CNT Sheet Reflector Folding for High-Frequency Deployable Antennas

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Solution Overview

Problem

Conventional reflector antenna systems face challenges with Au/Mo mesh degrading at higher frequencies, weight, and cost, along with design issues in stowage and deployment of alternative materials.

Innovation Solution

A deployable reflector system using a carbon nanotube (CNT) sheet with a predetermined folding pattern, secured to a support structure, transitions from a compact stowed to a larger deployed configuration, enabling automatic extension and forming a smooth concave or parabolic shape.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If Au/Mo mesh is used for reflector surface, then reflector can be made with conventional structure, but performance degrades at higher frequencies and weight and cost increase

Engineering Contradiction:
Improvereflector performance at higher frequenciesVSAvoidreflector weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent changes the material parameter from conventional Au/Mo mesh to carbon nanotube (CNT) sheet, which maintains high reflectivity at higher frequencies while significantly reducing weight. The CNT sheet's unique electromagnetic properties enable superior performance in Ka-band and higher frequency applications compared to traditional mesh materials.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses carbon nanotube sheet as a composite material that combines the reflective properties needed for antenna applications with the mechanical flexibility required for deployable structures. The CNT material provides both electromagnetic functionality and structural adaptability in a single integrated component.

Inventive Principle:
Principle #40Composite materials

2Volume of moving object

If reflector structure is made collapsible for stowage, then compact storage is achieved, but deployment complexity increases

Engineering Contradiction:
Improvestowage volumeVSAvoiddeployment mechanism complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The patent implements a dynamically deployable structure where the support framework can transition between collapsed and expanded configurations. The structure uses movable joints and flexible connections that allow automatic deployment through simple actuation, reducing the complexity of deployment mechanisms while achieving compact stowage.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent nests the CNT sheet reflector within the collapsible support structure during stowage, with the reflector folded and contained within the compact framework. When deployed, the structure expands outward, automatically unfolding and positioning the reflector surface in its functional configuration.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Reliability

If CNT sheet is used for reflector surface, then performance at higher frequencies improves and weight reduces, but stowage and deployment design becomes more challenging

Engineering Contradiction:
Improvereflector performance at higher frequenciesVSAvoidstowage and deployment design
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs the CNT sheet as a flexible thin film that can be folded and conform to the collapsible support structure during stowage. The material's flexibility allows it to be packaged in a compact form factor while maintaining its reflective properties, and it automatically returns to its functional shape when the structure is deployed.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent pre-configures the CNT sheet with fold lines and attachment points that enable automatic deployment. The sheet is preliminarily folded along predetermined patterns and secured to the support structure at specific locations, so that when the structure expands, the reflector automatically unfolds into its correct functional configuration without requiring additional actuation.

Inventive Principle:
Principle #10Preliminary action

4Weight of moving object

If conventional mesh materials are replaced with alternative materials, then weight and cost may be reduced, but stowage and deployment methods become more difficult

Engineering Contradiction:
Improvereflector weightVSAvoidstowage and deployment ease
Core Design Contradiction:
Weight of moving objectVSEase of operation

Solution Approach 1:

The patent designs the CNT sheet reflector to be self-deploying through its integration with the collapsible support structure. As the support framework expands from its collapsed to deployed configuration, the tension and geometric constraints automatically unfold the CNT sheet into its functional shape, eliminating the need for separate deployment mechanisms or manual intervention.

Inventive Principle:
Principle #25Self-service

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

Improves cross-polarization performance at higher frequencies, reduces weight, and lowers reflector costs while facilitating compact stowage and efficient deployment.

Implementation Method 1

The reflector surface is comprised of a carbon nanotube (CNT) sheet which is highly reflective of electromagnetic waves

Methodology Applied
Scientific EffectElectromagnetic reflection: Reflection

Implementation Method 2

The unfolding operation occurs when a tension force is applied to at least a portion of the CNT sheet by the support structure

Methodology Applied
Scientific EffectTension: Tension

Data Source

PatentEP4235968B1Deployable antenna reflector
Publication Date: 2025.07.02 EAGLE TECHNOLOGY LLC
  • EP4235968B1 patent drawingFigure 1
  • EP4235968B1 patent drawingFigure 2
  • EP4235968B1 patent drawingFigure 3

AI summary

Deployable reflector system includes a support structure and a reflector surface secured to the support structure. The support structure transition from a compact stowed configuration to a larger deployed configuration to deploy the reflector surface. The reflector surface is comprised of a carbon nanotube (CNT) sheet having a solid non-mesh surface. The sheet is intricately folded in accordance with a predetermined folding pattern to define a compact folded state. This predetermined folding pattern is configured to permit automatic extension of the CNT sheet from a compact folded state to a fully unfolded state. The unfolding operation occurs when a tension force is applied to at least a portion of the peripheral edge of the CNT sheet. In some scenarios, the support structure can comprise a circumferential hoop.