Abstract: Provided herein is a deployable antenna assembly, a method of deploying an antenna, and systems and methods for sequentially deploying an extendable structure. The deployable antenna assembly includes an extendable pillar configured to extend in an axial direction along a deployment axis of the deployable antenna assembly to deploy an antenna. The extendable pillar includes at least one extendable element configured to convert between a stowed configuration and a deployed configuration where the deployed configuration is longer in the axial direction than the stowed configuration. The extendable pillar also includes a launcher configured to initiate conversion of the plurality of extendable elements from the stowed configuration to the deployed configuration, thereby extending the extendable pillar and deploying the antenna.

Abstract: A deployable aperture reflector for use in antennas to reflect an RF electromagnetic signal of a predetermined signal frequency band includes a deployable aperture structure deployable between a stowed aperture configuration and a deployed aperture configuration. The aperture structure includes a plurality of rigid members connecting to one another to support an RF reflective assembly when in the deployed aperture configuration. The RF reflective assembly includes a plurality of faceted cells adjacent one another that form an assembly mechanical shape approximating an optimal desired electrical surface shape. Each faceted cell includes at least one layer carrying RF resonant elements thereon that electrically compensate a difference between the assembly mechanical shape and the optimal desired electrical surface shape.

Abstract: A node and a strut connect to one another to form a spaceframe structure, in which the strut has a strut bending stiffness and defines a strut axis. The node has a main body and an arm connecting to and extending from the main body along the strut axis and toward the strut. The arm has a node end attaching to the main body, a strut end connecting to the strut and a midsection extending there between. The midsection includes a neck portion having a neck bending stiffness being less than 20% of the strut bending stiffness. The strut includes primary and secondary sections that axially slidably connect to one another to position them between adjacent respective end-fittings of adjacent nodes, and partially axially overlap and secure to one another and to the end-fittings respectively. At least one of the end-fittings connects to the strut end of the arm.

Abstract: A heat exchanger includes a core portion and at least one substantially straight header plate. The core portion includes a plurality of heat exchanger tubes and fins disposed alternatively.

Abstract: A parasitic element for a helical antenna having at least one helix conductor extending from a secured first longitudinal end of the antenna to an opposite free second longitudinal end thereof around an antenna major-axis. The parasitic element includes an electrically conductive ring located adjacent and spaced apart from the second end in a direction leading away from the first end with the ring axis being parallel to and substantially collinear with the antenna major-axis. The ring has an outer diameter substantially equal to the diameter of the helix conductor at the second end.

Abstract: A parasitic element for a helical antenna having at least one helix conductor extending from a secured first longitudinal end of the antenna to an opposite free second longitudinal end thereof around an antenna major-axis. The parasitic element includes an electrically conductive ring located adjacent and spaced apart from the second end in a direction leading away from the first end with the ring axis being parallel to and substantially collinear with the antenna major-axis. The ring has an outer diameter substantially equal to the diameter of the helix conductor at the second end.

Abstract: A helical antenna has a helix supported by a helix support. The helix support includes at least one piece of flexible sheet having its two surfaces covered with a layer antistatic material. The flexible sheet is curlable into a revolution surface configuration to form a revolution surface-shaped support section for at least partially supporting a portion of the helix component there around. A grounding mechanism electrically grounds the external sheet surface to the helix and the two sheet surfaces to one another when in the revolution surface configuration while a locking mechanism locks the flexible sheet in the revolution surface configuration. The combination of the helix and the flexible support renders the antenna structurally relatively rigid in all directions.

Abstract: A helical antenna has a helix supported by a helix support. The helix support includes at least one piece of flexible sheet having its two surfaces covered with a layer antistatic material. The flexible sheet is curlable into a revolution surface configuration to form a revolution surface-shaped support section for at least partially supporting a portion of the helix component there around. A grounding mechanism electrically grounds the external sheet surface to the helix and the two sheet surfaces to one another when in the revolution surface configuration while a locking mechanism locks the flexible sheet in the revolution surface configuration. The combination of the helix and the flexible support renders the antenna structurally relatively rigid in all directions.