Aircraft EWIS Electromagnetic Interference wiring Research

A majority of EMI of airborne electronic equipment result from serious electromagnetic coupling caused by improper wiring of aircraft EWIS [1]. Based on detailed analysis of the theory of cable electromagnetic coupling and forecasting simulation, this paper summarized several factors that affect the electromagnetic coupling, such as distension between wires, height from the reference ground and impedance matching, and several related suggestions were given to reduce electromagnetic interference between cables or wires. In order to meet the airworthiness standards of EWIS composed in subpart H, FAR part 25, those suggestions can be as a reference of the design of aircraft EWIS wiring to improve the electromagnetic compatibility of aircraft electronic systems.