Issue
EPL
Volume 77, Number 6, March 2007
Article Number 68006
Number of page(s) 4
Section Interdisciplinary Physics and Related Areas of Science and Technology
DOI http://dx.doi.org/10.1209/0295-5075/77/68006
Published online 07 March 2007
EPL, 77 (2007) 68006
DOI: 10.1209/0295-5075/77/68006

Design, fabrication and characteristic of two-layer microwave absorbers composed of magnetic micropowder-rubber composites in X-band frequency range

Yanfei He, Rongzhou Gong, Xiangcheng Li, Xian Wang and Qifa Hu

Department of Electronic Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, PRC

husthyf1203@yahoo.com.cn

received 8 December 2006; accepted in final form 30 January 2007; published March 2007
published online 7 March 2007

Abstract
Both experimentally and theoretically, a two-layer microwave absorber exhibits the possibility of meeting the demand for effective radar absorbing materials. The design methodology is based on the modulus of permittivity (permeability) which obeys a logarithmic law of mixtures, and the loss tangent is related through a linear law of mixtures. A linear regression analysis performed on the data points provides constants that can be used to predict the effective parameters at different frequencies, and a program is presented that computes the optimum amount of magnetic micropowder and the required thickness for each layer. A two-step sulfur treatment is then applied to preparation of the two-layer absorber, vulcanized firstly by heating at $165\,^{\circ }{\rm C}$ for 15 min and then at $150\,^{\circ }{\rm C}$ for 4 h. Finally, tensile strength is experimentally investigated as well as power reflection coefficient. Test results indicate the two-layer absorber has excellent mechanical and microwave attenuation properties for X-band frequency.

PACS
81.05.-t - Specific materials: fabrication, treatment, testing, and analysis.
75.50.-y - Studies of specific magnetic materials .
07.05.Tp - Computer modeling and simulation .

© Europhysics Letters Association 2007