The Design Of Novel Electromagnetic Device And Experimental Research Based On Transformation Optics

Since Pendry et al. and Leonhardt proposed the theory of transformation optics and used it to design a electromagnetic cloak in 2006, metamaterials along with transformation optics have become one of the most popular topics in the science and engineering community. The transformation optics method, which is based on time invariant coordinate transformation of Maxwell’s equations, is a theory to control the propagation of the electromagnetic field precisely. It has been widely used for the design of metamaterials and novel electromagnetic devices. In this article, we begin with the fundamental principles of transformation optics, and mainly focus on novel electromagnetic devices discussed in the following.Based on metamaterials and the theory of transmission line, we designed an open two-dimensional rectangular resonator. Through reasonable design, metamaterials can show its unique character, showing that the open two-dimensional rectangular cavity can be equivalent to a closed case.Using the optical transformation and equivalent medium theory, as well as classical electromagnetical analysis method, we used lattice array structure, which integrated of superconducting materials and magnetic materials, to designed the invisible carpet cloak. The full wave simulation results confirm the validity and effectiveness of the method.In the end, we focused on the relevant theoretical study of the anticloak. At present a large number of the invisibility cloak devices have been already designed. However, the experimental verifications of the anticloak and transparent cloak have not been reported. In this work, we give the first experimental verification of the anticloak. In particular, three experiments are conducted, corresponding to the cases of original object, the cloaked object, and the anticloaked object, respectively. The switchable functionalities of the invisibility cloak, the anticloak, and the transparent cloak are demonstrated using manual switches on the PCB board, which can be further improved using electronic switches. The measured results agree well with finite-element numerical simulations and circuit simulations.Our study shows that transformation optics is a powerful tool in the design of the novel electromagnetic device. In the whole process of the design, the crucial step is to seek the proper transformation functions in order to configure the parameters of the particular medium, i.e. permittivity and permeability. A breakthrough is that we use the experiment to demonstrate anticloak and transparent cloak, which further promotes the research of controlling of electromagnetic wave and better application of these novel electromagnetic devices.