A Broadband Time-Domain EMI Measurement System for Measurements up to 18 GHz

摘要

Using time-domain methods, emission measurements can be accelerated by several orders of magnitude in comparison to measurements with traditional EMI-receivers. In this paper, a novel time-domain EMI measurement system for the frequency range from 9 kHz to 18 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. With a 9 kHz IF-filter, a measurement over the whole frequency range can be performed in around three minutes with highest sensitivity. The results of the noisefloor measurements imply, that the system, with its low noise figure of 6-8 dB, meets the enhanced sensitivity requirements over the whole frequency range up to 18 GHz.