Extended Stationary Phase Method based on Fresnel functions for the calculation of three-dimensional scattering of electromagnetic waves from rectangular perfectly conducting plates

The aim of this paper is to present an extension over a novel three dimensional high frequency method for the calculation of the scattered electromagnetic (EM) field from a Perfect Electric Conductor (PEC) plate, which is based on the Physical Optics (PO) approximation and the Stationary Phase Method (SPM). This method has been presented only recently, showing fast and satisfactory results, nevertheless its accuracy around the area of the main scattering lobe may further be enhanced. The extension proposed here is utilizing higher order approximation terms, which imply the use of Fresnel functions in order to optimize the results without any load in time efficiency, since our initial goal is to present a complete analytical method that produces accurate results without sacrificing the calculation time, which is very important for the practical use of radio-propagation tools.