A novel automatic digital quasi-peak detector for a time domain measurement system

An advanced ultra-fast broadband time domain EMI (TDEMI) measurement system is presented. Measurements were performed in the 30-1000 MHz range. Using digital signal processing for spectral estimation and detection, the measurement time is reduced by a factor of 10 in comparison to a conventional EMI receiver. A novel recording routine for TDEMI measurement and digital signal processing for proper quasi-peak detection is described. Different amplitude resolutions are selected during the recording to enhance the dynamic range by about 50 dB. Measurement results are compared with the results obtained with a conventional EMI receiver.