Book reviewHigh-frequency amplifiersRalph S. CarsonJ. Wiley & Son, 1982, 2ndedn., 291 pp., £23.00ISBN: 0-471-86832-9

This book consists of seven chapters—transistor par-ameters and stability, amplifier design principles, the SmithChart and matching networks, amplifier design, bias stabil-isation, scattering parameters, and design using scatteringparameters, followed by two appendixes. There is a briefbibliography, citing books and papers, many of which arefrom the 1950s and 1960s.

The author intends this work to be used as a text for aone halfyear (semester) course for final-year under-graduates, and for postgraduates in electrical engineering,as well as an introductory review and source of informa-tion for engineers and managers.

Many worked examples are included, but these aremainly plugging numbers into formulas and bear littlerelation to practical situations. Each chapter ends with aselection of problems to which the same comments apply.

Taking the author's chapter headings in turn, the limi-tations implied by treating transistors as 2-ports are neverstated, despite the fact that they are 3- or 4-terminaldevices, none of which are at AC ground in many circuits,especially at high frequencies. Since h- or z-parameters arevery difficult to measure at such frequencies and much lessconvenient for commonly available CAD programs, onequestions why they are included at all.

The author states (correctly) that there is considerableconfusion about 2-port s-parameter conditions for inherent

stability, but he fails to clarify it or to cite recent definitivepapers. He also fails to point out that the conditions applyonly to 2-ports with arbitrary passive terminations.Neither the restricted range of passive terminations whichoccur in many practical situations, nor other more generalmethods of assessing stability, such as return ratios, arementioned. The use of negative resistance to denote a1-port impedance with phase angle exceeding 90° in eitherdirection is unfortunate, and causes confusion with devicesexhibiting negative resistance over limited ranges of biasconditions (e.g. tunnel diode) and a limited range of fre-quencies (transit-time devices).

The absence of output characteristics, ^-parameters or5-parameters from manufacturers' data sheets or technicaljournals emphasises the gap between text and practice.Other serious omissions are field-effect transistors, espe-cially GaAs MESFETs, and any references to computer-aided analysis and design of amplifiers. On the other hand,the inclusion of 40 pages (out of 268) devoted to bias sta-bilisation of bipolar transistors seems excessive; this topicis well covered in many books, sometimes in the space of afew pages.

None of the material is new, and none appears to bebased on original work by the author. The general level oftreatment is pedestrian and long-winded, so most practis-ing engineers will probably prefer more succinct authori-tative sources. What managers will gain from a book sodivorced from practical industrial situations, I do notknow.

D.J.H. MACLEAN

164 IEE PROCEEDINGS, Vol. 130, Pt. G, No. 4, AUGUST 1983