Near-field To Near/Far Field Transformation For Arbitrary Near-field Distribution Using An Equivalent Magnetic Current And MoM

Presented in this dissertation is a method for computering near-field and far-field characteristics of an EM source from its near-field measurements taken over an arbitrary shaped geometry, which can be applied to electromagnetic compatibility problem. This method utilizes near-field data to determined an equivalent magnetic current source over a fictitious surface which encompass the EM radiation source. This magnetic current, once determined, can be used to ascertain the near and the far field. This method demonstrates the concept of analytic continuity , once the value of the electric field is known for one region in space , from a theoretical perspective , its value for any other region can be extrapolated . An electric field integral equation is developed to relate the near fields to the equivalent magnetic current . A moment method procedure is employed to solve the integral equation by transforming it into a matrix equation . A least squares solution via singular value decomposition is used to solve the matrix equation . Computations with synthetic data , where the near field of several typical antenna configurations are got over various geometric surface , illustrate the accuracy of the method .