Real performance of semi-anechoic chambers depending on absorber technology

Standardized measurement procedures for field homogeneity restrict themselves to antennas which have simple and stable radiation characteristics. However, the complicated radiation patterns of real devices might react with a greater sensitivity to their surroundings. In such a case larger errors in the field strength determination arise than are suggested by standardized compliance tests of alternate test sites. The demonstration of such discrepancies sheds new light on the suitability of all kinds of alternate test sites for EMC-testing as well as the suitability of different absorber technologies for anechoic chambers.