Signal processing strategies with the TDEMI measurement system

A low-cost electromagnetic compatibility precompliance test-set is essential to reduce the development costs of any electrical device. In this paper we discuss the advantages of broadband time-domain preliminary compliance measurement techniques applied to all types of electromagnetic interferences. The digital signal processing of electromagnetic interference measurements allows emulating in real-time the various modes of conventional analogous equipment, e.g., peak, average, root mean square, and quasi-peak detector mode. Since time-domain techniques allow processing the whole amplitude spectrum in parallel, the measurement time may be reduced by at least one order of magnitude. Compliance measurement results for conducted and radiated emissions obtained with the time-domain electromagnetic interference (TDEMI) system are shown. The TDEMI system has a real-time bandwidth of 1.5 GHz. Measurement techniques for nonstationary signals and single events are discussed.