Artificial Transmission Lines for RF and Microwave Applications (eBook)

Ferran Mart n (Autor)

eBook Download: EPUB

2015
Wiley (Verlag)
978-1-119-05837-3 (ISBN)

Infos

This book presents and discusses alternatives to ordinary transmission lines for the design and implementation of advanced RF/microwave components in planar technology.
This book is devoted to the analysis, study and applications of artificial transmission lines mostly implemented by means of a host line conveniently modified (e.g., with modulation of transverse dimensions, with etched patterns in the metallic layers, etc.) or with reactive loading, in order to achieve novel device functionalities, superior performance, and/or reduced size.
The author begins with an introductory chapter dedicated to the fundamentals of planar transmission lines. Chapter 2 is focused on artificial transmission lines based on periodic structures (including non-uniform transmission lines and reactively-loaded lines), and provides a comprehensive analysis of the coupled mode theory. Chapters 3 and 4 are dedicated to artificial transmission lines inspired by metamaterials, or based on metamaterial concepts. These chapters include the main practical implementations of such lines and their circuit models, and a wide overview of their RF/microwave applications (including passive and active circuits and antennas). Chapter 5 focuses on reconfigurable devices based on tunable artificial lines, and on non-linear transmission lines. The chapter also introduces several materials and components to achieve tuning, including diode varactors, RF-MEMS, ferroelectrics, and liquid crystals. Finally, Chapter 6 covers other advanced transmission lines and wave guiding structures, such as electroinductive-/magnetoinductive-wave lines, common-mode suppressed balanced lines, lattice-network artificial lines, and substrate integrated waveguides.
Artificial Transmission Lines for RF and Microwave Applications provides an in-depth analysis and discussion of artificial transmission lines, including design guidelines that can be useful to researchers, engineers and students.

Ferran Martín is a Full Professor of Electronics in the Departament d'Enginyeria Electrònica at the Universitat Autònoma de Barcelona (UAB) in Spain. He is the head of the Microwave Engineering, Metamaterials and Antennas Group (GEMMA) at UAB and the director of CIMITEC, a research Center on Metamaterials. Dr. Martín has generated over 450 book chapters, journal papers and conference contributions (most of them on topics related to the book), and has supervised 14 PhDs. He holds one of the Parc de Recerca UAB/Santander Technology Transfer Chairs at UAB, and has been the recipient of the Duran Farell Prize (2006) and the ICREA Academia Award (2008 and 2013). He is IEEE Fellow since 2012.

Textauszug

PREFACE

Transmission lines and waveguides are essential components in radiofrequency (RF) and microwave engineering for the guided transmission of electromagnetic (EM) energy (power and information signals) between two points. Moreover, transmission lines and waveguides are key building blocks for the implementation of passive and active RF/microwave devices of interest in wireless communications (filters, diplexers, splitters, couplers, amplifiers, oscillators, mixers, etc.). In planar technology, low-cost devices can be fabricated by etching patterns (a set of transmission lines and stubs providing certain functionality) in a printed circuit board (PCB), avoiding the use of lumped components, such as capacitors, inductors, or resonators. Transmission line-based circuits are usually designated as distributed circuits, since transmission lines can be described by a network of distributed parameters. In certain designs (e.g., amplifiers and mixers), it is necessary to combine distributed and lumped active elements, such as diodes or transistors. Nevertheless, the main relevant aspect of distributed components is their capability to mimic lumped-reactive elements or a combination of them (e.g., resonators or even more complex reactive circuits). It is thus possible to design fully planar functional devices on the basis of the distributed approach, or to minimize the number of lumped elements (unavoidable in certain components, e.g., active circuits) in the designs.

Distributed circuits have two main drawbacks: (1) their dimensions scale with frequency, and (2) transmission lines exhibit very limited design flexibility. Typically, the required transmission lines in the designs have a length of the order of the wavelength, which means that dimensions may be too extreme if the operating frequencies are moderate or low. Concerning the second aspect, distributed circuits are designed by means of transmission lines with certain phase (at the operating frequency) and characteristic impedance. The phase varies linearly with the length of the line and frequency (to a first-order approximation transmission lines are dispersionless). Therefore, the functionality of distributed circuits is limited to a certain band; namely, the required nominal phase is lost if frequency deviates from the operating value, which means that distributed circuits are bandwidth limited by nature.

The limitations of ordinary transmission lines as building blocks for device design are in part originated from the fact that these lines exhibit a limited number of free parameters for design purposes (by excluding losses, ordinary lines are described by a distributed network with two reactive elements in the unit cell). However, by truncating the uniformity (in the longitudinal direction), by etching patterns in the ground plane, by loading the line with reactive elements, or by using a combination of these (or other) strategies to increase the degrees of freedom of the lines, many possibilities to reduce device size, to improve performance, or to achieve novel functionalities, are open. This book has been mainly conceived to introduce and study alternatives to ordinary lines for the design and implementation of RF/microwave components with superior characteristics in the above cited aspects. We refer to these lines as artificial transmission lines, and the term is as wide as the number of strategies that one can envision to improve the size, performance, or functionality of ordinary lines. The book is devoted to the analysis, study, and applications of artificial lines mostly implemented by means of a planar transmission line (host line) conveniently modified (e.g., with modulation of transverse dimensions, with etched patterns in the metallic layers, and with reactive loading), in order to achieve certain functionality, superior performance, or reduced size. Nevertheless, it will be shown that in certain artificial waveguiding structures, such as electroinductive and magnetoinductive delay lines, the host line is not present. Waveguide-based components are not included in this book, entirely focused on artificial transmission lines in planar technology. Obviously, it is not possible to cover all the material available in the literature, related to the topic of artificial transmission lines, in a single book. Necessarily, the contents of this book are influenced by the personal experience and background of the author. However, many RF/microwave devices and applications of artificial transmission lines reported by other researchers are included in this book, or properly referenced.

