Diffraction patterns generated by conducting Cantor gratings

We present here a study of the Fraunhofer diffraction patterns produced by perfectly conducting surfaces that have a fractal profile of the Cantor bars type. The wavelength- minimum diffractive element ratio of this object is chosen in such a way that the scalar approximation for calculating the intensity distribution in the Fraunhofer plane is in principle no longer valid. We evaluate the diffraction pattern from both the FFT method and an electromagnetic vectorial method. The self-similarity features of the diffraction patterns obtained from these methods are calculated and the results are compared.