1. Thorough investigation of the principles and methodologies involved in active filters design.
2. Understanding the methods fore zero-pole control of transfer functions for the different types of active filters.
3. Analysis and computation of the sensitivity functions of active filters, in respect to a series of factors impacting the filter frequency response.
4. Distinction of the filter architectures, as well as the merits and drawbacks of the different filter structures, in relation to the circuitry complexity of real filters and the frequency response characteristics.
5. Analysis and design of various filter types, using a series of integrated design methodologies of multiple stages.
6. Constructive combination of the analytical design of the filter modules with the circuit characteristics of the finally obtained structures.
7. Emphasis is put on the realistic implementations of filter designs via a group of projects. The objective of the projects relate to both the analytical and circuit implementations. Fulfilment of the design specifications in analytical and circuitry level is achieved using several software packages (MATLAB, Simulink, EWB, SPICE).
Course Content (Syllabus)
Different types of analog active filters, transfer functions, frequency response, Bode diagrams. Amplitude, frequency and time scaling. Operational amplifiers (OA)- basic principles and configurations, bilinear transfer functions.
First order filters- Passive and active implementations. Second order circuits (Biquads). Root locus, sensitivity functions, statistical analysis of gain sensitivities. Zero-pole control via active sources.
Implementations of second order circuits with different frequency response (low-pass, high-pass, band-pass, band-rejection) using positive and negative feedback strategies. Implementations of second order transfer functions using infinite gain OAs. Generalized second order circuits and circuits with multiple OAs.
Design methods of passive filters with different response characteristics. Design of low-pass active filters: Butterworth, Chebyshev, Inverse Chebyshev, Cauer, Bessel-Thomson.
Frequency transformations. Band-pass filters design, zero-pole transformations, Geffe algorithm.
Design of high-pass, band-rejection active filters. Design of Bessel-Thomson active filters, phase and signal delay, transfer functions and frequency response of delay filters.
Active filter designs incorporating generalized impedance converters (GICs) and switching capacitors (SC).
Course Bibliography (Eudoxus)
1. Αναλογικά Φίλτρα, Σπύρος Α. Πακτίτης, Εκδόσεις Ίων (4η έκδοση 2007) ΑΘΗΝΑ, ISBN: 978 – 960 – 411 – 641 – 6, ΚΩΔ.ΕΥΔ.: 14454
2. “Analog Filter Design” [Hardcover] by M. E. Van Valkenburg, Oxford University Press, USA, ISBN-10: 0195107349, 1995.
3. “Design of Analog Filters”, by Rolf Schaumann and Mac E. Van Valkenburg, Oxford University Press, USA, ISBN-10: 0195118774, 2001.