Modeling and Analysis of Anechoic Chamber Using CEM Tools

Abstract

Advances in computational resources facilitate anechoic chamber modeling and analysis at VHF/UHF frequencies using full-wave solvers available in commercial software such as FEKO. The measurement community has a substantial and increasing interest in utilizing computational electromagnetic (CEM) tools to minimize the financial and real estate resources required to design and construct a custom anechoic chamber without sacrificing performance. A full-wave simulation analysis such as the finite element method (FEM) provides a more accurate solution than the approximations inherent to asymptotic ray-tracing techniques such as physical optics (PO), which have traditionally been exploited to overcome computational resource limitations. An anechoic chamber is simulated with a rectangular down-range cross-section (in contrast with the traditional square cross-section) to utilize the software’s capability to assess polarization performance. The absorber layout within the anechoic chamber can be optimized using FEKO for minimal reflections and an acceptable axial ratio in the quiet zone. Numerical results of quiet zone disturbances and axial ratios are included for both low- and medium-gain source antennas over a broad frequency range.