Scatterers with resonant cavities

An analysis of the characteristic properties of scatterers with resonant cavities has been carried out based on the solution of the corresponding boundary value problem. The two-dimensional case of structures formed by a collection of thin screens having cavities coupled with each other and exterior space through apertures has been considered. It is shown that the cavity-to-cavity coupling causes a transformation of the resonance scattering and, consequently, the scattering properties of structures formed by strongly coupled resonant scatterers can be different from the properties of structures formed by uncoupled or weakly coupled elements. The spectral problem of determination of the complex-valued eigenfrequencies of the structures has been solved and the results of the analysis of the discrete spectra has been used in the study of the scattering phenomena. It has been shown that the mutual location of the scatterers can lead to the energy storage in the vicinity of the structure and as as a result to the very high level of the radar cross-section in a narrow frequency band. The research is focused on the determination of physical processes which characterize the scattering properties of the structures formed by several resonance elements and on particular resonances of the scattered field caused by the interaction of the elements.