A model for predicting the reflection coefficient for hollow pyramidal absorbers

We present an expression for the effective material properties of electromagnetic hollow pyramidal absorbers. This expression can be used to efficiently calculate the reflection coefficient of this absorbing structure. The reflection coefficients based on this model have been compared to and closely agree with calculated finite element results. We show how the reflection coefficient varies as a function of the absorber wall thickness. Measurement data for a hollow absorber obtained using time-domain measurement techniques are also presented.