Efficient and Accurate Modeling of EMC Anechoic Chambers using a Combined Discrete Complex Image and Raytracing Method

摘要

The traditional approach to simulate an EMC chamber is by using Geometric Optics (GO) and raytracing. Full wave methods are impractical because of the large amount of computer resources needed. Extending the asymptotic method such as GO to low frequency and in near field, as is required to model an EMC chamber, has long been questioned. In this paper, we describe an improved algorithm by combining GO with the Discrete Complex Image Method (DCIM). We treat the absorbers as multilayered media so that DCIM can be applied to solve for the first order reflections in a more rigorous manner. For higher order reflections where the GO model is adequate, we adopt a visibility tree approach for the raytracing. This approach allows raytracing in an arbitrarily shaped chamber. Several real world case studies are presented to show the accuracy, speed, and flexibility of this method.