Multi-Layer Electromagnetic Absorber with Graded Refractive Index
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Solution Overview
Problem
Conventional electromagnetic absorbers fail to exhibit both low reflectance and low transmission coefficients at desired frequencies, limiting their effectiveness in applications such as electromagnetic shielding and antenna performance.
Innovation Solution
A multi-layer electromagnetic absorber comprising two or more layers with different indices of refraction, where the real part of the index increases from the proximal to the distal layer, and radiation-absorbing additives are distributed within the layers to enhance absorption and minimize transmission, achieving a reflectance and transmission coefficient of less than 0.3 across a frequency range of 1 GHz to 110 GHz.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electromagnetic absorbers are used, then they provide some level of absorption, but they cannot simultaneously achieve both low reflectance and low transmission coefficients
Solution Approach 1:
The absorber is divided into multiple layers (first layer, second layer, third layer) with progressively increasing real parts of their indices of refraction. This segmentation allows each layer to perform a specific function in the absorption process, collectively achieving both low reflectance and low transmission coefficients that cannot be achieved by a single-layer conventional absorber.
Solution Approach 2:
Each layer is assigned a specific local property (index of refraction value) that differs from the others. The first layer has a lower real part of the index of refraction, the second layer has an intermediate value, and the third layer has the highest value. This local quality differentiation enables progressive absorption and minimizes both reflection and transmission at different interfaces.
2Object-affected harmful factors
If a single-layer absorber is used, then the structure is simple, but it cannot achieve both low reflectance and low transmission coefficients simultaneously
Solution Approach 1:
The absorber is divided into multiple layers (first layer, second layer, third layer) with progressively increasing real parts of their indices of refraction. This segmentation allows each layer to perform a specific function in the absorption process, collectively achieving both low reflectance and low transmission coefficients that cannot be achieved by a single-layer conventional absorber.
Solution Approach 2:
The absorber uses a composite structure with three different layers, each having distinct electromagnetic properties (different real parts of indices of refraction). This composite material approach enables the system to achieve superior performance in minimizing both reflectance and transmission coefficients compared to any single homogeneous material.
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 multi-layer absorber effectively minimizes electromagnetic radiation reflection and transmission, ensuring high absorption across the specified frequency range, making it suitable for applications requiring both low reflectance and low transmission coefficients.
Implementation Method 1
two or more layers with different indices of refraction, where the real part of the index increases from the proximal to the distal layer
Implementation Method 2
radiation-absorbing additives are distributed within the layers to enhance absorption and minimize transmission
Data Source
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AI summary
In one aspect, a multi-layer absorber is disclosed, which comprises a proximal layer having a radiation-receiving surface adapted for receiving electromagnetic radiation, and a distal layer disposed adjacent the proximal layer to receive at least a portion of the received radiation, if any, transmitted through said proximal layer, wherein said proximal layer exhibits an index of refraction having a real part that is less than the real part of an index of refraction of the said distal layer for at least one frequency of the electromagnetic radiation in a range of about 1 GHz to about 110 GHz.