Near and far field comparison using wire-grid and patch models

This thesis examines the accuracy of near field computations obtained using wire grid and surface patch method of moments models. Wire grid results were obtained using NEC, a point matching implementation, and MBC, a Galerkin implementation. The surface patch results were obtained using Junction. In the near field, a flat plate and a sphere illuminated with an incident plane wave are investigated. For the far field examinations, wire grid models examine the radar cross section of two flat plates as well as the radiation pattern of a monopole mounted on a sphere. In addition, a high frequency band sweep of a helicopter model is performed.; Good near field results are obtained using wire grid models so long as the field points are not too close to the wires. Patch models allow field points much closer to the surface since the current is distributed over the surface. Excellent far field results are obtained for both the plate and the sphere. The frequency sweep generally showed good results though anomalies were evident at certain frequencies.; Wire grid results were obtained using NEC and MBC though the results indicate that the type of Moment Method formulation for wire grids was not a major factor. Surface patch results obtained with Junction were used to validate the wire grid near field plate results. Validation for the sphere is by an exact solution.