A time-domain diagnostic method for emission measurements in TEM cells

Emission testing techniques using TEM cells, are currently based on power measurements at their port(s) in the frequency-domain . Spectrum measurements do not give directly phase information and therefore only offer partial information on the electromagnetic emission of an equipment under test (EUT such as the total radiated power. This drawback often leads to difficulties in interpreting the emission results in order to determine precisely the origins of radiation within the EUT and to improve its design. This paper presents a new diagnostic method based on time-domain emission measurements using TEM cells in order to determine the origins of radiation within an EUT. Unlike spectrum measurements, time-domain measurements can offer full information on radiation, and by correlation with the known currents in the EUT, can help pin-pointing the contributors within the EUT responsible of the highest emission levels.