Modified edge current method for high frequency scattering problems

Abstract

Optimization of high frequency antenna systems is impossible without efficient numerical method for direct calculation of antenna characteristics and radiated fields. Over the past 40–50 years, research in the field of high-frequency (HF) wave scattering from various objects with complex geometry and material filling, was focused on development of the methods accounting diffraction effects on the edges accurately, using high-frequency asymptotic techniques, such as Keller's Geometrical Theory of Edge Diffraction (GTD), Physical Theory of Diffraction (PTD), method of Physical Optics (PO) and the Method of Equivalent Currents (MEC). It can be shown, that these methods usually generate the most simple calculation formulas, but give inaccurate results outside backscattering direction. This paper proposes a hybrid method based on MoM, PO and modified MEC, which takes into account contribution of electric and magnetic edge currents, calculated using method of Induced Electromotive Force (EMF), into the scattered field. It is shown that, in contrast to the methods outlined above, the values of proposed edge currents are independent on the direction of radiation.