Book Reviews

Advances in Microstrip and Printed Antennas

Edited by Kai Fong and Wai Chen ISBN 0-471-04421-0

Alan Searle
Senior Specialist, Antenna Systems Group
GEC-Marconi Research Centre

Microstrip and printed antennas find applications in an ever-widening array of civilian and government systems throughout the microwave spectrum. Their many attractive features, include being low profile, inexpensive to produce and mechanically robust The ability to easily integrate active devices with the antenna and is also an advantage. There has been considerable worldwide effort devoted to their development and the literature on the subject is therefore extensive. Since its publication in 1989, an excellent reference work has been the 'Handbook of Microstrip Antennas', edited by J.R.James and P.S.Hall In the 1990's, printed antennas have remained a rapidly advancing area of technology and there have been significant developments in conventional design approaches as well as in new research areas. 'Advances In Microstrip and Printed Antennas' is authored by an international collection of printed antenna specialists and aims to provide an updated view of the current state-of-the-at.

The first four chapters of the book deal with recent developments in conventional topics, including probe-fed and ape~ coupled antennas, microstrip arrays and circularly polarised systems. Consideration of probe-fed antennas is restricted to linearly polarised rectangular microstrip patches, but includes a range of multilayer and multipatch structures. Analysis of aperture coupled antennas is also extended to multilayer geometries in addition to infinite arrays. There is a lot of mathematical detail in these early chapters which will be of value to the antenna researcher. The treatment of microstrip arrays is rather brief, but reviews analysis techniques and practical design approaches. A recently developed array configuration, the microstrip reflectarray is highlighted. Chapter 4 covers dual and circularly polarised microstrip antennas and presents an overview of recent innovations in this diverse field.

The remaining chapters address relatively new topics. The first four of these concern microstrip systems and cover computer aided design (CAD), multifunction, superconducting and active antennas. The treatment of CAD is limited to rectangular patch antennas but provides useful formulae for key antenna characteristics. While multifunction antennas are not a new concept, recent design trends are highlighted and related to intrinsic design features of printed antennas. The topic of superconducting microstrip antennas is covered in a chapter which introduces the benefits, and problems, associated with high temperature superconductors. Similarly, the concept and implementation of active integrated antennas is reviewed.

The final three chapters of the book cover non-microstrip printed antennas in the form of tapered slots and dielectric resonators, plus a timely presentation of efficient modelling using the finite difference time domain (FDTD) technique. Typical tapered slot designs are reviewed and two relatively new variants are discussed. Detailed theoretical and experimental results of recent developments in dielectric resonator antennas are presented. Principles of the FDTD method of analysis are outlined and illustrated with several examples.

At over 600 pages, this is a comprehensive book covering many dynamic areas of modern printed antenna design. Although the page limit means that some topics are necessarily treated in a summary fashion, each chapter is supported by an extensive list of references. The content is generally balanced between fundamental theoretical treatments and examples of practical applications. Both antenna researchers and practising engineers will therefore find much useful information in this well presented text. Enter Enquiry No. 47

Introduction To Classical and Quantum Harmonic Oscillators

It is physically impossible to shake a stick without becoming consciously aware, or indeed unconsciously aware, of the all pervasive presence of harmonic oscillators. In this fascinating treatment of the subject the author Sylvan C. Bloch, a professor at the University of South Florida, displays an exceptional understanding and a singular insight into the universal implications of these devices both from considerations of their obvious scientific value and as objects of beauty.

This publication reaches far beyond being a simple design aid, it is in itself an experience encouraging a thought process extending and stimulating the imagination thus providing a vehicle for greater scientific understanding.

The book comes complete with software which will run on a number of standard spreadsheets, Microsoft Excel, Quattro Pro, and Lotus 1-2-3 for example. This enables the user to interface with the subject, to question the consequence of certain variables and conditions, and to examine concepts of deep complexity receiving immediate results without being burdened with a mass of calculations.

My own reaction is, had this treatise been available during my student days it would probably have made me a better engineer. Thoroughly recommended as stimulating reading for any red blooded professional, engineer, or engineering student of electronics, electrical, or mechanical engineering.

Control and Measurement of Unintentional Electromagnetic Radiation

Dr W. Scott Bennett, the author of the above book, is a lecturer and independent consultant in electronics, he has thirty years experience in digital design and electromagnetic compatability with a number of leading companies in the field including Hewlett-Packard, Burroughs, and General Electric. The book published 1997 by John Wiley & Sons Inc. is one of a leading series of publications in science and engineering released under the Wiley Interscience banner.

Given the limited availability of any formal degree or qualification in EMC engineering, the practising technician or electrical/electronic design engineer has found himself to be dependant upon a diversity of sources for useful and relevant subject information. Many of those sources themselves have been produced by Instrument Companies, Test Houses and suppliers of other EMC products or services and have, for the greater part, been written with a strong commercial bias.

In the above endeavour the author examines the problem, dissects it into manageable and understandable components, and discusses means by which the designer can avoid the numerous incompatibility traps. Embracing first the causes and then investigating the means by which electromagnetic radiations may be minimised. The various aspects of control and containment, and the subsequent measurement requirements are considered. Whilst essentially theoretical, this work remains lucid without burdening the reader with a package of unnecessarily complex mathematics. The appendix excepted, nothing more than a good understanding of algebra and trigonometry are expected for a full appreciation of it's content.

The subject is first approached from a discussion of the theory of radiation and consequent radiation patterns, this, on the reasonable premise that to solve the problem it's cause and effect needs first to be appreciated. This theoretical posture is then adapted to identify and characterise some critical sources of radiation and to suggest some techniques for the control and minimisation of such. Consideration is given to parameters such as impedance, voltage amplitude and waveforms, including the equivalent frequency domain description, circuit currents and the geometry of circuit current paths, as well as the principles and implications of radiation containment and cancellation of potential sources of radiation.

The requirements for a test environment in which to make meaningful measurements of radiation are also explored. Consideration is given to calibration and validation of antennas together with the characteristics to be considered in the construction of a test site.

This book would constitute a useful source of information and reference for designers, engineers, electronic quality managers, and any consulting bodies concerned with the compatible design and manufacture of electronic or electrical systems.