RCS of dielectric cubes and rods by FDTD and by measurement

This paper compares the RCS of plexiglas cubes and rods computed by the finite-difference time-domain(FDTD) method with the measured RCS. The measurement was done from 8 to 18 GHz, where the relative permittivity is approximately 2.3. Plexiglas is a relatively low-loss material and was approximated as lossless in the FDTD calculation. For each target the RCS was calculated with several values of εr and FDTD's RCS was found to be very sensitive to εr. FDTD traces out an intricate structure of peaks and sharp nulls. The calculated RCS shows good overall agreement with the measurement.