Near‐field characteristic verification for non‐reciprocity radome

We propose a nonreciprocal metasurface designed to suppress reflections in antennas, which have become a major source of electromagnetic interference with the increasing use of electromagnetic waves. A nonreciprocal metasurface capable of controlling transmission and blocking based on the propagation direction can play a crucial role in maintaining antenna performance while mitigating electromagnetic interference. The proposed nonreciprocal structure introduces nonreciprocity by incorporating a magnetic material into a conventional radio wave filter, enabling effective operation in both the far-field and near-field regions. In this study, we verify the near-field operation of a nonreciprocal metasurface, demonstrating an isolation of more than 10 dB at 6.3 GHz using a 6 GHz band antenna. Additionally, we report the effects of the metasurface on the antenna radiation pattern.