Prediction of radiated emission for complex systems under Realistic Operating Conditions

Today´s electronic devices are complex systems often consisting of different subsystems that tend to have radio frequency communication interfaces as well as interconnecting cables to auxiliary equipment required for electromagnetic compatibility testing. In many cases the subsystems are developed in different departments or even in different companies. This paper describes measurement techniques for such subsystems, including the possibility to establish radio frequency links to auxiliary equipment or other subsystems during the measurement of radiated emission. Based on transverse electromagnetic (TEM) waveguide measurements with the subsystems a prediction of the radiated emission of the complex system becomes possible before it´s prototype needs to be assembled. The analysis of the accumulated intermediate measurement data gives additional information for the optimization of the electromagnetic radiation of the system. An estimate for the directivity of each subsystem can be obtained.