Chief

INTRODUCTION

Digital filters have a relevant importance in electronic systems because they are present in almost any electronic system. For example, communication systems make intensive use of filtering to separate unwanted noise from the desired signal. Power supplies use filters to reject ripple and improve the dc signal quality. Audio equalizers use filters to amplify or attenuate bands in the audio range to improve audio quality depending upon room acoustic characteristics. Digital video needs digital filters to reduce noise due to coding and transmission through a noisy channel, and so on. Unfortunately, filter design is an intensive computational task requiring a significant amount of numerical calculations to obtain either the parameters of a filter transfer function or the element values for a filter circuit realization. On the other hand, computer usage has reached every corner in everyday life. Thus, computer software development has become an important part of technological development. An area that has been most influenced by this development is education.

Nowadays, there exist a large number of software packages especially dedicated to filter design, but they have several drawbacks. One of the most important is that those packages have a very high price. This report describes a software package whose purpose is to provide a tool to be used as a teaching aid in analog and digital filter design courses. The feature of this package is that it uses MATLAB for the numerical computations and thus it is called MFILTERS. MATLAB is now available in any university or industry, and it is used, among many other things, in the design of circuits and systems. One of the main characteristics of MATLAB is the availability of a set of toolboxes almost ready to be used in the design of filters. Unfortunately, use of these toolboxes requires a considerable length of time to master them, thus discouraging novice