RCS of a partially open rectangular box in the resonant region

The radar cross section (RCS) of a partially open rectangular box in the resonant region is investigated. Two-dimensional numerical results are generated using the method-of-moments solution to the electric field integral equation. Resonance spikes are found in the RCS spectrum at frequencies which correspond to the resonant frequencies of the interior rectangular cavity. The dependence of the resonant behavior on the box dimension, aperture size, and incident polarization can be interpreted in terms of the field distribution inside the cavity. Experimental data for a three-dimensional box are also presented. They are consistent with the two-dimensional simulation