Sensitivity of Frequency-Swept Shielding Effectiveness Measurements to Reflecting Surfaces and EMI Noise in the Test Area

This paper reports and compares empirical outcomes of frequency-swept Shielding Effectiveness (SE) measurements for several types of metallic enclosures, performed under two extreme conditions. In one case, the test is done in an area with numerous metallic surfaces and/or objects, and in the other case reflecting surfaces and/or objects are practically nonexistent. It is demonstrated that the data from the first case does not exhibit a significant sensitivity to the existence of reflecting surfaces and/or objects in the test area. These outcomes suggest that the frequency-swept method offers the designer a quick and inexpensive method of measuring the effective SE as a function of excitation frequency.