Prediction of Equipment-to-Equipment Coupling Through Antennas Mounted on An Aircraft

Abstract

Modern military and civil aircraft have various radar and communication equipments placed on them for different actions. Electromagnetic interference (EMI) can be easily coupled through various antennas which are mounted on the aircraft. It is therefore desirable to exactly predict their effect on one another as much as possible. In this paper the equipment-to-equipment coupling (ETEC) is proposed which is suitable to accurately determine the electromagnetic compatibility (EMC) safety margin of the aircraft radio system. By employing the microwave network theory the equivalent circuit model of the Identification Friend or Foe System (IFFS) and the Ground-to-Air (GTA) communication system of the aircraft can be obtained and then the ETEC is accurately calculated. In this way the electromagnetic coupling level between the two subsystems can be easily determined. Basing on the accurate coupling, it is allowed to simply and exactly evaluate the electromagnetic interference safety margin of the receiver.