Shape Memory Antenna Deployment via Thermal Actuation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current deployable dish antennae for satellites are impractical for smaller satellites due to size, weight, complexity, and mechanical interface requirements, leading to deployment issues and reduced reliability, with limited flexibility in storage and placement.
Innovation Solution
A shape memory-based deployable dish antenna that is formed into its deployed shape during manufacturing and restrained until deployment, using heat to return to its original shape for efficient storage and deployment without mechanical actuators, allowing for compact, lightweight, and energy-efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rigid permanent dish antennae are used, then antenna gain is improved, but weight and volume increase making them impractical for smaller satellites
Solution Approach 1:
The antenna dish is divided into multiple petal-shaped rigid elements that can be stowed in a compact stack configuration and deployed to form a paraboloid reflector. This segmentation allows the antenna to achieve high gain when deployed while maintaining low weight and compact volume during stowage, resolving the contradiction between antenna performance and satellite size constraints.
Solution Approach 2:
The antenna transitions from a static rigid structure to a dynamic deployable structure. The petal elements are designed to be movable, allowing the antenna to change from a compact stowed configuration to a deployed paraboloid shape in space. This dynamic capability enables the antenna to provide high gain only when needed, reducing the effective weight and volume burden on the satellite.
2Volume of moving object
If deployable dish antennae with mechanical deployment mechanisms are used, then compact stowage is improved, but device complexity and mechanical interface requirements increase
Solution Approach 1:
Traditional mechanical deployment mechanisms (gearing assemblies, cables, tensioners) are replaced with shape memory alloy actuators. These SMA actuators use thermal activation to produce mechanical motion, eliminating complex mechanical interfaces and reducing deployment mechanism complexity while maintaining compact stowage capability.
Solution Approach 2:
The deployment mechanism utilizes changes in the physical state of shape memory alloy materials. By controlling temperature parameters, the SMA actuators transition between martensite and austenite phases, producing the necessary mechanical motion for deployment without complex mechanical systems. This parameter-based control simplifies the overall device complexity.
3Stability of the object's composition
If complex three-dimensional lattice support structures are used, then deployed shape stability is improved, but weight and device complexity increase
Solution Approach 1:
Instead of heavy rigid three-dimensional lattice support structures, the invention uses a flexible reflective membrane that is attached to the petal elements. The membrane maintains the paraboloid shape through its flexibility and attachment to the deployed petal structure, significantly reducing weight while maintaining shape stability during operation.
4Reliability
If multiple mechanical deployment mechanisms are added, then deployment reliability is improved, but overall assembly weight and complexity increase
Solution Approach 1:
The invention replaces multiple mechanical deployment mechanisms with shape memory alloy actuators that use thermal activation. This substitution reduces the number of mechanical interfaces and moving parts, thereby reducing complexity while maintaining or improving deployment reliability through the inherent reliability of thermal-actuated materials.
5Volume of moving object
If antenna is positioned to conform to launch vehicle envelope, then storage efficiency is improved, but placement flexibility on satellite is reduced
Solution Approach 1:
The antenna's ability to dynamically transition between compact stowed and deployed configurations provides placement flexibility. During launch, the antenna can be positioned in various orientations within the launch vehicle envelope in a compact state. After deployment in space, it transitions to its functional paraboloid shape, allowing it to be positioned at various locations on the satellite without being constrained by launch vehicle geometry.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides high volumetric packing efficiency, reduced weight, simplified construction, improved reliability, and relaxed placement constraints, enabling reliable and efficient deployment in deep space environments.
Implementation Method 1
At deployment it is heated to—or above the phase—or glass transition temperature of the shape memory material, and returns to their original 'as-trained' shape.
Implementation Method 2
it is mechanically restrained in the deployed geometry while being heated at—or above the phase—or glass transition temperature of the shape memory material
Data Source
AI summary
Described are several embodiments of parabolic reflective antenna systems where rigid parabolic dishes based on shape memory materials are deployed to full size and shape from compact pre-folded preforms by application of heat. Several shape memory feeds working with the dishes are presented. Feed preforms include corrugated, telescopic and flattened ribbon types which extend or unfurl into final shapes upon application of heat. Several dish and feed embodiments also contain supports for secondary reflectors and patch antennas.