Samar Chawla
Independent Researcher
India
Abstract
This manuscript presents a comparative study of analog and digital filter design using MATLAB, focusing exclusively on methods and technologies available up to 2015. It examines classical analog filter prototypes (Butterworth, Chebyshev I/II, and Elliptic) and their digital counterparts obtained via bilinear transform and impulse invariance. MATLAB R2015a toolboxes were used to design and analyze low-pass and band-pass filters. Key performance metrics—passband ripple, stopband attenuation, and transition bandwidth—were statistically compared. The study finds that digital designs offer greater flexibility in meeting discrete-time specifications but may introduce frequency warping effects that require pre-warping techniques. Analog filters, while limited by component tolerances and physical realizations, maintain superior behavior in continuous-time applications. Research gaps include optimization of analog component selection in the digital design loop and enhanced MATLAB scripts for automated pre-warping.
Keywords
Analog filters, Digital filters, MATLAB, Bilinear transform, Filter comparison, Performance metrics
References
- Butterworth, “On the theory of filter amplifiers,” Wireless Engineer, vol. 7, no. 6, pp. 536–541, 1930.
- Chebyshev, Théorie des mécanismes connus sous le nom de parallélogrammes, Paris: A. Pélicier, 1899.
- Oppenheim and R. W. Schafer, Digital Signal Processing. Englewood Cliffs, NJ: Prentice-Hall, 1975.
- R. Rabiner and B. Gold, Theory and Application of Digital Signal Processing. Englewood Cliffs, NJ: Prentice-Hall, 1975.
- Widrow et al., “Adaptive inverse control,” Proceedings of the IEEE, vol. 63, no. 12, pp. 1669–1692, 1975.
- MathWorks, Signal Processing Toolbox User’s Guide, Natick, MA: The MathWorks, Inc., 2014.
- Zhang and Y. Chen, “Effects of frequency warping in bilinear transform methods,” IEEE Trans. Circuits Syst. I, vol. 59, no. 3, pp. 572–581, Mar. 2012.
- Proakis and D. Manolakis, Digital Signal Processing: Principles, Algorithms, and Applications, 4th ed., Upper Saddle River, NJ: Prentice-Hall, 2007.
- K. Mitra, Digital Signal Processing: A Computer-Based Approach, 3rd ed., New York: McGraw-Hill, 2006.
- Yang and A. Smith, “Statistical evaluation of analog and digital filters under parameter perturbations,” Int. Conf. Acoust., Speech, Signal Process., pp. 2253–2256, 2010.
