Hexagonal Ferrite Magnetic Powder for Radar Wave Attenuation
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Solution Overview
Problem
Current radio wave absorbers used in radar systems have limitations in achieving high transmission attenuation characteristics, which affect the recognition accuracy and reliability of object detection, particularly in automotive radar applications.
Innovation Solution
A magnetic powder composed of hexagonal ferrite with a specific composition and surface region structure, represented by Formula AFe(12-x)AlxO19, where A represents Sr, Ba, or Ca, and x ranges from 0.10 to 5.00, is developed. This powder is used to enhance the transmission attenuation characteristics of radio wave absorbers by optimizing the content and distribution of A and Al atoms on the particle surface, as determined by SEM and EDS analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional magnetic powders are used in radio wave absorbers, then the basic radio wave absorption function is achieved, but the transmission attenuation characteristics are insufficient
Solution Approach 1:
The patent changes the chemical composition parameters of the magnetic powder by controlling the substitution amount of divalent metal atoms for trivalent metal atoms in the ferrite structure, and by controlling the particle size distribution parameters. These parameter changes optimize the transmission attenuation characteristics while maintaining radio wave absorption functionality.
Solution Approach 2:
The patent uses composite magnetic powder materials with specific compositional ratios of different metal elements (Fe, Al, and divalent metal atoms such as Mn, Zn, Co, Ni, Cu, or their combinations). This composite approach creates synergistic effects that improve transmission attenuation while preserving the essential radio wave absorption properties.
2Loss of energy
If the radio wave absorber is designed to improve transmission attenuation, then the energy absorption capability increases, but the system complexity increases
Solution Approach 1:
The patent achieves improved transmission attenuation by optimizing compositional parameters (metal atom ratios, substitution amounts) and physical parameters (particle size distribution) of the magnetic powder, rather than by complicating the absorber structure. This allows high performance with relatively simple manufacturing processes.
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 magnetic powder significantly improves the transmission attenuation characteristics of radio wave absorbers, leading to enhanced recognition accuracy and reliability in radar systems, particularly in automotive applications, by effectively absorbing radio waves across a wide frequency range.
Implementation Method 1
a radio wave absorber containing the magnetic powder for a radio wave absorber
Implementation Method 2
a magnetic powder for a radio wave absorber... having a composition represented by Formula 1: AFe(12-x)AlxO19
Data Source
AI summary
The magnetic powder for a radio wave absorber is a powder of a hexagonal ferrite having a composition represented by Formula 1, a region B is present on the particle surface of the powder, and Expression 2: 0.3≤content of A atom in region B/content of Al atom in region B≤23.0 and Expression 3: 1.2≤total of content of A atom and content of Al atom in region B/total of content of A atom and content of Al atom in entire powder≤2.5 are satisfied. The region B is a region that is observed as a bright region having a long side diameter of 0.1 μm to 0.6 μm in an image subjected to binarization processing. A represents one or more kinds of atoms (A atom) selected from the group consisting of Sr, Ba, Ca, and Pb, and x satisfies 0.10≤x≤5.00.AFe(12-x)AlxO19 (Formula 1)