This course covers the fundamental and advanced concepts of microwave filter design, focusing on insertion loss, filter transformations, and practical implementation techniques. For instance, it explains insertion loss as the ratio of power from the source to the load, considering impedance mismatches and reflection coefficients. The course explores the frequency-dependent behavior of insertion loss and its representation using polynomials, introducing Butterworth, Chebyshev, and elliptic filters with their unique characteristics like flat passbands, sharp cutoffs, and ripple effects. It also delves into low-pass prototype designs, which serve as the basis for band-pass, high-pass, and band-stop filters. For example, learners calculate inductance and capacitance values for a Butterworth low-pass filter with specific parameters. Additionally, the course covers filter transformations, such as impedance and frequency scaling, and techniques like Richards' transformation and Kuroda's identities to replace lumped components with transmission line stubs for high-frequency applications.
This course has been developed by Prof. Amitava Bhattacharya from IIT Kharagpur for NPTEL. It is now accessible through Ansys Innovation Space courtesy of the partnership between Ansys and NPTEL, under the CC BY-SA license. For more details, visit https://nptel.ac.in/courses/117105138.