- Email: [email protected]
Antennas and waves: a modern approach
Book Reviews to unresolved problems and puzzles, and thus in a sense foretells where the action probably will be. The book should stimulate enthusiasm for the subject not only among graduate and undergraduate students of physics, but also in those who are concerned with problems of the solid earth. LOUIS B. SLICHTER Institute of CTeophysics and Planetary Physics University of California, Los Angeles ANTENNAS AND WAVES: A MODERN APPROACH, by Ronold W. P. King and Charles Harrison, Jr. 778 pages, diegrams, 7 x 10 in. Cambridge, Mass., The MIT Press, 1970. Price, $15.00.
The problem of electromagnetic radistion from electric conductors and arrays of such conductors is treated in this volume. It represents the work and thinking of Professor King of Harvard University and his colleagues and students, for the past several decades. Included among the types of antennas considered are conducting cylinders and loops, dipoles, transmission line antennas, inverted L's, T's, folded antennas and slot antennas. Many of these topics are obviously not novel, and historically there has been a diversity of methods used in treating them. These treatments vary all the way in depth from a handbook approach, through an intermediate level, in which the simplest mathematical approach that yields useful and reliable results is considered adequate, to the very formal and analytical approach found in the present work. In any event, what is required is information on the impedance, the, directional characteristics, the resonant frequency and band width, and ohmic compared to radiation losses of any antenna or antenna array. This text will prove too difficult for those without extensive mathematical preparation. The use of the subtitle-“A Modern Approach”-is justified by the extension of classical antenna theory to include antennas immersed in a dissipative medium or in a plasma characterized by
484
its own resonances and loss mechanisms. The chapter on the behavior of an ant&a in ionized media and plasmas is well done. In a work of this sort, it is inevitable that some topics are not treated, depending on the objectives of the authors. This is not a book on wave propagation. There is no mention of helical antennas even though these have found many applications. Horns and apertures are not treated, except for the slot antennas. The somewhat sophisticated methods used in interconnecting antennas, for example those on a tumbling satellite, are not treated. Appendix 3 gives tables of admittance, impedance, effective length and directivity of center-driven cylindrical antennas, while Appendix 4 gives corresponding information for electrically long antennas and together these occupy some 30 pages. The book is not intended for the beginner but will prove informative to workers concerned with a wide variety of antennas. W. D. .HERSHBER~ER Electrical Sciences and Engineering Department Univewity of California, Los Angeles GRAPH THEORY, by Frank Harary. 274 pages, diagrams, 6 x 9 in. Reading, 1969. Price, Mass., Addison-Wesley, $12.50. A reasonably comprehensive account of the theory of graphs is presented here. The writing is concise. This is achieved with the aid of a formidable number of definitions and by omitting most of the proofs that are difficult and long. Thus, these are also the drawbacks of an otherwise excellent book. The book has sixteen short chapters. First a brief description of the background and history of graph theory is given, and provides a motivation for the study of subsequent chapters. This is followed by the basic concepts and terminology of graph theory. The remaining fourteen chapters are devoted to the discussions of: blocks, trees, connectivity, partitions, traversability, line graphs, factorization, coverings, planarity, colorability, matrices, groups, enumeration and digraphs, presented in that order. With the exception
Journal of TheFranklinInstitute
The problem of electromagnetic radistion from electric conductors and arrays of such conductors is treated in this volume. It represents the work and thinking of Professor King of Harvard University and his colleagues and students, for the past several decades. Included among the types of antennas considered are conducting cylinders and loops, dipoles, transmission line antennas, inverted L's, T's, folded antennas and slot antennas. Many of these topics are obviously not novel, and historically there has been a diversity of methods used in treating them. These treatments vary all the way in depth from a handbook approach, through an intermediate level, in which the simplest mathematical approach that yields useful and reliable results is considered adequate, to the very formal and analytical approach found in the present work. In any event, what is required is information on the impedance, the, directional characteristics, the resonant frequency and band width, and ohmic compared to radiation losses of any antenna or antenna array. This text will prove too difficult for those without extensive mathematical preparation. The use of the subtitle-“A Modern Approach”-is justified by the extension of classical antenna theory to include antennas immersed in a dissipative medium or in a plasma characterized by
484
its own resonances and loss mechanisms. The chapter on the behavior of an ant&a in ionized media and plasmas is well done. In a work of this sort, it is inevitable that some topics are not treated, depending on the objectives of the authors. This is not a book on wave propagation. There is no mention of helical antennas even though these have found many applications. Horns and apertures are not treated, except for the slot antennas. The somewhat sophisticated methods used in interconnecting antennas, for example those on a tumbling satellite, are not treated. Appendix 3 gives tables of admittance, impedance, effective length and directivity of center-driven cylindrical antennas, while Appendix 4 gives corresponding information for electrically long antennas and together these occupy some 30 pages. The book is not intended for the beginner but will prove informative to workers concerned with a wide variety of antennas. W. D. .HERSHBER~ER Electrical Sciences and Engineering Department Univewity of California, Los Angeles GRAPH THEORY, by Frank Harary. 274 pages, diagrams, 6 x 9 in. Reading, 1969. Price, Mass., Addison-Wesley, $12.50. A reasonably comprehensive account of the theory of graphs is presented here. The writing is concise. This is achieved with the aid of a formidable number of definitions and by omitting most of the proofs that are difficult and long. Thus, these are also the drawbacks of an otherwise excellent book. The book has sixteen short chapters. First a brief description of the background and history of graph theory is given, and provides a motivation for the study of subsequent chapters. This is followed by the basic concepts and terminology of graph theory. The remaining fourteen chapters are devoted to the discussions of: blocks, trees, connectivity, partitions, traversability, line graphs, factorization, coverings, planarity, colorability, matrices, groups, enumeration and digraphs, presented in that order. With the exception
Journal of TheFranklinInstitute