Design of Composite Electromagnetic Wave Absorber Made of Fine Aluminum Particles Dispersed in Polystyrene Resin by Controlling Permeability

PIERS Online ◽  
2009 ◽  
Vol 5 (7) ◽  
pp. 663-670 ◽  
Author(s):  
Kenji Sakai ◽  
Yoichi Wada ◽  
Yuuki Sato ◽  
Shinzo Yoshikado
Keyword(s):  
Electromagnetic Wave ◽  
Aluminum Particles ◽  
Polystyrene Resin

Composite Electromagnetic Wave Absorber Made of Both Sendust and Aluminum Particles Dispersed in Polystyrene Resin

2010 ◽  
Vol 445 ◽  
pp. 197-200
Author(s):  
Kenji Sakai ◽  
Yang Guan ◽  
Yuuki Sato ◽  
Shinzo Yoshikado
Keyword(s):  
Particle Size ◽  
Electromagnetic Wave ◽  
Return Loss ◽  
Complex Permeability ◽  
Frequency Range ◽  
Aluminum Particles ◽  
Absorption Properties ◽  
Mixture Ratio ◽  
Polystyrene Resin ◽  
Frequency Dependences

To design an electromagnetic wave absorber with good absorption properties at frequencies above 1 GHz, the frequency dependences of the relative complex permeability μr*, the relative complex permittivity εr*, and return loss were investigated for the composite made of both sendust (an alloy of Al 5%, Si 10%, and Fe 85%) and aluminum particles dispersed in polystyrene resin. It was found that the frequency dependence of μr* for this composite can be changed by adjusting the particle size of aluminum and the volume mixture ratio of sendust and aluminum. Therefore, a flexible design of an absorber with good absorption characteristics was proposed based on the ability to control μr*. The composite made of both sendust and aluminum was found to exhibit a return loss of less than −20 dB in the frequency range of not only several GHz but also around 20 GHz if appropriate volume mixture ratio and particle size were selected.

Evaluation of Composite Electromagnetic Wave Absorber made of Polystyrene Resin and Permalloy or Sendust

2007 ◽  
Vol 350 ◽  
pp. 239-242 ◽  
Author(s):  
Kenji Sakai ◽  
Shinzo Yoshikado
Keyword(s):  
Electromagnetic Wave ◽  
Magnetic Materials ◽  
Electromagnetic Waves ◽  
Return Loss ◽  
Soft Magnetic Materials ◽  
Complex Permeability ◽  
Soft Magnetic ◽  
Mixture Ratio ◽  
Polystyrene Resin ◽  
Frequency Dependences

The frequency dependences of the complex permeability μ r*, complex permittivity ε r*, and return loss were investigated for composite electromagnetic wave absorbers made of soft magnetic materials (permalloy or sendust) and polystyrene resin. For permalloy, two types of particle shape were used: grain-type or flake-type. The volume mixture ratio of magnetic materials was varied in the range from 40 % to 70 %. The values of the real part μ ’ and imaginary part μ ” of μ r * increased with increasing mixture ratio of magnetic materials. The frequency dependence of μ r * for flake-type permalloy composite was similar to that for sendust composite. All absorbers showed the absorption of electromagnetic waves in the frequency range above 1 GHz.

Effect of Sendust Particle Size on Absorption Characteristics of Composite Electromagnetic Wave Absorber

2009 ◽  
Vol 421-422 ◽  
pp. 451-454
Author(s):  
Kenji Sakai ◽  
Yoichi Wada ◽  
Yuuki Sato ◽  
Shinzo Yoshikado
Keyword(s):  
Particle Size ◽  
Electromagnetic Wave ◽  
Return Loss ◽  
Single Layer ◽  
Complex Permeability ◽  
Wave Power ◽  
Flexible Design ◽  
Frequency Range ◽  
Polystyrene Resin ◽  
Absorption Characteristics

The effects of the particle size of sendust, which is an alloy of Al 5%, Si 10%, and Fe 85%, on the absorption characteristics of composite electromagnetic wave absorbers made of polystyrene resin and sendust were investigated in the frequency range from 1 to 40 GHz. The size of sendust particles was varied between approximately 5 and 20 m. A metal-backed single-layer absorber made of 20 m sendust particles absorbed more than 99% of electromagnetic wave power at frequencies above 20 GHz. Meanwhile, a composite made of 5 m particles exhibited a return loss of less than −20 dB in the frequency range of not only several GHz but also above 30 GHz. In addition, the relative complex permeability r* was shown to be controlled by adjusting the particle size of sendust, and an electromagnetic wave absorber with a flexible design was proposed.

Absorption Characteristics of Composite Electromagnetic Wave Absorber Made of Sendust Particles Dispersed in Polystyrene Resin

2013 ◽  
Vol 566 ◽  
pp. 215-218
Author(s):  
Yuki Hongo ◽  
Kenji Sakai ◽  
Yuuki Sato ◽  
Shinzo Yoshikado
Keyword(s):  
Electromagnetic Wave ◽  
Low Cost ◽  
Volume Ratio ◽  
Average Particle ◽  
Particle Sizes ◽  
Frequency Bandwidth ◽  
Rare Metals ◽  
Absorption Frequency ◽  
Polystyrene Resin ◽  
Absorption Characteristics

A low-cost composite electromagnetic wave absorber made of sendust dispersed in resin was developed that does not contain any rare metals. In this study, spherical sendust particles with average particle sizes of approximately 5 and 20 μm were dispersed in polystyrene resin at volume ratios in the range 2040 vol% to broaden the absorption frequency bandwidth at frequencies above 10 GHz. The optimal volume ratios of sendust with average particle sizes of approximately 5 and 20 μm were found to be approximately 30 and 35 vol%, respectively. Electromagnetic wave absorbers can be flexibly designed by controlling the volume ratio of spherical sendust particles in resin.

Dielectric and Magnetic Properties of Cermets with Iron-Aluminum Dual Metallic Particles

2017 ◽  
Vol 898 ◽  
pp. 1655-1660
Author(s):  
Kai Sun ◽  
Zhong Yang Wang ◽  
Pei Tao Xie ◽  
Run Hua Fan
Keyword(s):  
Magnetic Properties ◽  
Electromagnetic Wave ◽  
Dielectric Properties ◽  
Wave Attenuation ◽  
Primary Role ◽  
Alumina Matrix ◽  
Aluminum Particles ◽  
Metallic Particles ◽  
Iron Aluminum ◽  
Permittivity And Permeability

The dual metallic components, i.e., iron-aluminum particles were distributed in alumina matrix to fabricate lossy cermets. The electromagnetic parameters including ac conductivity, the complex permittivity and permeability were investigated. With the increase of filler fractions, the conductive carriers instead of the dipoles played a primary role in conductive and dielectric properties. Hopefully, the cermets composites could be promising candidates for electromagnetic wave attenuation and shielding.

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