Focusing Time-Harmonic Scalar Fields in Complex Scenarios: A Comparison

This letter deals with the problem of focusing a time-harmonic wave into a target point embedded into a known complex scenario. In particular, we compare the performances of the Time Reversal approach and the Optimal Constrained Focusing technique, which relies on the formulation of the focusing problem in terms of convex programming. Both techniques guarantee a fast and adaptive design of effective applicators, but the second one allows to control the sidelobes of the field, providing a higher selectivity and a more flexible shaping of the field. Some numerical examples relevant to microwave hyperthermia, including a case where the scenario at hand is not exactly known, are given to appraise the importance of this capability.