In an electromagnetic cloak based on a transformation approach, reduced sets of material properties are generally favored due to their easier implementation in reality, although a seemingly inevitable drawback of undesired reflection exists in such cloaks. Here we suggest using high-order transformations to create smooth moduli at the outer boundary of the cloak, therefore completely eliminating the detrimental scattering within the limit of geometric Optics. We apply this scheme to a non-magnetic cylindrical cloak and demonstrate that the scattered field is reduced substantially in a cloak with optimal quadratic transformation as compared to its linear counterpart.
标签： electromagnetic transformation properties approach
上传时间： 2017-03-30
上传用户：pkkkkp
We obtained the energy transport velocity distribution for a three dimensional ideal cloak explicitly. Near the operation frequency, the energy transport velocity has rather peculiar distribution. The velocity along a line joining the origin of the cloak is a constant, while the velocity approaches zero at the inner boundary of the cloak. A ray pointing right into the origin of the cloak will experience abrupt changes of velocities when it impinges on the inner surface of the cloak. This peculiar distribution causes long time delays for beams passing through the ideal cloak within a geometric Optics description.
标签： distribution dimensional transport obtained
上传时间： 2013-12-19
上传用户：zhliu007
This book describes the applications of the fundamental interactions of electromagnetic waves and materials as described in the preceding volume, “Basic Electromagnetism and Materials”. It is addressed to students studying masters or doctorate courses in electronics, electromagnetism, applied physics, materials physics, or chemical physics. In particular, this volume analyzes the behavior of materials in the presence of an electromagnetic field and related applications in the fields of electronics, Optics, and materials physics.
标签： Electromagnetism Materials Applied and
上传时间： 2020-05-26
上传用户：shancjb
The field of digital communication has evolved rapidly in the past few decades, with commercial applications proliferating in wireline communi- cation networks (e.g., digital subscriber loop, cable, fiber Optics), wireless communication (e.g., cell phones and wireless local area networks), and stor- age media (e.g., compact discs, hard drives). The typical undergraduate and graduate student is drawn to the field because of these applications, but is often intimidated by the mathematical background necessary to understand communication theory.
标签： Communication Fundamentals Digital of
上传时间： 2020-05-27
上传用户：shancjb
The use of optical free-space emissions to provide indoor wireless commu- nications has been studied extensively since the pioneering work of Gfeller and Bapst in 1979 [1]. These studies have been invariably interdisciplinary in- volving such far flung areas such as Optics design‚ indoor propagation studies‚ electronics design‚ communications systems design among others. The focus of this text is on the design of communications systems for indoor wireless optical channels. Signalling techniques developed for wired fibre optic net- works are seldom efficient since they do not consider the bandwidth restricted nature of the wireless optical channel.
标签： Communication Wireless Optical Systems
上传时间： 2020-06-01
上传用户：shancjb
