Browsing by Author "HAN, LT"

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E-POLARIZED SCATTERING FROM A CONDUCTING RECTANGULAR CYLINDER WITH AN INFINITE AXIAL SLOT FILLED BY A RESISTIVELY COATED DIELECTRIC STRIP
(1992-06-01)
WU, LK
;
HAN, LT
;
交大名義發表
;
傳播研究所
;
National Chiao Tung University
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 (e.g., R(S) = 188.5-OMEGA) which attenuates significantly the impinging wave. Poorer resonance damping performance is observed as the film resistance increases to 754-OMEGA 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 thal the resultant resonance spectrum is lower in strength and broader in bandwidth.
IMPLEMENTATION AND APPLICATION OF RESISTIVE SHEET BOUNDARY-CONDITION IN THE FINITE-DIFFERENCE TIME-DOMAIN METHOD
(1992-06-01)
WU, LK
;
HAN, LT
;
交大名義發表
;
傳播研究所
;
National Chiao Tung University
Use of resistive sheet boundary condition in the finite-difference time-domain (FDTD) analysis of scattering problems involving resistively coated dielectric object is described. The algorithm is introduced through an analysis of E-polarized scattering from a thin resistive strip. For the sheet resistance R = eta-Z0/2 with Z0 being the intrinsic impedance of vacuum, numerical experiments indicate that algorithm stability is ensured in all cases if delta-t is chosen according to c-eta-delta-t less-than-or-equal-to delta. Validity of the resultant FDTD method is verified in a comparison of computed E-polarized scattering data for several resistive strips with existing data. New results on the E-polarized scattering behavior of resistively coated dielectric strip as a function of surface resistances and angle of incidence are also presented. Finally, extension to the H-polarized case and application of the present method to pulsed problems are briefly discussed.