Research On The Characteristic Of Antennas Under The Theory Of Transformation Optic

With the prosperous development of the transformation optic theory, it makes the dream of control the light’s propagation become reality. As the key method of transformation optic theory---coordinate transformation is gradually used in the electromagnetic device’s study, among them, the most famous example is invisible cloak. Then some scholars proposed that the coordinate transformation method can be the theoretical direction when designing the conformed antenna. However, almost of the related research is about the equivalent of ideal electromagnetic source, it will be a quite challenged question about how to get the research of real antenna form ideal electromagnetic source.In this paper, the transformation optic theory is used, and the coordinate transformation formulas applied to the feeding gap were deduced by the method of coordinate transformation and boundary conditions. Then by means of four different antenna models to verification the accuracy of the formula, consequently proved the feasibility of the research about conformal antenna by transformation optic method at the same time. The main work and innovation point of this work contains below parts:1. According to the formula which was used on ideal electromagnetic source, and by means of boundary conditions and Greens function, the transformation formula of feeding field on line antenna and surface antenna was separately deduced. It can be found from the formula that the transformed antenna can bring into the correspondence with the original antenna by changing the feeding field following the formula used on source. This formula makes the transition from the research of ideal electromagnetic source to antenna.2. The feeding formula was used on2D ideal line antenna Pinwheel model, and the model was simulated by the electromagnetic simulation software COMSOL. The equivalence of radiation feature between original antenna and transformed antenna can be validated according to the simulation results, and the accuracy of the feeding formula was verified at the same time.3. This paper further proposed actual line antenna model in3D. The first one is spherical dipole antenna model. By the simulation of the software, get the conclusion that the transformed antenna has the same radiation field as the original one. Then the paper uses an embedded monopole antenna model to verify the equivalence, and proposed a simple way in designing transformed antenna. These two models not only verified the correctness of feeding formula, but all so can linking theory with practice that it makes the feasibility to design conformal antenna in reality works.4. Because of the widely use of microstrip antenna in conformal design, a model describing a transformation from plane microstrip antenna to a spherical one was proposed in this paper. The simulation result verified the correctness of feeding field coordinate transformation formula which was used on the tangent direction of feeding mouth on antenna. According to the simulation result, the antenna realized the equivalent conformal conversion. As the microstrip antenna is the first choice in designing conformal antenna, so this the simulation of this model become an even more simple and effective means in all methods.