A time-domain EMI measurement system up to 26 GHz with amplitude probability distribution

In this paper, a low-noise time-domain electromagnetic interference (EMI) measurement system for the frequency range from 9 kHz - 26 GHz is presented. It combines ultra-fast analog-to-digital-conversion and real-time digital signal processing on a field-programmable-gate-array (FPGA) with ultra-broadband multi-stage down-conversion. Scan time is decreased by several orders of magnitude compared to traditional EMI receivers. Non-stationary signals can be measured via the broadband, real-time spectrogram with a bandwidth of 162.5 MHz. The implemented multichannel amplitude probability distribution function (APD) allows for the evaluation of the statistical properties of broadband digital communication services.