Transformation Optics-based Antennas

Shah Nawaz Burokur, André de Lustrac, Jianjia Yi, Paul-Henri Tichit

• Editore: ISTE Press - Elsevier
• Anno: 2016
• ISBN:
  9780081017715
• Argomento: Technik & Maschinenbau
• Categoria: Bauingenieurwesen

Transformation Optics-based Antennas is organized into two chapters that follow an introduction that presents the basic principles of the transformation optics concept. Two types of transformation are presented, coordinate transformation and space transformation. Implementations using metamaterials are also discussed.

Chapter One focuses on coordinate transformation in the design of devices capable of modifying the electromagnetic appearance of a radiating source. Transformation of a directive radiation pattern into an isotropic one (and vice-versa) through space stretching and compression, respectively, and the possibility of creating multiple beams are also studied.

Chapter Two deals with devices designed using space transformation concepts. Quasi-conformal transformation optics (QCTO) are applied for the design of lenses, either to compensate for the phase shift created by the conformation of an array of sources or to steer a beam to an off-normal direction.

• Focuses firstly on the theoretical tools that define transformation optics
• Address the origin of these concepts by analyzing Fermat's principle
• Details the basic approaches and methods needed to design practical applications of transformation optics concepts

1

Transformation Optics Concept: Definition and Tools

Abstract:

The exciting field of metamaterials has attracted the interest of researchers from all across the world over the past few years. With roots in the foundations of optics and electromagnetics, researchers are exploring the underlying physics of metamaterials. Electromagnetic metamaterials are artificially structured materials composed of periodic arrays of sub-wavelength resonating structures, scatterers or apertures, whose electric or magnetic response provides the ability to engineer dielectric or magnetic properties that do not exist in naturally occurring materials. The dielectric or magnetic properties can be tailored by changing the geometrical parameters of the constituent structure of the metamaterial.

Keywords

Coordinate transformation; Electric resonators; Magnetic resonators; Metamaterials; Quasi-conformal transformation optics (QCTO); Space transformation; Transformation Optics

1.1 State of the art on metamaterials

The exciting field of metamaterials has attracted the interest of researchers from all across the world over the past few years. With roots in the foundations of optics and electromagnetics, researchers are exploring the underlying physics of metamaterials. Electromagnetic metamaterials are artificially structured materials composed of periodic arrays of sub-wavelength resonating structures, scatterers or apertures, whose electric or magnetic response provides the ability to engineer dielectric or magnetic properties that do not exist in naturally occurring materials. The dielectric or magnetic properties can be tailored by changing the geometrical parameters of the constituent structure of the metamaterial.

Metamaterials has covered a wide variety of topics with a rich history of scientific exploration. A metamaterial is a microstructured material that is patterned to achieve a desired interaction with some wave-type phenomena, and is usually either acoustic or electromagnetic. The electromagnetic metamaterials studied and applied in this book mainly concern the engineering of unusual permittivity and permeability values such as negative or less than unity.

The recent surge in interest in metamaterials, however, has been fueled by experimental and theoretical demonstrations of physical phenomena, resulting from this patterning, which mimic materials that are not available in nature. Figure 1.1 shows the most well-known metamaterial implementation, the emblematical electromagnetic cloaking device [SCH 06a].

Figure 1.1 Two versions of an electromagnetic cloaking device using metamaterials designed by the D...