Plane wave scattering from a cylindrical Helmholtz resonator: Dirichlet case

摘要

The problem of scattering of a plane electromagnetic wave by a cylindrical Helmholtz resonator, which is simply an infinitely long conducting cylindrical tube with an azimuthal aperture on its outer periphery, is studied by a Green's function approach for the Dirichlet boundary condition. Numerical results for the total scattering cross-section normalized with respect to the total scattering cross-section of a cylinder with no aperture clearly indicate the resonance characteristics of the structure. The resonance peak is observed to be extremely narrow for narrow opening sizes and as the aperture size is increased, the magnitude of the peak decreases and the location of the peak shifts to a higher value of ka. A comparison of the normalized total scattering cross section for different values of the angle of incidence is made. Graphical results for the field distribution inside the resonator are also presented.