Composite Antenna Reflector with Segmented Fiber Sectors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current technologies for manufacturing small-diameter reflectors for telecommunications satellites in high frequency bands face challenges such as complexity, high cost, weight issues, and temperature compatibility, particularly in achieving the required precision and stability for space applications.
Innovation Solution
A reflector design using a superposition of fiber composite material layers with angular sectors oriented in specific directions, where each sector has a unique angle relative to the radial direction, forming a stiffening crown integrated into the reflector, reducing the need for multiple molds and cold bonding, and utilizing a single composite material for thermal stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If thick shell technology with sandwich structure is used, then manufacturing precision and structural rigidity are improved, but device complexity and production cost increase significantly
Solution Approach 1:
The reflector is divided into multiple angular sectors that can be manufactured separately and then assembled. Each sector is made using simple open molding techniques, avoiding the complex closed molding required by thick shell technology. The sectors are joined using friction stir welding, a simple solid-state welding process that does not require complex assembly fixtures or large quantities of adhesive.
Solution Approach 2:
The reflector uses composite materials (such as carbon fiber reinforced plastics) that provide both the required structural rigidity and lightweight properties. The composite material structure achieves the necessary mechanical strength and dimensional stability without requiring the complex sandwich construction of thick shell technology, thereby reducing assembly complexity while maintaining manufacturing precision.
2Strength
If thick shell technology with sandwich structure is used, then structural rigidity is improved, but weight increases beyond space application objectives
Solution Approach 1:
The reflector employs composite materials such as carbon fiber reinforced plastics that provide exceptional strength-to-weight ratio. These materials achieve the required structural rigidity and resonance frequency (>60Hz) while keeping the mass below 400g for a 500mm diameter reflector, meeting the stringent weight objectives for space applications that thick shell technology cannot achieve.
Solution Approach 2:
The reflector structure incorporates localized reinforcement elements such as ribs or stiffeners in specific areas where additional rigidity is needed, rather than uniformly thickening the entire structure. This allows the reflector to achieve required structural performance with minimum weight by placing material only where structurally necessary.
3Ease of manufacture
If metallic technology with machining is used, then manufacturing cost is reduced, but weight exceeds space application objectives
Solution Approach 1:
The reflector uses composite materials that can be formed using simple open molding techniques rather than expensive machining operations. This approach reduces manufacturing cost while simultaneously achieving the required weight objectives (<400g for 500mm diameter), as composites can be manufactured more efficiently and with less material waste than machined metal parts.
Solution Approach 2:
The manufacturing process transitions from subtractive machining (metallic technology) to additive/forming processes (composite molding). This parameter change in the manufacturing approach enables both cost reduction and weight reduction, as composite parts can be formed directly to shape with minimal material removal and lower processing costs.
4Strength
If Isogrid technology with reinforcement grid is used, then structural efficiency is improved, but assembly complexity and production cost increase
Solution Approach 1:
The reinforcement elements (ribs or stiffeners) are integrated directly into the reflector body during the molding process, merging the structural reinforcement function with the reflector structure itself. This eliminates the need for separate assembly steps to attach reinforcement grids, thereby reducing assembly complexity while maintaining structural efficiency. The friction stir welding process joins sectors with integrated reinforcement without requiring complex assembly fixtures.
Solution Approach 2:
The reflector is segmented into angular sectors that are manufactured separately using simple open molding and then joined using friction stir welding. This segmentation allows each sector to be produced independently with integrated reinforcement features, avoiding the need to assemble complex Isogrid reinforcement patterns across the entire reflector surface, thereby reducing overall assembly complexity.
5Weight of moving object
If monolithic technology with peripheral stiffener is used, then weight is reduced, but manufacturing process complexity increases due to multiple molds
Solution Approach 1:
The reflector is divided into angular sectors that can each be manufactured using simple open molding techniques. This segmentation eliminates the need for complex monolithic molds with integrated peripheral stiffeners, as each sector is formed independently using straightforward molding processes. The sectors are then joined using friction stir welding, simplifying the overall manufacturing process while maintaining weight reduction benefits.
Solution Approach 2:
The peripheral stiffening function is merged into the angular sector structures themselves rather than requiring a separate peripheral stiffener component. Each sector incorporates its own reinforcement features, eliminating the need for additional molding operations or assembly steps to attach peripheral stiffeners, thereby reducing mold complexity while maintaining structural performance.
6Ease of operation
If cold bonding of peripheral stiffening ring is used, then assembly is simplified, but temperature range compatibility is limited
Solution Approach 1:
The adhesive bonding process is replaced with friction stir welding, a solid-state welding process that joins sectors through mechanical interlocking and metallurgical bonding without requiring organic adhesives. This substitution eliminates the temperature limitations of cold bonding while maintaining assembly simplicity, enabling the reflector to operate across the required space environment temperature range (-200°C to +200°C).
Solution Approach 2:
The joining process transitions from chemical bonding (adhesive cold bonding) to mechanical/thermal bonding (friction stir welding). This parameter change in the joining mechanism removes the temperature constraints associated with adhesive materials, allowing the reflector to maintain structural integrity across the full operating temperature range required for space applications.
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
This design reduces labor time and weight, achieves the necessary resonance frequency, and maintains thermal stability across a wide temperature range, making it suitable for high-frequency applications in space environments while being more cost-effective than existing methods.
Implementation Method 1
at least one layer of fiber composite material comprises angular sectors arranged around a center, each of the angular sectors is defined by a first angle at the center, and is oriented along a median radial direction of the angle at the center, each of the angular sectors comprises the fiber composite material comprising first fibers oriented in a first direction and second fibers oriented in a second direction different from the first direction
Implementation Method 2
Applications in Q/V frequency bands require reaching an RMS of the order of 20 microns, displaying high stability of the reflective profile over a wide temperature range, ranging from -200°C to +200C. This imposes the use of materials with a low thermo-elastic coefficient of expansion.
Data Source
Figure 1a~1b
Figure 2~3
Figure 4
AI summary
The reflector has a reflective face for focusing electromagnetic radiation. A superposition of layers (C1-C6) comprises a fiber composite material. Each layer comprises angular sectors arranged around a center. Each sector is defined by a central angle and oriented in a radial direction that is a median of the central angle. The sector comprises the material comprising a set of fibers oriented in direction and another direction that is different from the former direction. The former direction forms an angle with the radial direction of the sector. The angular sectors comprise three concentric areas including a central area, a peripheral area and an intermediate area situated between the central area and the peripheral area, where the intermediate area forms a rim.