E-polarized scattering from a conducting rectangular cylinder with an infinite axial slot filled by a resistively coated dielectric strip

The potential use of resistive films for damping the resonance spikes observed in the radar cross section (RCS) spectrum of a partially open rectangular cavity is investigated using a recently developed finite-difference-time-domain (FDTD) method that utilizes the resistive-sheet boundary condition for the modeling of resistive films. Backscattering data obtained in the first resonant region for an E-polarized plane wave normally incident into the slotted side of the cavity are presented. It is shown that resonance behaviors can be eliminated completely with a low-resistance film that attenuates significantly the impinging wave. Poorer resonance damping performance is observed as the film resistance increases because more of the field is allowed to penetrate into the cavity. For the latter case, the presence of the resistive film lowers the Q-factor of the slotted cavity such that the resultant resonance spectrum is lower in strength and broader in bandwidth.<
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