Abstract
Over a long time since the proposal of metamaterials, their exotic EM properties have been conventionally characterized by continuous effective medium parameters. That is to say, the theories and technologies for tailoring EM waves still stay on the physical level. In 2014, this limitation was broken by the emergence of digital coding metamaterial and the development of metamaterial is thus extended from the physical world to the digital world, bringing forth a brand-new concept—information metamaterial. Characterized by binary codes and equipped with digital hardware, the information metamaterial can do far more than just the manipulation of EM waves; through direct interactions and operations with digital signals within EM fields, information processing, transmission, or even recognition can be possible. The significance to the EM community is manifested by the emergence of new types of components and devices and the proposal of information theories, operational theorems, and the transformation of system architectures for wireless communication. Today, the information metamaterial has grown up gradually to become an independent subject of metamaterials. This chapter presents basic concepts, theories, principles, techniques, and typical applications of the information metamaterials and metasurfaces in detail, from which readers can understand the topic. Finally, the chapter is closed by summarizing the development track of the information metamaterial.
