Multiple-Input Describing Functions and Nonlinear System Design

This book is intended to provide a comprehensive documentation of describing function theory and application. It begins with a unified theory of quasi-linear approximation to nonlinear operators within which are embraced all the useful describing functions. It continues with the application of these describing functions to the study of a wide variety of characteristics of nonlinear-system operation under different input conditions. Emphasis is given to the design of these nonlinear systems to meet specified operating characteristics. The book concludes with a complete tabular and graphical presentation of the different describing functions discussed in the text, corresponding to a broad family of nonlinear functions. Dealing as it does with the single subject of describing functions, the book would seem to be very specialized in scope. And so it is. Yet the range of practical and important questions regarding the operation of nonlinear systems which this family of describing functions is capable of answering is so broad that the writers have had to set deliberate limits on the lengths of chapters to keep the book within reasonable size. Thus the subject is specialized to a single analytical tool which has exceedingly broad applicability.