Measurements as Enhancement of Numerical Simulation for Antenna Placement on a Rotocraft

EM antenna performances in large and complex scenarios are often evaluated by Computational Electromagnetics (CEM) solvers based on the Domain Decomposition Technique (DDT), in which the radiating antennas are studied separately and then antennas are integrated as radiating sources in the numerical simulation of the entire scenario [1]. Such approach based on only simulations is commonly practiced during designing process and in general when a measurement of entire system cannot be done. Recently, an approach has been presented that combines simulations and measurements by exploiting the potentialities of both tools [2]-[3]. Due to the conclusiveness and high reliability of actual measured data, antenna measurements can be used as accurate radiation sources in numerical simulations. The usage of measured data to characterize the radiators, as well as including more realistic antenna data in the simulations, also helps to overcome the limitation that a full wave model of the antenna (or electrical and mechanical design) is not available due to intellectual property issues or when measuring the entire scenario is not feasible. The measured sources are based on the expansion of the measured field using equivalent current method [4], [5] and then are compatible with different commercial CEM solvers. This paper presents a case study of how measurements can enhance numerical simulations for electrically large structures with particular attention to antenna placement on a rotorcraft model using measured source for the antenna.