Conducted EMI analysis. A case study

Commercial international regulations/standards call for specific impulsive bandwidths to measure types of emission in the frequency range of interest. Such bandwidths are specified in International Special Committee on Radio Interference (CISPR) specification no. 16-1. When emissions exceed average regulatory limits, but remain below quasi-peak limits, average analysis is carried out. Averaging of EMI in a spectrum analyser (SA) is accomplished with a video filter. Selection of improper bandwidth of the video filter results in numerous errors. Subject analysis is required to be carried out in the linear amplitude mode of a SA. However if the logarithmic amplitude mode is selected, it may affect average analysis. The present paper intends to find the parameters which can influence conducted EMI average analysis.