The Stripline Circulator


Book Description

Stripline circulator theory and applications from the world's foremost authority The stripline junction circulator is a unique three-port non-reciprocal microwave junction used to connect a single antenna to both a transmitter and a receiver. Its operation relies on the interaction between an electron spin in a suitably magnetized insulator with an alternating radio frequency magnetic field. In its simplest form, it consists of a microwave planar gyromagnetic resonator symmetrically coupled by three transmission lines. This book explores the magnetic interaction involved in the stripline circulator's operation, the nature of the microwave resonator shape, and the network problem that arises in coupling the microwave resonator to the microwave circuit. The stripline circulator is an important device met across a wide range of industries, including wireless, military, radar, and satellite communications. The book's design tables are a unique feature, offering valuable design support. Written by an international authority on non-reciprocal microwave circuits and devices, the book is organized into logical blocks of chapters that focus on specific effects and circuit aspects of the stripline circulator. Among the highlights of coverage are: Spatial shape demagnetizing factors of magnetic insulators Standing wave solutions of wye gyromagnetic planar resonators Lumped element circulators Negative permeability tracking and semi-tracking circulators Four-port single-junction circulators Fabrication of very weakly and weakly magnetized microstrip circulators The final chapter explores important and continuing discrepancies between theoretical models and actual practice. For designers building circulators, isolators, and phase shifters; researchers working on the limitation of ferrite devices; and graduate students intending to work in the field, Dr. Helszajn's insights and perspectives are invaluable.




Ferrites at Microwave Frequencies


Book Description

Includes a full mathematical treatment of the interaction of an electromagnetic wave with a gyromagnetic ferrite material.




Microwave Circulator Design, Second Edition


Book Description

Circulator design has advanced significantly since the first edition of this book was published 25 years ago. The objective of this second edition is to present theory, information, and design procedures that will enable microwave engineers and technicians to design and build circulators successfully. This resource contains a discussion of the various units used in the circulator design computations, as well as covers the theory of operation. This book presents numerous applications, giving microwave engineers new ideas about how to solve problems using circulators. Design examples are provided, which demonstrate how to apply the information to real-world design tasks.




Advances in Microwaves V6


Book Description

Advances in Microwaves, Volume 6 is a three-chapter text that explores the fundamental principles of precision coaxial connectors, traveling wave tubes, and junction circulators. Chapter 1 discusses the significant developments in the design, accuracy, and reference standard lines of precision coaxial connectors, with an emphasis on the application of the 7-mm and 14-mm precision coaxial connectors. Chapter 2 examines the stability of strongly modulated beams in a variety of focusing systems, such as uniform magnetic fields (Brillouin and near-Brillouin flow), linearly tapered magnetic fields, and periodic-permanent-magnet field systems. Chapter 3 deals with the theoretical aspects and characteristics of all types of junction circulators, with an emphasis on the lumped-element and the stripline circulator. Discussions on a theorem on passive three-port networks and star and delta networks are covered in the supplementary texts.




Modern Ferrites, Volume 2


Book Description

MODERN FERRITES, Volume 2 A robust exploration of the basic principles of ferrimagnetic and their applications In Modern Ferrites: Volume 2, renowned researcher and educator, Vincent G. Harris delivers a comprehensive overview of ferrimagnetic phenomena and discussions of select applications of modern ferrite materials in emerging technologies and applications. Volume 2 explores fundamental properties of ferrite systems, including their structure, chemistry, and magnetism, as well as practical applications, such as permanent magnets; inductors, inverters, and filters; and their use in emerging applications as metamaterials, multiferroics, and biomedical technologies. In addition to the properties of ferrites, the included resources explore the processing, structure, and property relationships in ferrites as nanoparticles, thin and thick films, compacts, and crystals. The authors discuss how these relationships are key to realizing practical device applications laying the foundation for next generation communications, radar, sensing, and biomedical technologies. This volume includes: A comprehensive review of ferrite discoveries and impacts upon ancient cultures, their scientific evolution, and societal benefits; Discussion of the origins of magnetism in ferrimagnetic oxides including superexchange theory, GKA-rules, and recent developments in density functional theory; In-depth examination of ferrite power conversion and conditioning components and their processing as low temperature co-fired ceramics; Ferrite-based electromagnetic interference suppression and electromagnetic absorption; Nonlinear microwave devices; multiferroic and emerging magnetoelectric devices; Biomedical applications of ferrite nanoparticles Perfect for RF engineers and magnetitians working in the fields of RF electronics, radar, communications, and spintronics as well as other emerging technologies. Modern Ferrites will earn a place on the bookshelves of engineers and scientists interested in the ever-expanding technologies reliant upon ferrite materials and new processing methodologies. Modern Ferrites Volume 1: Basic Principles, Processing and Properties is also available (ISBN: 9781118971468).




