|
''Artificial dielectrics'' are fabricated electromagnetic materials consisting of synthetic substances, usually constructed in an orderly arrangement, such as arrays. The arranged materials, and the distances between them are usually evenly spaced on, or within, a substrate. Hence, the arrays of inclusions are in a periodic or lattice structure. Also, the lattice spacing is smaller than the impinging electromagnetic wavelength. These were first conceptualized, constructed and deployed for interaction in the microwave frequency range in the 1940s and 1950s. The constructed medium, the artificial dielectric, has an effective permittivity and effective permeability, as intended.〔 First published in 2004 according to the (CRC Press web page ) for this book. According to the copyright page of this book, accessible via Google Books, it had gone into its tenth printing by sometime in 2005.〕〔 In addition, some artificial dielectrics may consist of irregular lattices, random mixtures, or a non-uniform concentration of particles. Artificial dielectrics came into use with the radar microwave technologies developed between the 1940s and 1970s. The term "artificial dielectrics" came into use because these are macroscopic analogues of naturally occurring dielectrics. The difference between the natural and artificial substance is that the atoms or molecules are artificially (human) constructed materials. Artificial dielectrics were proposed because of the need for lightweight structures and components for various microwave delivery devices. Artificial dielectrics are a direct historical link to metamaterials. ==Seminal work== The term artificial dielectric was originated by Winston E. Kock in 1948 when he was employed by Bell Laboratories. It described materials of practical dimensions that imitated the electromagnetic response of natural dielectric solids. The artificial dielectrics were borne out of a need for lightweight low loss materials for large and otherwise heavy devices.〔〔〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「artificial dielectrics」の詳細全文を読む スポンサード リンク
|