Carbon Fiber Shielding Molding for 59-100 GHz Wave Absorption
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Solution Overview
Problem
Existing millimeter wave radar devices face reduced detection accuracy due to radio wave interference, and current electromagnetic wave shielding solutions do not adequately address the issue of shielding and absorbing electromagnetic waves in the specific frequency range of 59 GHz to 100 GHz.
Innovation Solution
A thermoplastic resin composition containing carbon fibers with specific weighted average fiber lengths and content ratios, used to create an electromagnetic wave shielding and absorbing molded article with enhanced shielding properties and absorbency, achieving a shielding property of 10 dB or greater and absorbency of 5% or greater in the frequency range of 59 GHz to 100 GHz.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional shielding members are used to block radio waves, then shielding effect is improved, but detection accuracy deteriorates due to reflected waves
Solution Approach 1:
The patent converts the harmful reflected radio waves into beneficial absorbed energy by using a shielding member with specific electromagnetic wave absorbing properties. The shielding member absorbs reflected waves from the road surface and other objects, preventing them from returning to the antenna and causing interference, thereby improving detection accuracy while maintaining shielding effect
Solution Approach 2:
The patent changes the electromagnetic parameters of the shielding member by incorporating carbon fibers with specific characteristics (fiber length of 0.5 to 15 mm, aspect ratio of 5 to 50, content of 1 to 50 mass%) into the resin composition. These parameter changes enable the shielding member to achieve both shielding and absorbing functions, resolving the contradiction between shielding effect and detection accuracy
2Object-affected harmful factors
If carbon fiber content is increased to improve shielding property, then shielding effect is improved, but material cost and weight increase
Solution Approach 1:
The patent optimizes the carbon fiber parameters (fiber length, aspect ratio, and content) to achieve the minimum effective concentration. By specifying carbon fibers with length of 0.5 to 15 mm and aspect ratio of 5 to 50, the patent achieves effective shielding and absorbing properties with carbon fiber content of only 1 to 50 mass%, reducing material usage compared to conventional solutions
Solution Approach 2:
The patent creates a composite material system combining resin base material with specifically selected carbon fibers. This composite structure achieves synergistic effects where the carbon fibers provide both shielding and absorbing functions while the resin matrix provides structural support, allowing effective electromagnetic wave protection with optimized material composition
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 effectively increases both shielding and absorbency performance for electromagnetic waves, improving the detection accuracy of millimeter wave radar devices by effectively shielding and absorbing electromagnetic waves within the specified frequency range.
Implementation Method 1
an electromagnetic wave shielding and absorbing molded article including a thermoplastic resin composition that contains a thermoplastic resin and carbon fibers
Implementation Method 2
the electromagnetic wave shielding and absorbing molded article has a shielding property of 10 dB or greater and an absorbency of 5% or greater for electromagnetic waves having any frequency in a frequency domain from 59 GHz to 100 GHz
Implementation Method 3
a shielding member that shields radio waves between the antenna and the control circuit
Data Source
AI summary
Provided is an electromagnetic wave shielding and absorbing molded article which has an excellent shielding property and absorbency of electromagnetic waves of specific frequencies. The electromagnetic wave shielding and absorbing molded article includes a thermoplastic resin composition containing a thermoplastic resin and carbon fibers. The carbon fibers have a weighted average fiber length in the molded article in a range from 0.05 to 8.0 mm, and the content ratio of the carbon fibers in the molded article is from 0.05 to 45 mass %. The electromagnetic wave shielding and absorbing molded article has a thickness from 0.01 mm to 5 mm, a shielding property of 10 dB or greater and an absorbency of 5% or greater for electromagnetic waves having any frequency in a frequency domain from 59 GHz to 100 GHz.