Advanced Computer Science and Information Technology


Book Description

This volume constitutes the refereed proceedings of the Third International Conference on Advanced Science and Technology, AST 2011, held in Seoul, South Korea, in September 2011. The 37 revised full papers presented in this volume were carefully reviewed and selected from numerous submissions. The papers feature ideas, problems and solutions relating to the multifaceted aspects of the Advanced Science and Technology, such as communication and networking; ubiquitous multimedia computing; security technology and information assurance; computer science, software engineering and applications thereof; bio-science and bio-technology; u- and e-service, science and technology; database theory and application; control and automation; signal processing, image processing and pattern recognition; as well as grid and distributed computing.




Microwave Physics and Techniques


Book Description

Microwave Physics and Techniques discusses the modelling and application of nonlinear microwave circuits and the problems of microwave electrodynamics and applications of magnetic and high Tc superconductor structures. Aspects of advanced methods for the structural investigation of materials and of MW remote sensing are also considered. The dual focus on both HTSC MW device physics and MW excitation in ferrites and magnetic films will foster the interaction of specialists in these different fields.




Microwave Engineering


Book Description

Pozar's new edition of Microwave Engineering includes more material on active circuits, noise, nonlinear effects, and wireless systems. Chapters on noise and nonlinear distortion, and active devices have been added along with the coverage of noise and more material on intermodulation distortion and related nonlinear effects. On active devices, there's more updated material on bipolar junction and field effect transistors. New and updated material on wireless communications systems, including link budget, link margin, digital modulation methods, and bit error rates is also part of the new edition. Other new material includes a section on transients on transmission lines, the theory of power waves, a discussion of higher order modes and frequency effects for microstrip line, and a discussion of how to determine unloaded.




Modeling and Design of Microwave Devices Based on Ferromagnetic Nanowires


Book Description

As wireless communication systems are flourishing and operating frequencies are progressively increasing, there exists nowadays a strong demand for RF devices at millimeter wavelengths. Nonmetallic ferromagnetic materials, also called ferrites, have found wide applications in RF technology as they possess the combined properties of a magnetic material and an electrical insulator. The remarkable flexibility in tailoring the magnetic properties, the very high resistivity, price and performance considerations make ferrites the first choice materials for microwave applications. However, the frequency range of operation, the bandwidth, and the aptitude to be integrated in MMICs should be improved. In this work, a new class of magnetic materials which could overcome the main disadvantages encountered when using ferrites in RF devices operating at millimeter wavelengths is studied. This material, called magnetic nanowired substrate (MNWS), is composed of an array of ferromagnetic nanowires embedded in a polymer substrate. First, the ferromagnetic nature of nanowires yields very high saturation magnetizations, thus operating frequencies higher than 40 GHz. Next, the nanometric wire diameter allows an easy penetration of electromagnetic waves inside the MNWS. Moreover, due to the high aspect ratio of nanowires the desired magnetic properties are obtained without an external magnetic field. This leads to a considerable potential increase of the compactness and ease of integration in MMICs. Various potential applications, such as filters and circulators, of this new material are presented.




Electromagnetic Materials and Devices


Book Description

Electromagnetic materials can be widely found in daily life, especially in electronic devices. The high-frequency properties (permittivity or permeability) of these materials strongly depend on structure, composition, shape, and orientation. Therefore, this book intends to present readers with advances not only in materials science (including metamaterials), but also in measurements and novel functional applications that demand the special properties of electromagnetic materials.