Shielding Effectiveness Analysis of a Spherical Shield Made of Medium Conductivity Material against Low-Frequency Electric Field

Abstract:

With quasi-static field approximation, an analytic formula is derived for shielding effectiveness analysis of a spherical shield made of medium conductivity material (10 S/m-1000 S/m) against low-frequency electric field. The effects of frequency, material conductivity, and shield dimensions on shielding effectiveness are investigated. It is shown that the shielding effectiveness decreases at first and then increases with the frequency increasing from DC to MHz if the thickness of the shield is large. However, the shielding effectiveness decreases versus the increase of frequency continuously if the thickness is small. The shielding effectiveness can be enhanced by increasing either the material conductivity or the shield thickness. This research is helpful for the evaluation of composite conductive material for electromagnetic shielding applications.

• Periodical: Applied Mechanics and Materials (Volume 734)
• Pages: 858-863
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.734.858
• Online since: February 2015
• Authors: Ming Yang Li*, Chong Qing Jiao, Jing Kai Nie
• Keywords: Conducting Material, Low-Frequency Electric Field, Shielding Effectiveness, Spherical Shield

References

[1] Z. A. Khan, C. F. Bunting, and M. D. Deshpande. , Shielding effectiveness of metallic closures at oblique and arbitrary polarizations, IEEE Trans. Electromagn. Compat., vol. 47, no. 1, p.112–122, Feb. (2005).

DOI: 10.1109/temc.2004.842117

[2] C. W. Harrison, JR., C. H. Papas, On the attenuation of transient fields by imperfectly conducting spherical shields, IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, vol. ap-13, NO. 6 (1965).

DOI: 10.1109/tap.1965.1138552

[3] Frederick M. Tesche, EMC analysis methods and computational models, A JOHN WILEY & SONS, INC., (1996).

[4] A. Goldman, Handbook of Modern Ferromagnetic Materials, Boston: Kluwer, (1999).

[5] P. S. Neelakanta, Handbook of Electromagnetic Materials: Monolithic and Composite Versions and their Applications, Boca Raton: CRC Press, (1995).

[6] Paulis, F.; Nisanci, M. H.; Orlandi, A.; Koledintseva, M. Y.; Drewniak, J. L.; Design of Homogeneous and Composite Materials From Shielding Effectiveness Specifications, Electromagnetic Compatibility, IEEE Transactions on Volume: 56 , Issue: 2 2014 , Page(s): 343 - 351.

DOI: 10.1109/temc.2013.2280463

[7] Julius Adams Stratton, Electromagnetic Theory, Wiley-IEEE Press, (2007).

[8] Salvatore celozzi, Rodolfo araneo, Giampiero lovat, Electromagnetic Shielding, A JOHN WILEY & SONS, INC., (2008).

[9] Shanjie Zhang, Vector analysis, cylindrical functions and spherical functions, Nanjing University Press, Nanjing , 2011, In Chinese.

[10] Guangzheng Ni, Electromagnetic Engineering, second edition, Higher Education Press, 2009, In Chinese.