Key Laboratory of Ocean Observation-Imaging Testbed of Zhejiang Province, Institute of Marin Electronics Engineering, Ocean College, Zhejiang University, Hangzhou, P. R. China
Key Laboratory of Ocean Observation-Imaging Testbed of Zhejiang Province, Institute of Marin Electronics Engineering, Ocean College, Zhejiang University, Hangzhou, P. R. China
Key Laboratory of Ocean Observation-Imaging Testbed of Zhejiang Province, Institute of Marin Electronics Engineering, Ocean College, Zhejiang University, Hangzhou, P. R. China
Unidirectional cloaks or carpet cloaks have become an essential branch of invisibility cloaks due to non-extreme parameters that are relatively easy for realization and potential applications. So far, a unidirectional cloak for transverse electric (TE) polarized wave has been successfully realized to hide an object in the air along a single direction with almost ideal performance. However, a practical method to achieve a unidirectional cloak for transverse magnetic (TM) polarization is still missing. In this paper, we successfully have designed, fabricated, and measured a full-parameter unidirectional TM-wave cloak in free space. In comparison to the previously-realized TE-wave counterpart, our cloak uses a perfect electric conductor boundary to obey the free-space symmetry condition of the TM incident wave and is therefore much more convenient to fabricate. The cloaking performance of the fabricated sample has been demonstrated via both full-wave numerical simulation and near-field measurement.
