Electromagnetic Wave Transmission through Sub-wavelength Channels and Bends Using Metallic Wires

Abstract

Techniques and technologies to transfer electromagnetic energy through sub-wavelength channels have been researched extensively in the past few years because their application in different areas such as sub-wavelength imaging, telecommunication, increasing the storage capacity, and confinement and transmission of electromagnetic energy. Common ways of achieving such transmission includes exciting surface plasmon polaritons on both sides of the cannel or using double negative metamaterials. Recently a mechanism to squeeze the electromagnetic energy through sub-wavelength channels using materials with extremely small permittivity was introduced. Such materials may be found naturally at some limited frequencies in the infrared and optical frequency ranges, but they are commonly fabricated for a desired frequency as engineered metamaterials by by embedding metallic inclusions in a dielectric medium. The main problem with the engineered materials is that they have relatively large losses at their low permittivity frequency. In this thesis,I have presented a novel structure consisting of arrays of metallic wires that can be used to squeeze electromagnetic energy through sub-wavelength channels and junctions with negligible loss. The theory of transmission through such array is derived and design methods to tune the transmission frequency is provided. The structure is also tested numerically and experimentally in several geometries and results are compared with previous methods.