The method of decomposition of the time reversal operator has been introduced with the aim of focusing acoustic waves on a selected target. It is based on the derivation of the invariants of the time reversal operator, which is linked to the transfer matrix of the array of transducers insonifying a time invariant scattering medium. The theoretical and numerical results concern independent point-like scatterers. Here, we apply numerically the same technique to electromagnetic waves, and all the interactions between the various scatterers are taken into account. This method may be very useful to detect and localize buried objects. With this goal, we have investigated the role of polarization and of the geometrical or electromagnetic parameters, as well as the ability of accurately focusing on a scatterer. The sensitivity of the results to the initial set of data, namely the number of measurements or the accuracy, is also studied.