Читать книгу Introduction To Modern Planar Transmission Lines - Anand K. Verma - Страница 10

The planar transmission lines form the core of modern high‐frequency communication, computer, and other related technology. The subject has come up to the present level of maturity over the past three to four decades. The planar transmission lines are used not only as interconnects on the PCB board and IC chips; these are directly needed for the development of microwave and mm‐wave components in the form of microwave integrated circuits (MIC). The types of planar transmission lines, i.e. their physical structures and material medium, have been changing with the growth of technology in many other disciplines. Such efforts during recent years propelled the MIC to move in many exotic directions – MMIC, MEMS, LTCC, use of ferroelectrics, and high‐temperature superconductors, optically controlled microwave devices, nonlinear planar transmission lines, DGS, EBG, metamaterials, etc. The researchers with varying backgrounds have contributed much to research activities. Already the divergent planar technology has contributed significantly to the advancement of high‐frequency electronics and in the near future, more contribution will be made by it. The exotic planar transmission lines are not covered comprehensively in a single book. The present book is an attempt in this direction. The proposed book aims to provide a comprehensive discussion of planar transmission lines and their applications. It focuses on physical understanding, analytical approach, and circuit models for planar transmission lines and resonators in the complex environment.

The present book has evolved from the lecture notes, workshop, seminar presentation, and invited lectures delivered by the author at many universities and R&D centers. Some chapters were also initially written for the Ph.D. students to help them to understand the topics. Finally, it has evolved from notes prepared by the author as a scheme for the self‐study. The author started his academic career after 17 years of professional experience in the field of electrical engineering, broadcast transmitters, and satellite communication.

At present, the planar transmission lines are taught as part of the course on RF and microwave packaging, advanced electromagnetic field theory, and microwave design. It is also taught as an independent paper. However, a teacher has to consult divergent sources to prepare the lecture notes, as no single source at the teaching‐level is available. Moreover, the classroom teaching of the planar transmission lines is not as systematic as the classical metallic waveguide structures. It is due to the very nature of the subject itself. The available books are usually not classroom oriented. Usually, they can be grouped into two categories – 1. Design‐oriented books, 2. Monograph kind of books. Once we use the first category of books in the classroom, we end up writing only closed‐form expressions without any systematic derivation of the expressions. The systematic approach is important in the classroom environment. The second category of books is suitable for an experienced researcher or specialist. It is difficult to use them in the classroom. Thus, a teacher of this subject has to struggle between these two extremes to balance teaching throughout the semester. Finally, a teacher has to depend on personal experience and lecture notes.

There is a need to present, in one cover, the divergent topics of the planar transmission lines in a student‐friendly format. The researchers with varying backgrounds in physics, chemistry, engineering, and other fields have joined activities in the expanding area of the planar technology. The early researchers, R&D professionals in the industry, teachers, and students need a text that could be useful in faster acquisition of the physical modeling process and theoretical formulations used in the classical planar transmission lines. Similar treatment is also needed for the modern engineered EBG and metamaterial lines and surfaces.

Therefore, the real motivation for writing this intermediate‐level book is to fill the gap for a textbook on the planar transmission line that caters to the need for classroom teaching, early researchers with divergent backgrounds, and designers working in the microwave industry. The book is intended to help students both at the undergraduate and postgraduate levels. It also serves the purpose of a resource book for self‐study. The detailed derivations of results and physical modeling of the planar transmission lines are two basic concepts followed through the book. The present book is neither a design‐oriented book nor an advanced monograph. The book correlates the physical process with mathematical treatment. The advanced mathematical methods such as the conformal mapping method, variational method, and spectral domain method applied to planar lines are worked out in adequate details. The book further covers modern topics such as the DGS/EBG, metamaterial‐based planar transmission lines, and surfaces. The approach used in writing the book is perhaps less formal than most available texts. This approach is helpful for classroom teaching. It also assists the reader to follow the contemporary developments in planar technology.