Fractal Plasmonic Surface for Wideband Electromagnetic Shielding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current technologies for electromagnetic shielding and cloaking are limited in their ability to effectively reduce radar cross-section across a wide range of electromagnetic radiation frequencies and provide invisibility, as they often rely on narrow band responses and are not scalable for various wavelengths.
Innovation Solution
The use of close-packed fractal plasmonic surfaces with resonators of fractal shapes, which replicate current between adjacent cells, allowing for wide bandwidth transmission and cloaking effects by diffusing or diverting electromagnetic radiation, and can be designed for specific frequency ranges including visible light, infrared, and microwave frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional electromagnetic shielding materials are used, then radar cross section reduction is achieved, but the shielding is limited to small ranges of electromagnetic radiation frequencies
Solution Approach 1:
The shielding surface is divided into multiple fractal cells with self-similar patterns at different scales. Each cell independently interacts with electromagnetic waves, and the collective arrangement provides broad frequency coverage while maintaining shielding effectiveness across the spectrum.
Solution Approach 2:
The fractal geometry parameters (such as iteration level, scaling factor, and cell size) are optimized to achieve resonance at multiple frequency bands. By adjusting these parameters, the shielding structure can be tuned to cover specific frequency ranges while maintaining robust performance.
2Adaptability or versatility
If narrow band metamaterials are used to achieve negative index of refraction, then cloaking effect is produced, but the response bandwidth is typically less than 5%
Solution Approach 1:
The fractal plasmonic surface serves multiple functions: it provides electromagnetic shielding, enables cloaking effects, and achieves broad bandwidth transmission. The self-similar fractal pattern inherently supports multiple frequency interactions, making the structure universally applicable across different frequency ranges.
Solution Approach 2:
The fractal structure introduces self-similarity across multiple spatial scales, effectively adding a dimensional aspect to the metamaterial design. This multi-scale geometry enables the structure to interact with electromagnetic waves of different wavelengths simultaneously, achieving broad bandwidth without increasing structural complexity.
3Adaptability or versatility
If close-packed fractal cells are used to replicate current, then wide bandwidth transmission is achieved, but the manufacturing precision requirements increase
Solution Approach 1:
The fractal cells are designed with self-similar patterns that maintain their electromagnetic properties even with local variations in spacing or alignment. This local quality robustness allows manufacturing tolerances to be relaxed while still achieving the desired wide bandwidth transmission and current replication effects.
Solution Approach 2:
The close-packed arrangement of identical fractal cells creates a periodic structure that replicates current patterns across the surface. This copying effect enhances bandwidth transmission by distributing the electromagnetic interaction across multiple identical units, reducing the impact of individual cell variations.
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 approach enables effective electromagnetic shielding and cloaking across various frequency ranges, providing invisibility and power control by diffusing electromagnetic radiation, and is robust against damage to individual cells due to multiple transfer paths.
Implementation Method 1
fractal cells placed sufficiently close together to one another (e.g., less than 1/20 wavelength) to produce substantial replication of current present in one fractal cell in an adjacent fractal cell
Implementation Method 2
Such a fractal plasmonic surface (FPS) may be used to transfer radiation, e.g., via evanescent wave transfer
Implementation Method 3
close packed arrangements of resonators having fractal shapes, i.e., 'fractal cells'
Data Source
AI summary
Systems according to the present disclosure provide one or more surfaces that function as power transferring surfaces for which at least a portion of the surface includes or is composed of “fractal cells” placed sufficiently closed close together to one another so that a surface (plasmonic) wave causes near replication of current present in one fractal cell in an adjacent fractal cell. A fractal of such a fractal cell can be of any suitable fractal shape and may have two or more iterations. The fractal cells may lie on a flat or curved sheet or layer and be composed in layers for wide bandwidth or multibandwidth transmission.