Frequency spectrum analysis method for short-time and frequency conversion signals based on simulation EMI receiver

The traditional electromagnetic interference(EMI) measurement equipments, such as EMI receiver and spectrum analyzer, can´t measure the frequency spectrum of the short-time and frequency conversion signal precisely. This paper proposed a novel method,which is based on simulation EMI receiver, to solve this problem. Specifically, time domain waveform of the signal is firstly obtained by time domain measurement equipments, such as oscillograph, and then based on the working principle of EMI receiver, mathematical software such as MATLAB is applied to analyze frequency spectrum of the under-tested signal. The proposed spectrum analysis method not only has advantages over the traditional EMI receiver with lower cost and shorter measurement time, but also can obtain the frequency spectrum of the short-time and frequency conversion signal precisely.