To improve the reflection performance of absorbers used in anechoic chambers, several different electromagnetic wave absorber geometries similar to conventional wedge absorber structures are proposed in this study. Design basics are examined by using the reflection and absorption of electromagnetic waves. The return loss characteristics of each absorber structure which is illuminated by a TE polarized plane wave have been obtained using well-known simulation software for several incidence angles. Comparisons of the simulation results of the conventional wedge and proposed absorbers are presented. The results show that new absorber shapes provide better absorption characteristics than a conventional wedge across almost all frequency ranges, and especially for normal and near normal incidence cases.
2. Nornikman, H., F. B. A. Malek, P. J. Soh, A. A. H. Azremi, F. H. Wee, and A. Hasnain, "Parametric study of pyramidal microwave absorber using rice husk," Progress In Electromagnetics Research, Vol. 104, 145-166, 2010.
3. Neher, L. K., "Nonreflecting background for testing microwave equipment,", U.S. Patent, 2 656 535, Oct. 20, 1953.
4. Emerson, W. H., "Electromagnetic wave absorbers and anechoic chambers through the years," IEEE Trans. Antennas Propagat., Vol. 21, 484-490, 1973.
5. Demotte, F. E., "Electromagnetic radiation absorbing means,", U.S. Patent Application, 769 710, Aug. 20, 1947.
6. Tanner, H. A., "Fibrous microwave absorber,", U.S. Patent, 2 977 591, 1952.
7. Tong, X. C., "Advanced Materials and Design for Electromagnetic Interference Shielding," Taylor & Francis Group, 237-255, 2009.
8. Chung, B. and H. Chuah, "Modeling of RF absorber for application in the design of anechoic chamber," Progress In Electromagnetics Research, Vol. 43, 273-285, 2003.
9. Ishimaru, A., Electromagnetic Wave Propagation, Radiation, and Scattering, 31-75, Prentice Hall, 1991.
10. Bell, R. J., K. R. Armstrong, C. S. Nichols, and R. W. Bradley, "Generalized laws of refraction and reflection," J. Opt. Soc. Am., Vol. 59, 187-189, 1969.
11. Cheng, D. K., Field and Wave Electromagnetics, 2nd Ed., 411-417, Addison Wesley, 1989.
12. Kuester, E. and C. Holloway, "A low-frequency model for wedge or pyramid absorber arrays --- I: Theory," IEEE Transactions on Electromagnetic Compatibility, Vol. 36, No. 4, 300-306, 1994.
13. Rayleigh, L., "On the dynamical theory of gratings," Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character, Vol. 79, No. 532, 399-416, Aug. 1907.
14. Rayleigh, L., The Theory of Sound, Dover, New York, 1945, Originally Published in 1877.
15. Pinel, N., J. Saillard, and C. Bourlier, "Extension of the roughness criterion of a one-step surface to a one-step layer," Journal of Electromagnetic Waves and Applications, Vol. 24, No. 8-9, 1195-1205, 2010.
16. Pinel, N., C. Bourlier, and J. Saillard, "Degree of roughness of rough layers: Extensions of the Rayleigh roughness criterion and some applications," Progress In Electromagnetics Research B, Vol. 19, 41-63, 2010.
17. Holloway, C. L., R. R. DeLyser, R. F. German, P. McKenna, and M. Kanda, " Comparison of electromagnetic absorber used in anechoic and semi-anechoic chambers for emissions and immunity testing of digital devices," IEEE Trans. Electromagnetic Compatibility, Vol. 39, 33-47, 1997.