IEEE SCV EMCS Chapter

Using the FFT-based measurement systems for EMI testing can reduce test time, improve the repeatability of EMI tests. With the availability of high speed high resolution ADCs and large computation power today FFT-based measurement systems exceed the performance of traditional EMI receivers, regarding noise floor, measurement speed and accuracy. Today a real-time analysis bandwidth up to 1000 MHz for Quasi-Peak in full compliance mode is available, reducing the test time from 9 hours down to 1 second. Such a Technology can be used to speed up Full compliance testing. Such a system can be used to measure extremely accurate radiation patterns. Using correlation analysis of such patterns allows identifying radiation direction of individual sources and the effect of EMI measures that have applied. EMC Debugging on a complete system can be carried out based on the identification of sources. Another topic is the EMI measurement in presence of ambient noise. During the presentation a dual channel FFT-based EMI measurement system is presented. While the first antenna receives the signal of the EUT and the ambient noise, the second antenna only receives the ambient noise. By using a wideband LMS filter algorithm it is possible to cancel the ambient noise and show the EMI of the EUT. Measurement results show that typical ambient noise signals can be suppressed and even modulated signals of an EUT that are masked by ambient noise can be recovered. The system can cancel ambient noise with a bandwidth of more than 100 MHz. During the presentation the possibility for full compliance testing and the limitations of such a system are discussed. Speaker(s): Stephan Braun, Agenda: 5:30-6:15: Food/Social 6:15-6:20 Admin, call for nomination for officers 6:20: Start of presentation 1120 Fulton Pl, Fremont, California, United States, 94539