Design of Ultra Wideband Antenna Matching Networks
Design of Ultra Wideband Antenna Matching Networks Via Simplified Real Frequency Technique 123
Dr. College of Engineering Department of Electrical-Electronics Engineering Istanbul University 34320, Avcilar, Istanbul Turkey sbyarman@gmail.com ISBN: 978-1-4020-8417-1 e-isbn: 978-1-4020-8418-8 Library of Congress Control Number: 2008926115 c 2008 Springer Science+Business Media B.V. No part of this work may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording or otherwise, without written permission from the Publisher, with the exception of any material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Printed on acid-free paper 9 8 7 6 5 4 3 2 1 springer.com
This book is dedicated to my wife Sema for her endless patience and love
Preface Antennas, antenna matching networks (or equalizers), antenna switches and phase shifters of antenna arrays are the most critical components of ultra wideband communications systems. As a whole, they constitute, what we call is the antenna system. It is obvious that these critical components are placed in the front-ends of the communication systems. In other words, transmitters and receivers start with antenna systems. If the antenna system is wideband, then the wireless set up may have a strong chance to be wideband. Otherwise, no matter how good is the rest of the communication system, the system s bandwidth is bounded by the antenna gears. Commercially, one can find variety of antenna design handbooks and/or Computer Aided Design (CAD) tools to construct antennas. On the other hand, as far as design of wideband practical matching networks is concerned, there is not much available for the design engineers on the market place. The topic is hot but difficult to comprehend. Over the last 30 years, the design methods known as the real frequency techniques (RFT), which was initiated by Prof. H.J. Carlin of Cornell University, provided excellent solutions to construct power transfer networks for many applications. Furthermore, the Simplified Real Frequency Technique (SRFT) has been verified as the most suitable one to design matching networks and microwave amplifiers for antennas. Therefore, this book is solely devoted to design ultra wideband practical antenna matching networks employing SRFT. We tried to make the topic as simple as possible for the designers by providing ready to use software (S/W) tools developed on (SRFT). Once the measured data is plugged into SRFT design tool, the complete lossless matching network is obtained at the output. The book starts with the historical review of the real frequency techniques (Chapter 1), electromagnetic field theory and antenna performance related definitions (Chapter 2). Then, major issues of antennas employed in modern cellular communication systems are covered in Chapters 3 6. Thus, the first 6 chapters of the book are prepared to orient the new comers exposed to wireless communication engineering. We recommend theses chapters to be covered in junior and senior classes in Communication Engineering Departments. Chapter 7 fully covers the scattering parameters from the design perspective. In this chapter, emphasis is given to lossless two-ports which is essential to construct matching networks for antennas. vii
viii Preface In Chapter 8, basic concepts and analytic theory of broadband matching is introduced. Several practical examples are presented. In Chapter 9, Simplified Real Frequency Technique (SRFT) to design ultra wideband Matching Networks is introduced. In this chapter, the reader is guided with several examples to develop her or his own design tool employing SRFT on the MatLab environment. Eventually, a home made design tool is provided by us to facilitate the work of the reader. This home made tool is developed on MatLab utilizing Levenberg-Marquard non-linear optimization algorithm. Chapter 10 is devoted to real life problems to construct antenna matching networks. The first problem is to design an ultra-wideband matching networks for a short monopole antenna which may be utilized for military and commercial purposes. In the second problem, we design a multi-band matching network for a PIFA antenna employed for the cellular bands of GSM 900/1800 and CDMA 1900. As it is well known, nonlinear optimization requires excellent initials. Therefore, in Chapter 11, we introduce initialization techniques for SRFT design algorithm. Once the SRFT design is completed, it may be necessary to retrofit the original design to production technology. In this regards, commercially available S/W tools such as ADS and AWR can be utilized. Therefore, in Chapter 12 and 13 basic ingredients of ADS and AWR are covered and examples are presented. From the graduate education and research point of view, Chapters 7 11 can be used for masters and Ph.D programs. Furthermore, we strongly believe that the book will be useful for research managers and design engineers employed by commercial wireless communication companies as well as government and military agencies. Vanikoy, Istanbul, Turkey
Acknowledgments I should emphasize with great pleasure that it would not be possible to put this book without mental guidance of Prof. H.J. Carlin of Cornell University throughout my professional life. He deserves a big applause for initiating the real frequency technique which facilitates design and implementation process of any kind of matching network including antenna systems. Sincere gratitude are extended to Prof. Y. Tokad of National Research Center (or in short TUBITAK) of Turkey, who passed-away in 2001 with rigor, Prof. D.C. Youla of New York Polytechnique Institute, Prof. P.P. Civalleri of Torino University, Italy, Prof. A. Fettweis of Ruhr University, Germany, Prof. E. Tutuncuoglu of Istanbul University and Prof. N. Fujii of Tokyo Institute of Technology. They all provided with me their immense support furnished with outstanding research ideas and environments. I would like to thank to my former Ph.D students Dr. Metin Sengul of Kadir Has University and Dr. Ali Kilinc of Elma Corp. who partially help me with SRFT S/W development especially with the synthesis of driving point functions and also with the figures of the book. It must be acknowledged that recent SRFT practical antenna matching networks were designed and physically built within the European Union Project NEWCOM (Department 3 of Network of Excellence for Wireless Communication Contract No IST NoE 507325.) under guidance of group leaders Prof. M. Hein of Ilmenau Technical University of Germany, Prof. A. Rydberg of Uppsala University, Sweden. Vanikoy, Istanbul, Turkey ix
Contents 1 Real Frequency Techniques... 1 2 Antenna Fundamentals... 9 Bhaskar Gupta 3 Antennas for Mobile Wireless Communication... 39 Peter Lindberg 4 Challenges in Mobile Phone Antenna Development... 45 Peter Lindberg 5 Design Techniques for Internal Terminal Antennas... 67 Peter Lindberg 6 Terminal Antenna Measurements... 93 Peter Lindberg 7 Description of Lossless Two Ports in Terms of Scattering Parameters...101 8 Analytic Approaches to Antenna Matching Problems...139 9 Simplified Real Frequency Technique...183 10 Applications...225 11 Initialization of Simplified Real Frequency Technique...257 xi
xii Contents 12 Analysis and Optimization of Matching Networks-I...281 Metin Sengul 13 Analysis and Optimization of Matching Networks-II...293 Metin Sengul Index...305
Contributors College of Engineering, Department of Electrical-Electronics Engineering, Istanbul University, 34320, Avcilar, Istanbul, Turkey, sbyarman@gmail.com Bhaskar Gupta Jadavpur University, India, bgupta@etce.jdvu.ac.in Peter Lindberg Laird Technologies AB, Mobile Antenna Systems, Research Department, Isafjordsgatan 5, 164 22 Kista, Sweden, peter.lindberg@lairdtech.com Metin Sengul Kadir Has University, Engineering Faculty Electronics Engineering Department, 34083, Cibali-Fatih, İstanbul, Turkey, mtnsngl@gmail.com xiii