Behavioral modeling and EMI analysis for airborne distance measuring equipment

Distance Measuring Equipment (DME) is one of the most useful navigation systems, and its performance such as stability and precision relates to the safety of an aircraft. As the electromagnetic environment of an aircraft is very complex, it is urgent to find out which kind of interference affects the DME seriously. This paper puts forward behavioral modeling to analyze the electromagnetic interference (EMI) existed in DME. By using behavioral model, the influence of pulse noise, narrowband noise and fluctuation noise to the performance of DME can be shown. The simulation result from ADS (Advanced Design System) shows that in time domain the pulse noise affects in a very short time and the fluctuation noise usually in low level lead to less EMI problem. And the in-band narrowband noise leads to EMI problem commonly, which accords with the real fact. So it turns out that behavioral modeling is a useful method to analyze EMI problems in a circuit or a system.