Evaluation of Electromagnetic Time Reversal Spatial Focusing (EMTR-SF)

In this paper, we present two evaluation approaches of the electromagnetic time reversal technique spatial focusing (EMTR-SF). The first approach is based on measuring the spatial correlation function. This yields the diameter of the circle the power is focused on. Our experiments for a given reverberation chamber result in a 0.75λ focusing diameter. The second approach is based on the energy enhancement ratio (EER). This gives a physical insight into the amount of energy enhancement offered by EMTR. It also helps to determine the optimum pulse width for EMTR in a given environment. A maximum EER of 2.5× is measured for an optimum pulse width of 2 ns. Both evaluation approaches should be considered in order to properly asses and establish an efficient EMTR scheme.