The book is devoted to readers that are already familiar with RF/microwave engineering. The aim of writing this book has been to provide an up-to-date state of the art in artificial transmission lines, and an in-depth analysis and study of those aspects, structures, devices, and circuits that are more relevant (according to the criterion of the author) for RF/microwave engineering, including design guidelines that can be useful to researchers, engineers, or students involved in the topics covered by this book. Nevertheless, Chapter 1 is dedicated to the fundamentals of planar transmission lines for coherence and completeness, since most of the concepts of this chapter are used in the subsequent chapters, and are fundamental to understand the principles and ideas behind the design and applications of artificial transmission lines.

Chapter 2 is focused on artificial transmission lines based on periodic structures, where periodicity plays a fundamental role and is responsible for the presence of band gaps in the transmission spectrum of these lines. The Floquet analysis (leading to the concept of space harmonics), complemented by the coupled mode theory (from which useful expressions for the design of periodic artificial lines are derived), and the transfer matrix method (useful to obtain the dispersion relation of the fundamental space harmonic), are included in the chapter. The last part is devoted to the applications, which have been divided into those of periodic nonuniform transmission lines (e.g., harmonic and spurious suppression), and those of reactively loaded lines, where not only the reflection properties of periodic structures but also the inherent slow-wave effect associated to reactive loading, are exploited.

Chapters 3 and 4 are dedicated to artificial transmission lines inspired by metamaterials, or based on metamaterial concepts. The importance of these artificial lines in this book has forced the author to separate the fundamentals/theory and applications into different chapters in order to avoid an excessive chapter length. Thus, Chapter 3 is focused on the theory, circuit models, and main implementations of metamaterial transmission lines, whereas Chapter 4 deals with the applications. Many applications of metamaterial transmission lines are based on the superior controllability of the characteristic impedance and dispersion of these lines, as compared to ordinary lines, related to the presence of reactive elements loading the line. Indeed, metamaterial transmission lines have opened a new way of “thinking” in the design of microwave components, where tailoring the dispersion diagram, and not only the characteristic impedance, is the key aspect (we may accept that metamaterial transmission lines have given rise to microwave circuit design on the basis of impedance and dispersion engineering). The further controllability of the relevant line parameters (phase constant and characteristic impedance) in metamaterial transmission lines, as compared to ordinary lines, has a clear parallelism with the further controllability of the constitutive parameters (permittivity and permeability) in effective media metamaterials (periodic artificial structures exhibiting controllable EM properties, different from those of the materials which they are made). Indeed, we can define an effective permittivity and permeability in metamaterial transmission lines despite that these lines are one-dimensional structures, and we can design the lines in order to support backward (or left-handed) wave propagation (as occurs in metamaterials with simultaneous negative effective permittivity and permeability). However, whereas in effective media metamaterials periodicity and homogeneity (satisfied if the period is much smaller than the wavelength) are necessary conditions to properly define an effective permeability and permittivity, periodicity, and homogeneity are not requirements for impedance and dispersion engineering with metamaterial transmission lines.

The former metamaterial transmission lines were implemented by loading a host line with series capacitors and shunt inductors (CL-loaded approach), or by loading the host lines with electrically small resonators, formerly used for the implementation of bulk effective media metamaterials (metamaterial resonators). This latter approach has been called resonant-type approach. Both approaches are included in this book (and many other latter developments), but special emphasis is put on the resonant-type approach. Moreover, in Chapter 4 there are several applications where, rather than the controllability of the impedance and dispersion of the artificial lines, the working principle is the resonance of a transmission line (host line) loaded with metamaterial resonators (these lines are designated as transmission lines with metamaterial loading in Chapter 4). Since metamaterial transmission lines are inspired by metamaterials, an introduction to these artificial media and the former implementation are included in Chapter 3....

Produkt-Details

• Erscheint lt. Verlag: 1.7.2015
• Reihe/Serie: Wiley Series in Microwave and Optical Engineering
• Reihe/Serie: Wiley Series in Microwave and Optical Engineering
• Reihe/Serie: Wiley Series in Microwave and Optical Engineering
• Sprache: englisch
• Themenwelt: Technik ► Elektrotechnik / Energietechnik
• Themenwelt: Technik ► Nachrichtentechnik
• Schlagworte: Antennas & Propagation • artificial transmission lines • canonical models of metamaterial • common-mode suspension • Coupled Mode Theory • CRLH transmission lines • Distributed Circuits • effective material metamaterials • Electrical & Electronics Engineering • electrically small resonators • electroinductive-wave (EIW) delay lines • Electromagnetic theory • Elektromagnetismus • Elektrotechnik u. Elektronik • floquet analysis • loaded (terminated) transmission lines • Lossy transmission lines • lumped element equivalent circuit models • Magnetoinductive-wave (MIW) delay lines • Metamaterial Transmission Lines • Mikrowellen- u. Hochfrequenztechnik u. Theorie • Nonlinear transmission lines (NLTLs) • periodic structures • Planar transmission lines • RF / Microwave Theory & Techniques • Sende- u. Empfangseinrichtungen • Substrate integrated waveguides (SIW) • Transfer Matrix Method • transmission line parameters • tunable devices • wideband artificial lines
• ISBN-10: 1-119-05837-6 / 1119058376
• ISBN-13: 978-1-119-05837-3 / 9781119058373