Microwave Simulation of Reflection and Scattering by Pits on Optical Disks

Abstract

The Simulation of scattered far-field patterns by three-dimensional models of pits on brass plates were carried out using a microwave beam with a frequency of 50 GHz. The dependence of the scattered field patterns on the pit form, depth and size were examined. They were almost independent of the pit aperture forms (for example, circular, square and rectangular) with the same area. The power level of the main lobe corresponding to specular reflection became a minimum at a pit depth of h\\fallingdotseq0.3 λ, where λ is the microwave wavelength, and an aperture size of a\\fallingdotseq0.8 σ, where σ is the beam width. Simultaneously, the levels of the side lobes were at a maximum. The measured fields of the main lobe were in good agreement with those calculated using the Kirchhoff approximation.