Maximum Emission from Electrically Large Sources in EMI Measurements - Comparing Measurements and Theoretical Estimates

Increasing frequencies in emission measurements also increase the influence of the measurement methods used for established test sites. This paper shows a comparison of the measured maximum electric field strength of an artificial equipment under test (EUT) in a fully anechoic room. The influence of the spatial scanning on the measured maximum electric field strength is presented. The estimate of the directivity based on the electrical size of the EUT will be shown. This is important to evaluate the validity of measurements and to understand the correlation and reasons for differences between measurements in established and alternative test sites. In order to reduce time-consuming measurements and increase test efficiency, statistical methods should be taken into account to estimate the maximum emission based on a technically and economically reasonable sampling of the EUT’s emission.