A review on measurements techniques in OATS and GTEM cell

The Open Area Test Site (OATS) method is the reference for measuring radiated RF-disturbances, according to the valid standards, even though there are numerous shortcomings inherent in this method. In practice, alternative methods in other measurement environments, such as the semi-anechoic chamber with conducting ground plane, free-space and GTEM-cell, have been applied with success. These procedures are applicable always when their measuring results correspond with the OATS measuring results. A great variety of reference measurement series are known from publications with which the correspondence of measuring results could be proved partially for certain equipment under test (EUT). In the paper, limits and possibilities of applying GTEM-cells are discussed in comparison with other methods. The data was gathered by using artificial EUTs for the entire frequency range. Contents and results of reference measurements are presented and discussed. The methods involved are scrutinised with their errors and uncertainty.