Microwaves Millimeter Wave And Terahertz Liquid Crystals

Describes the theory, modeling, and design of tunable mm-wave circuits and systems using CMOS, RF MEMS, and microwave liquid crystals.

This book presents original findings on tunable microwave metamaterial structures, and describes the theoretical and practical issues involved in the design of metamaterial devices. Special emphasis is given to tunable elements and their advantages in terms of feeding network simplification. Different biasing schemes and feeding network topologies are presented, together with extensive prototype measurements and simulations. The book describes a novel, unique solution for beam steering and beam forming applications, and thus paves the way for the diffusion of new agile communication system components. At the same time, it provides readers with an outstanding and timely review of wave propagation in periodic structures, tunability of metamaterials and the technological constraints that need to be considered in the design of reconfigurable microwave components.

Key advances in Semiconductor Terahertz (THz) Technology now promises important new applications enabling scientists and engineers to overcome the challenges of accessing the so-called "terahertz gap". This pioneering reference explains the fundamental methods and surveys innovative techniques in the generation, detection and processing of THz waves with solid-state devices, as well as illustrating their potential applications in security and telecommunications, among other fields. With contributions from leading experts, Semiconductor Terahertz Technology: Devices and Systems at Room Temperature Operation comprehensively and systematically covers semiconductor-based room temperature operating sources such as photomixers, THz antennas, radiation concepts and THz propagation as well as room-temperature operating THz detectors. The second part of the book focuses on applications such as the latest photonic and electronic THz systems as well as emerging THz technologies including: whispering gallery resonators, liquid crystals, metamaterials and graphene-based devices. This book will provide support for practicing researchers and professionals and will be an indispensable reference to graduate students in the field of THz technology. Key features: Includes crucial theoretical background sections to photomixers, photoconductive switches and electronic THz generation & detection. Provides an extensive overview of semiconductor-based THz sources and applications. Discusses vital technologies for affordable THz applications. Supports teaching and studying increasingly popular courses on semiconductor THz technology.

The International Conference of Electronic Engineering and Information Science 2015 (ICEEIS 2015) was held on January 17-18, 2015, Harbin, China. This proceedings volume assembles papers from various researchers, engineers and educators engaged in the fields of electronic engineering and information science.The papers in this proceedings

Written in a clear and concise manner, this book presents readers with an in-depth discussion of the 5G technologies that will help move society beyond its current capabilities. It perfectly illustrates how the technology itself will benefit both individual consumers and industry as the world heads towards a more connected state of being. Every technological application presented is modeled in a schematic diagram and is considered in depth through mathematical analysis and performance assessment. Furthermore, published simulation data and measurements are checked. Each chapter of 5G Physical Layer Technologies contains texts, mathematical analysis, and applications supported by figures, graphs, data tables, appendices, and a list of up to date references, along with an executive summary of the key issues. Topics covered include: the evolution of wireless communications; full duplex communications and full dimension MIMO technologies; network virtualization and wireless energy harvesting; Internet of Things and smart cities; and millimeter wave massive MIMO technology. Additional chapters look at millimeter wave propagation losses caused by atmospheric gases, rain, snow, building materials and vegetation; wireless channel modeling and array mutual coupling; massive array configurations and 3D channel modeling; massive MIMO channel estimation schemes and channel reciprocity; 3D beamforming technologies; and linear precoding strategies for multiuser massive MIMO systems. Other features include: In depth coverage of a hot topic soon to become the backbone of IoT connecting devices, machines, and vehicles Addresses the need for green communications for the 21st century Provides a comprehensive support for the advanced mathematics exploited in the book by including appendices and worked examples Contributions from the EU research programmes, the International telecommunications companies, and the International standards institutions (ITU; 3GPP; ETSI) are covered in depth Includes numerous tables and illustrations to aid the reader Fills the gap in the current literature where technologies are not explained in depth or omitted altogether 5G Physical Layer Technologies is an essential resource for undergraduate and postgraduate courses on wireless communications and technology. It is also an excellent source of information for design engineers, research and development engineers, the private-public research community, university research academics, undergraduate and postgraduate students, technical managers, service providers, and all professionals involved in the communications and technology industry.

The Special Issue “Liquid Crystal Optical Devices” discusses recent developments in the rapidly advancing subject of liquid crystals (LCs). The book is composed of several contributions from researchers in the field of liquid crystals that deal with the broadly with aspects of optical devices ranging from a theoretical viewpoints to practical implications of the properties of LCs. This is the first Special Issue devoted solely to recent advances in the rapidly expanding subject of LCs, a unique class of substances that combines both ordered structures with quasi-liquid-like properties. This Special Issue offers a broad perspective of the present state of the art in design and an up-to-date account of the most recent advances and progress in the field of LCs, providing thorough coverage of the demonstrated optical devices and the comprehensive analysis needed by professionals and engineers in the field of LC. The material is carefully structured, providing readers with a solid foundation of the principles, capabilities, use, and limitations of LC optical devices. In addition, this book covers the principles, recent advances and future developments of liquid crystal beam steering devices as well as recent advances in adaptive liquid crystal lenses.

Antennas represent a critical technology in any of these wireless systems. Not only do they directly affect the received power of the system, they are also typically the largest and most visible part. Recently, the need for low-cost, low-profile, and lightweight antenna in the frequency range of the microwave/millimeter wave/THz band has regained momentum. "Basic Principles of Fresnel Antenna Arrays" provides us a with the basics of the various Fresnel Antenna approaches, in order to achieve low-cost, low-profile, and lightweight antenna in the microwave/millimeter wave band. A potential solution of the antenna problem lies in using lens technology in an array. The Fresnel zone plate lens (FZPL) antenna is in particular an interesting candidate for the array element. The limiting focusing properties of FZPL including subwave length focus are described in detail. The book further presents a novel hexagonal FZPL antenna which can be more effectively packed in an array due to its shape. Before considering the hexagonal FZPL antenna in an array, the authors investigate two ideas, described as methods to potentially improve the radiation characteristics. The first idea is to change the reference phase of the Fresnel zone radii - a novel free parameter in the usual design of zone plate’s lenses and antennas. To further improve the radiation characteristics of the hexagonal FZPL antenna, a technique involving Fresnel zone rotation is investigated. The book is of interest for designers of optical systems because, taking scaling effects into account, the characteristics of diffractive quasioptical elements are valid for diffractive focusing elements of integrated optics.