Development and implementation of SBR technique for scattering and RCS problems

Abstract

Full wave solution techniques are preferred to calculate the electromagnetic characteristic of an object. These methods give very accurate results. However, when the object is electrically large regarding wavelength, computation time may take very long, or required computer resources may not be provided. In this case, high-frequency approximation techniques are employed to solve electromagnetic scattering problems involving electrically large objects. Shooting and Bouncing Ray (SBR) method is a high-frequency technique that combines Geometric Optics (GO) and Physical Optics (PO). It can be used for the solution of electrically large objects. Multiple re ection feature of SBR makes it possible to calculate current distribution accurately on the target for the complex objects. In this study, an SBR code is developed in MATLABR which solves di erent kinds of problems that involve electrically large objects. Required formulas are derived and implementation procedure of the code is discussed. Radar Cross Section (RCS) of some basic shapes is calculated using SBR. An RCS reduction technique is explained and implemented. As the antenna-platform interaction, di erent kind of antennas are placed on a tank-like and a ship-like object to observe the e ect of a scatterer on antenna pattern. An antenna coupling formula is derived. This formula is used to calculate coupling between two antennas in di erent environments. Results show fairly good agreement with Method of Moment (MoM) solutions.