A novel technique for solving EMI/EMC problem between large antennas mounted on complex platforms

The EMI/EMC problem that affects the co-siting of antennas mounted on complex platforms is a very challenging one, especially when the body on which the antennas are mounted is large - as are the antennas themselves - and the separation distance between them is also many wavelengths in dimension. The objective of this paper is to present a novel technique for handling such large problems. Some examples of such problems are shown that display phased arrays and other antennas mounted on ships and airplane structures. One obvious approach to handling a problem with many degrees of freedom (DOFs) is to simulate it on a large parallel machine, e.g., a Beowulf cluster. Through such parallel processing helps expand the range of problem sizes that can be solved directly, many real-world problems still remain beyond our reach, often forcing us to make unreasonable approximations that cannot be fully justified. To address such coupling problems between arrays, we have developed a technique that modifies the parallel FDTD algorithm (the FDTD is chosen because it is a general-purpose code well-suited for analyzing complex and inhomogeneous structures) in a manner that enables the solving of the original problem in several successive steps, circumventing the need to deal with it in a single simulation, which would be prohibitive to carry out when the problem size is very large