Reproducibility and uncertainty in radiated emission measurements at open area test sites and in semianechoic chambers using a spherical dipole radiator

Radiated emission (RE) measurements have been made in a 3 m semianechoic chambers (SACs) and at a 10 m open area test sites (OATSs) using a spherical dipole radiator (SDR) as a reference emitter. To compare the electric field strengths of the SACs with those of the OATSs, the analytical extrapolation factor for the SDR is employed. For the experiments, 23 discrete frequencies are chosen in the frequency range of 30 to 1000 MHz. The resultant reproducibility (2(sigma)) was 7.3 and 6.0 dB for the SAC and the OATS measurements respectively. To account for the possible contributions to the overall uncertainty, the expanded uncertainty (k=2) is evaluated and found to be 5.1 and 5.3 dB for the SAC and OATS measurements, respectively.