Research Of Inverse Transformation Optics Theory Applied To Antenna Design

The transformation optics has set up a bridge between the artificial electromagnetic materials and the free manipulation of electromagnetic waves.Through the coordinate transformation,the transformation optics can design the material parameters of the transformation medium such that the electromagnetic waves via the transformation medium can be controlled in terms of the designer's expectations.In view of the capability of manipulating electromagnetic waves at will,the cross-over study combining transformation optics and the antenna design has gradually become a hotspot.Starting from the basic concept of transformation optics,then following with its related extension theory and taking the artificial electromagnetic material as a means of realization,a detailed theoretical analysis and simulation verification are presented in this thesis.The main contents and major innovations are as followings:1.In the context of transformation optics,a study is made on the application of impedance boundary condition.Under the assumption that conformal transformation is applied,the transformation formulas are deduced for the impedance boundary condition in the transformed space.2.Based on inverse transformation optics,the design of the conversion lens from propagating waves to surface wave is studied in details.The influences of different coordinate transformation and thickness on the radiation characteristics are analyzed.In addition,a transmitting lens of generating amulti-beam is proposed.3.Based on inverse transformation optics,a metasurface of generating multiple beams with dual polarization has designed.Through the reasonable approximation and effective simplification,the design can be easily realized by a compact structure consisting a multiple 2D metasurfaces.In this thesis,it is shown that the innovative research based on the theory of transformation optics and the artificial electromagnetic materials will bring new ideas and approaches for the flexible and effective control of the radiation characteristics of the antenna.