Finite-difference time-domain method for electromagnetic radiation, interference, and interaction with complex structures

The finite-difference-time-domain (FDTD) method is reviewed and then used to model and predict the radiation patterns of a monopole antenna mounted on the bottom of a perfectly conducting helicopter structure. The computed radiation patterns are compared with measurements to demonstrate the accuracy of the FDTD method. To study the effect of antenna interference, a second monopole antenna is mounted on the structure and the patterns are recalculated. The perfectly conducting helicopter model is then replaced by a partially composite/partially conducting material structure and the electromagnetic fields penetrating the structure from an incident plane wave are analyzed. A preprocessing geometry program, GEOM, is used to generate an FDTD geometry model, assuming solid surface helicopter structure.