DIFFRACTION AND BACKSCATTERING OF ELECTRO MAGNETIC WAVES BY CIRCULAR DIELECTRIC DlSCS AT X-BAND

Abstract

The classical Kirchhoff's theory of diffraction by a circular  aperture in a conducting infinite screen is modified by taking into account the phase change introduced by the circular dielectric disc and also the effect of multiple internal reflections raking place inside the disc. The diffraction patterns thus obtained from appropriate vibration spirals and computed as function of the diameter and thickness of the disc agree well with the experimental diffraction patterns. The constructional details and characteristics of the image plane apparatus developed and used for the measurement of the diffraction patterns and back scattering cross-sections are discussed.