The effect of EUT position on Gigahertz Transverse Electromagnetic (GTEM) cell correlation algorithms

Previous work has shown that the transverse and longitudinal position of an emissions source within a gigahertz transverse electromagnetic (GTEM) cell will affect the measured voltages at the apex of the cell. Since the emissions source(s) on an EUT may not always correspond with the measurement position origin, this may have an effect on the correlation algorithm used to simulate radiated emissions at an open-air test site (OATS). This paper analyzes why such measurement differences occur and shows the effect shifts in the emissions source location relative to the measurement position origin has on two correlation algorithms. Specifically, it examines the 3-position total radiated power algorithm and the 9-position multipole algorithm.