Deployable antenna assembly and system and method for deploying an extendable structure

A system for a deployable antenna assembly, the system comprising:

• a plurality of extendable elements, wherein each extendable element is configured to:
• connect with another extendable element to form an extendable pillar, wherein the extendable pillar is configured to extend in an axial direction along a deployment axis;
• and
• convert between a stowed configuration and a deployed configuration, wherein each of the extendable elements in a deployed configuration is longer in the axial direction than an extendable element in a stowed configuration;
• a retaining device for retaining each extendable element in the stowed configuration in which extension of the respective extendable element is constrained and the respective extendable element stores potential energy that is releasable to extend the respective extendable element along the deployment axis, the retaining device comprising:
• a launch tube disposed within the extendable pillar along the deployment axis;
• an inner shaft disposed in the launch tube;
• and
• a plurality of ball bearings;
• wherein, for each extendable element in the stowed configuration, a subset of the ball bearings contacts and prevents deployment of the extendable element in the axial direction;
• and
• wherein movement of the inner shaft relative to the launch tube displaces the subset of ball bearings such that the respective extendable element is no longer constrained by the subset of ball bearings and extends in the axial direction via release of the stored potential energy;
• and
• a helical radiating element configured to:
• connect, directly or indirectly, to the extendable pillar;
• extend an extendable section of the helical radiating element, wherein the extendable section is translated in the axial direction along the deployment axis upon the extension of the extendable pillar in the axial direction;
• and
• transmit or receive a radio frequency (RF) signal.

A method of deploying an antenna, the method comprising:

• providing 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 comprising:
• at least one extendable element configured to convert between a stowed configuration and a deployed configuration, wherein the extendable element in a deployed configuration is longer in the axial direction than the extendable element in a stowed configuration;
• retaining, via a retaining device, each extendable element in the stowed configuration in which extension of the respective extendable element is constrained and the respective extendable element stores potential energy that is releasable to extend the respective extendable element along the deployment axis, the retaining device comprising:
• a launch tube disposed within the extendable pillar along the deployment axis, an inner shaft disposed in the launch tube, and a plurality of ball bearings;
• wherein, for each extendable element in the stowed configuration, a subset of the ball bearings contacts and prevents deployment of the extendable element in the deployment direction;
• and
• actuating the inner shaft relative to the launch tube to displace the subset of ball bearings such that the respective extendable element is no longer constrained by the subset of the ball bearings and extends in the deployment direction via release of the stored potential energy.