This book was intentionally written to be different from other filter design books
in two important ways. First, the most common analog and digital filter design and
implementation methods are covered in a no-nonsense manner. All important
derivations and descriptions are provided to allow the reader to apply them
directly to his or her own filter design problem. Over forty examples are provided
to help illustrate the fundamentals of filter design. Not only are the details of
analog active and digital IIR and FIR filter design presented in an organized and
direct manner, but implementation issues are discussed to alert the reader to
potential pitfalls. An added feature to this text is the discussion of fast Fourier
transforms and how they can be used in filtering applications. The simulation of
analog filters is made easier by the generation of PSpice circuit description files
that include R-C component values calculated directly from the filter coefficients.
In addition, the testing of IIR and FIR filters designed for audio signals is
enhanced by providing sample sound files that can be filtered by using the digital
filter design coefficients. Anyone with a sound card on their computer can then
play the original and processed sound files for immediate evaluation.
The second difference between this book and others is that the text is
accompanied by WFilter, a fully functional, Windows®-based filter design
software package, and the source code on which it is based. The CD provides the
reader with the ability to install WFilter with a few simple clicks of the mouse,
and also supplies the reader with the well organized and clearly documented
source code detailing the intricacies of filter design. No, the source code provided
is not just a collection of fragmented functions, but rather a set of three organized
programs that have been developed (with the addition of an easy-to-use graphical
interface) into the organized structure of WFilter.
A basic knowledge of C programming is expected of the reader, but the code
presented in the text and the appendixes is thoroughly discussed and well
documented. The text does assume the reader is familiar with the fundamental
concepts of linear systems such as system transfer functions and frequency
response although no prior knowledge of filter design is needed.