A new model for calculating diffraction fields, in urban environments, using physical optics approach

Major methods that were recently used for solving the electromagnetic field in the urban environment based on approximation methods named GTD,UTD,GO. With attention that these methods are obtained from the Maxwell equations by using the approximation and asymptotic methods, for many applications validity of them is limited. Although these models have variation about wavelength of field but this variation of field is not same as real field variation. Recently mobile systems have become smaller and smaller, and on the other hand must have excellent accuracy. Therefore it is necessary that better methods are used. With generalize the methods are used for field calculation in front of antennas and extended apertures this is possible to reach more accurate models.