Asymmetric versus symmetric TEM cells for EMI measurements
Abstract
The present analysis deals with the option of designing a transverse electromagnetic (TEM) transmission cell with an off-set septum as a multipurpose chamber for performing EMI/EMC measurements. Since only one half-space is used for most of the measurements made with a symmetric cell, the idea is to reduce the size (and hence the cost) of a cell by making it asymmetric. The analysis shows that a versatile asymmetric cell for multipurpose use can be achieved at the expense of degraded high frequency (multimode) characteristics. An increase in test volume versus bandwidth is possible with an asymmetric cell, but with a sacrifice of about 1 dB in uncertainty in determining the test field. Also, a substantial increase in uncertainty is expected (as compared to a symmetric cell) when using the asymmetric cell at multimode frequencies.
- Publication:
-
International Symposium on Electromagnetic Compatibility
- Pub Date:
- 1978
- Bibcode:
- 1978emc..symp..204C
- Keywords:
-
- Electromagnetic Interference;
- Electromagnetic Measurement;
- Electronic Equipment Tests;
- Electronic Transducers;
- Transverse Waves;
- Coaxial Cables;
- Electric Fields;
- Symmetry;
- Communications and Radar