Infinitesimal Dipole Model Using Space Mapping Optimization for Antenna Placement

The infinitesimal dipole model (IDM) is very appealing for antenna placement problems, especially since antenna design details need not be available. The method has been mainly used to model antennas radiating in free space or above an infinite perfectly conducting ground plane, with synthetic data. The direct application of the method considering finite ground planes is impracticable because of the complexity of the associated Green's functions. In this letter, we propose a methodology to devise the equivalent model, taking into account edge diffraction effects due to the finite ground plane, but still maintaining a relatively low computational cost. We combine the classical IDM with the output space mapping technique so that the burden of model optimization is placed on the analytical model, and the more accurate but computationally intensive model is evaluated only a few times. To demonstrate the applicability of the method, we model a radar altimeter antenna operating at 4.3 GHz in a typical case of antenna integration: Only the measured far-field data are available. The equivalent model obtained is then incorporated into a commercial electromagnetic simulation package to compare its installed radiation pattern with the actual antenna measured pattern. An excellent agreement is verified.