Starting from the fundamentals, the present book describes methods of designing analog electronic filters and illustrates these methods by providing numerical and circuit simulation programs. The subject matters comprise many concepts and techniques that are not available in other text books on the market. To name a few - principle of transposition and its application in directly realizing current mode filters from well known voltage mode filters; an insight into the technological aspect of integrated circuit components used to implement an integrated circuit filter; a careful blending of basic theory, numerical verification (using MATLAB) and illustration of the actual circuit behaviour using circuit simulation program (SPICE); illustration of few design cases using CMOS and BiCMOS technological processes.