Electromagnetic Coordinate Transformation And Its Application

The design of electromagnetic cloak based on coordinate transformation theory was firstly proposed by Pendry et al in 2006. Later, this theory was experimentally demonstrated by Schurig, which made the coordinate transformation and the phenomenon of cloaking a hot spot of scientific research. It was evaluated by Science as one of the year's top ten scientific and technology developments. Since then, many novel devices based coordination transformation were proposed to manipulate the propagation of electromagnetic wave.Based on the theory of coordination transformation, this thesis developed the material parameter equations for electromagnetic transparent devices and concentrators with arbitrary geometries. The influence of the material parameters on the characteristics of the devices was analyzed. Besides, the material parameter equation for the arbitrary shaped external cloak was derived. The performance of the external cloak based on linear and nonlinear coordinate transformations are compared with each other and discussed in detail. All the theoretical results were validated by numerical simulation using the finite element software COMSOL. The main contents and conclusions obtained are as follows.In the first part, the coordinate transformation theory was introduced, and its applicationin the design of arbitrary shaped electromagnetic cloak which hidden an object by enclosing it in the cloaking shell was discussed in detail.In the second part, material parameter equations for the transparent device with regular polygonal cross section as well as arbitrary cross section of conformal and non-conformal boundaries were developed, and validated by numerical simulation. The application of the transparent device in the protection of antenna was investigated.In the third part, the electromagnetic concentrator was studied. Material parameter equations for the elliptical concentrator, the regular polygonal concentrators as well as the arbitrary shaped concentrators with conformal and non-conformal inner and outer boundaries were developed and validated by numerical simulation. The phenomenon of field concentration of light plays an important role in the harnessing of light in solar cells similar devices. It is expected that this work is helpful for the designing concentrators in electromagnetic and optical fields, where high field intensities are required.In the fourth part, material parameter equations for the elliptical external cloak, regular polygonal external cloak, as well as the external cloak with arbitrary geometries were developed. The performance of the cloak based linear coordination transformation was studied and compared with that based on non linear transformation. It's found that the shape and size of the"antiobject"is dependent on the contour of the cloak and the coordination transformation. Interestingly, the object with much larger size can be hidden by the cloak based on non-linear transformation, which shows some advantages in open up an avenue for miniaturization in future cloak design.