ACAP: Antenna Coupling Analysis Program

ACAP has been developed to evaluate the, electromagnetic compatibility (EMC) of transmitting and receiving equipments installed on aircraft when the interferent situation is caused by coupling between their antennas. The external electromagnetic environment created by the antennas installed an the aircraft is simulated on the basis of the mathematical models of the fuselage shape and of the transmitters emissions. Theoretical models of the receivers sensitivities are used to control the EMC of susceptible equipments when located in such an environment. The program works in the frequency domain. The models, the methodology and applied techniques for the antenna-to-antenna electromagnetic analysis, including path loss around fuselage, are discussed. An optional possibility of analyzing interferent situation arising from intermodulation products is available in the program. Useful indications have been obtained from the ACAP results about the definition of transmitter and receiver EMC characteristics and about the choice of antenna locations on aircrafts. Actual results of an analyzed airplane are presented.