A Comparison of the Currents Induced on an EUT in a TEM Cell to Those Induced in a Free-Space Environment

The finite-difference time-domain method is used to investigate whether the currents induced on equipment under test (EUT) in a transverse electromagnetic (TEM) cell are similar to those induced in a free-space environment. The approach is to simulate an identical EUT in both environments and determine a correlation based on the respective current distributions. The effect of the ratio of EUT to TEM cell sizes on the correlation to free space is also investigated. This paper introduces a metric that quantifies the change in the surface current induced on the EUT in these different environments.