A Single-Frequency Time-Reversal Method for Electromagnetic Source Reconstruction

The time-reversal method has been applied to the source location due to its spatiotemporal focusing properties. Much work on the topic is to locate the impulse or wideband sources. However, most sources in practical situations are narrowband. Therefore, it is desirable to develop a single-frequency time-reversal method to reconstruct narrowband-source locations. Unlike the conventional time-reversal method, the single-frequency time-reversal method we propose in this paper extracts the field signals at a single frequency at the time-reversal-mirror locations and reinjects them into the solution domain for the backward simulations. The preliminary experimental results with an ergodic cavity demonstrate the effectiveness of our proposed method and move one crucial step forward for the practical uses of the time-reversal method. They lay the foundations for further extensions of time-reversal theory and applications.