the plurality of adjacent ribs, wherein each of the plurality of ribs is formed in a horizontally elongated thin flat plate shape with elasticity, and a segment to which the metal mesh is attached is formed in a parabolic shape. A flat plane of each of the plurality of ribs is arranged so as to be substantially parallel to a central axis of the hub. The object of the present invention is to provide the expandable antenna which can be easily expanded in outer space with a simple structure and can realize a desired shape after expansion.

A reflector antenna apparatus includes: a radiator that emits a radio wave; a reflector that reflects the radio wave emitted from the radiator, a shape of the reflector being changeable; a support structure supporting the reflector, the support structure being connected to at least a part of an outer periphery of the reflector and including at least two flexible support members capable of following a change in the shape of the reflector; an injection device that injects a fluid into the at least two support members; and a coupling that couples the reflector and the at least two support members. In a deployed state in which the at least two support members are filled with the fluid, the reflector is configured to form a curved surface shape in which the reflector is not curved in a first direction and is curved in a second direction orthogonal to the first direction.

An antenna having a reflector mounted on a rigid boom uses a line feed or phased array feed to operate in the Ka band with frequencies up to 36 gigahertz while maintaining the ability to operate at frequencies down to L-Band of 1-2 GHz.

Deployable reflectors and antennas and spacecraft using such reflectors are disclosed. An example disclosed reflector includes: a hub having a cross-section formed in a circular, elliptical or polygonal shape; a plurality of ribs, each rib having an inner side surface facing an outer peripheral side of the hub when folded, and an outer side surface that is a surface opposite to the inner side surface, the plurality of ribs being folded to be wound around an outer periphery of the hub such that the inner side surface of each rib and the outer side surface of its adjacent rib partially face each other or the outer side surface of each rib and the inner side surface of its adjacent rib partially face each other, each rib being deployed in a parabolic shape; and a sheet installed across each of the plurality of ribs and capable of reflecting radio waves.

Deployable reflectors and antennas and spacecraft using such reflectors are disclosed. An example disclosed reflector includes: a hub having a cross-section formed in a circular, elliptical or polygonal shape; a plurality of ribs, each rib having an inner side surface facing an outer peripheral side of the hub when folded, and an outer side surface that is a surface opposite to the inner side surface, the plurality of ribs being folded to be wound around an outer periphery of the hub such that the inner side surface of each rib and the outer side surface of its adjacent rib partially face each other or the outer side surface of each rib and the inner side surface of its adjacent rib partially face each other, each rib being deployed in a parabolic shape; and a sheet installed across each of the plurality of ribs and capable of reflecting radio waves.

The example non-limiting technology herein provides a Synthetic Aperture Radar (SAR) solution on board a micro-satellite that provides global revisit within 1 month; a cost below US$ 10 million; and satellite mass lower than 100 kg. One solution uses an inflatable Cassegrain type antenna with a phased beam steering array in the 1.2 GHz band.