A Time-Reversal Method for Time-Harmonic Electromagnetic Source Reconstruction

The time-reversal (TR) method has been proven effective in reconstructing sources due to its spatiotemporal focusing properties. Much work so far on the topic has been conducted with sources of specific frequency bandwidths. However, most sources in practical situations are time-harmonic or single frequency. This letter proposes a novel approach to address this challenge by analyzing the TR method in the frequency domain and modifying it to derive a source condition for single-frequency sources. The proposed method is validated through numerical examples, demonstrating its effectiveness in source reconstruction. This work provides an alternative pathway for further development of practical electromagnetic source reconstruction techniques and testing systems.