Shielding Effectiveness estimation of physically small electrically large enclosures through dimensional scaling

Current Shielding Effectiveness (SE) measurements using the nested chamber method require an electrically large enclosure to ensure predicable field statistics. The main limitation on the enclosure-under-test for this type of measurement is its lowest useable frequency, especially as real world equipment enclosures are reducing in physical size. In this paper, the idea of electrical scalability is investigated, i.e. using a larger enclosure to mimic a smaller one. Results from three electrically scaled aperture dominated enclosures are presented and the relationship between them discussed. The use of Q-factor suggested in earlier work is applied to the three enclosures-under-test and the relationship is examined.

[1]  Raj Mittra,et al.  Electromagnetic Penetration Through Apertures in Conducting Surfaces , 1978, IEEE Transactions on Electromagnetic Compatibility.

[2]  David A. Hill,et al.  An improved model for antennas in reverberation chambers , 2010, 2010 IEEE International Symposium on Electromagnetic Compatibility.

[3]  A.C. Marvin,et al.  Use of Reverberation Chambers to Determine the Shielding Effectiveness of Physically Small, Electrically Large Enclosures and Cavities , 2008, IEEE Transactions on Electromagnetic Compatibility.

[4]  A.C. Marvin,et al.  A study of enclosure shielding effectiveness measurement using frequency stirring in a mode-stirred chamber , 2008, 2008 IEEE International Symposium on Electromagnetic Compatibility.

[5]  John Dawson,et al.  An experimental investigation of the use of Q-factor to determine the shielding effectiveness of electrically large equipment enclosures with apertures , 2011, 10th International Symposium on Electromagnetic Compatibility.

[6]  J. Clegg,et al.  Radio frequency electromagnetic fields in large conducting enclosures: effects of apertures and human bodies on propagation and field-statistics , 2006, IEEE Transactions on Electromagnetic Compatibility.