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Title: A new measure for evaluating shielding performance of an equipment enclosure at frequencies above 1 GHz
Author: Cui, Yong
ISNI:       0000 0004 2708 7281
Awarding Body: University of York
Current Institution: University of York
Date of Award: 2007
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The measure of shielding effectiveness (SE) and the related measurement techniques proposed by the current IEEE Standard 299 are only applicable for large screened enclosures having dimensions more than 2 m. To propose reasonable measures to assess the shielding performance of an equipment enclosure, together with the relevant measurement techniques, is the subject of this thesis. This work is informing the new developments in IEEE Standard 299. To coincide with the practical applications of most equipment enclosures, two measurement approaches distinguished by the location of the radiation source are considered in this thesis, and the measurement is performed in the radiating nearfield with test frequencies above 1 GHz. The contents inside the enclosure are stressed and involved in all the measurements. In the first measurement approach, to measure the enclosure’s ability to prevent the electromagnetic waves of internal contents from radiating outside to cause interference with nearby equipments, an emission source is -placed inside the enclosure and a receive antenna is placed outsic’j. A new measure shielding of radiating power (SRP) is proposed here, which consists of two parameters: the average shielding of radiating power (ASRP) and the enhancement factor E.F.g5lh. Two measurement environments: anechoic chamber and reverberation chamber are considered and compared. To avoid the huge measurement work in an anechoic chamber, the reverberation chamber is proposed as an ideal test environment to determine the ASRP, and the estimation of the enhancement factor E.F.gnh can be given directly based on statistic analyses on both measurement and simulation results. In the second measurement approach, to measure the enclosure’s ability to shield the internal contents against external interference, the enclosure is placed in a small reverberation chamber and illuminated by external electromagnetic field. Another new measure shielding of absorption cross section (SACS) is proposed here. However, measurement results indicate this measure has distinct advantages and disadvantages, so it is suggested prudently. Finally the first measure is proposed and reverberation chamber is suggested as the ideal test environment.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available