Quasi-analytical Near-to-Far Field Transformation Based on Field Matching Method for Scattering Problems

A new quasi-analytical near-to-far field transformation based on field matching method (field expansion in a base of Hankel functions) is presented. This approach uses finite element method to obtain near field, then the field is expressed in a base of Hankel functions. The evaluated coefficients allow to calculate the field outside the numerical domain, also in a far distance. The main advantage of the proposed technique is avoiding of the Green’s function integration. The method can be applied for obstacles of an arbitrary cross section and homogeneous in one direction. In order to confirm the validity of the presented technique three different structures were analyzed and the results were verified with the other methods.