Problems with radiated-emission testing at 3 m distance according to CISPR 11 and CISPR 22

The standards CISPR 11 and CISPR 22 specify different extrapolation factors for radiated-emission test data measured at 3-m distance. The authors have experimentally determined extrapolation factors for a personal computer that radiated the signal from a comb generator via its wiring harness and for a battery-powered reference radiator. Results show that factors can vary between -18 dB and -1 dB. It is concluded that, based on the present specifications, compliance tests at 3-m distance should not be allowed.<<ETX>>