ENEX301
Filter Design
Syllabus
- Introduction
- Filter, its evolution and importance
- Lowpass, highpass, bandpass, bandstop, allpass, passive and active filters
- Filter response: Ideal (Brick wall) response and practical response
- Filter parameters: Gain, attenuation, passband, stopband and transition band
- Filter transfer function, frequency response, poles, zeros and their roles
- Normalization and de-normalization in filter design
- Impedance (Magnitude) scaling and frequency scaling
- Approximation Methods
- Approximation and its importance in filter design
- Low pass approximation methods
- Butterworth approximation
- Chebyshev (Chebyshev type I) approximation
- Inverse Chebyshev (Chebyshev type II) approximation
- Cauer (Elliptic) approximation
- Bessel-Thomson response
- Delay equalization
- Frequency Transformation
- Frequency transformation and its importance in filter design
- Low pass to high pass transformation
- Low pass to band pass transformation
- Low pass to band stop transformation
- Properties and Synthesis of Passive Networks
- One-port passive circuits: properties, positive real functions, lossless functions, synthesis of LC one-port circuits, Foster and Cauer realizations, RC one-port functions
- Two-port passive circuits: properties, residue condition, zeros of transmission, zero shifting by partial removal of a pole, synthesis of two port LC and RC ladder circuits
- Design of Resistively-Terminated Lossless Filters
- Properties of resistively-terminated lossless ladder circuit, transmission and reflection coefficients
- Synthesis of LC ladder circuits to realize all-pole low pass functions and functions with finite transmission zeros
- Design of Active Filters
- First order active filters (Bilinear)
- Second order active filters (Biquads): Tow-Thomas and Sallen-Key biquad circuits
- Higher order active filters: cascade of biquads, simulated inductors, gyrator and GIC, FDNR, leapfrog simulation of LC ladders
- Sensitivity
- Sensitivity and importance of sensitivity analysis
- Single parameter sensitivity
- Centre frequency and Q-factor sensitivity
- Sensitivity of biquads and passive filters
- Other Filters
- Switched Capacitor Filters
- Current mode filters
- Adaptive Filters
- Current Conveyors