Basic Electromagnetic Interference Measurements on Automobiles

The paper discusses the SAE Technical Program on RFI Measurements and is basically a tutorial review of radio frequency interference/electromagnetic interference (RFI/EMI) measurements on automobiles. The text is designed to provide engineers and technicians not familiar with RFI/EMI measurements with a basic appreciation of the measurements, the terminology used, the reasons for measurements, and how measured data should be presented. SAE Standard J551a is discussed. Given are background and data on basic descriptions of EMI and its effects on the environment; the basic history of electric field measurements and antennas; characteristics of receivers-including descriptions of heterodyning, mixing, peak detection, average detection, and quasi-peak detection-and a brief history of EMI receivers.