Efficient Time-Domain Multi-Channel Measurements using a Multi-Axis Antenna for Frequency Range below 30 MHz

Radiated electromagnetic interference measurements were traditionally done in the frequency domain. A super-heterodyne EMI test receiver is then analyzing each frequency individually during a sweep across the spectrum. Despite the high accuracy, the time needed for the measurements sometimes reaches several days due to the small bandwidth and thus long dwell time, especially in the low-frequency range below 30 MHz. Modern time-domain EMI analyzers already created maj or reductions in measurement time. Some standards require measuring with several magnetic loop antenna orientations with respect to the equipment under test. Instead of the expensive single-channel time-domain analyzers, cost-efficient multichannel digitizers are proposed to perform measurements using several magnetic loop antenna positions and polarizations simultaneously.