Transparent Shells — Invisible to Electro - Magnetic Waves

In this paper, we study metamaterial-based transparent shells, which are invisible to electromagnetic waves and fields. More general topics, including material loss, material discretization and far field distribution etc. are covered in order to facilitate possible realization. We design and analyze the transparent shells using optical transformation. Unlike the widely-studied cloaking devices which make the objects inside invisible, the transparent shells physically cover and shield the devices inside without sacrifice of their electrical performance since they are transparent to incoming electromagnetic waves. Due to the simple constitutive parameters, these transparent structures could be realized using artificial metamaterials in a wide frequency band, which may have wide applications in civil and military areas.