Modeling and inverse parameter optimization of electromagnetic absorber for the design of anechoic chamber

Abstract

Nowadays, $a$ lot of the electromagnetic anechoic chamber manufactures supply the standard pyramidal absorbers, which can satisfy specified purpose. Electrical parameter is an important factor that defining the absorption effect of the absorbers. A full-waveform inverse parameter optimization method is developed and implemented for the pyramidal absorber model. Using the finite difference time domain (FDTD) forward modeling data and the inverse parameter optimization method, the optimized parameters are searched. During the forward modeling, the Complex Frequency Shifted- Perfect matched layer (CFS-PML) and Periodic boundary conditions are applied to limit the computation domain. We discuss the reflection levels of the pyramidal absorbers. After getting the optimized parameters of the pyramidal absorber, a planar near-field anechoic chamber is designed and studied with FDTD method to verify the efficiency of the parameter optimization method. The results show that the inverse parameter optimization method works well and can help the anechoic chamber absorb the electromagnetic waves efficiently. In this paper, we mainly focus on the study about computational method of the electromagnetic absorber to find the optimized electrical parameter. In the future, we will consider to apply these methods to the real measured data study and help the manufactures to improve the properties of the absorbers.