Analog Filters

Preface.- 1 Introduction.- 1.1 Preliminary remarks.- 1.2 The analog filter.- 1.3 Ideal and approximate filter characteristics.- 1.4 MATLAB.- 1.5 Circuit analysis.- 1.6 Normalization and denormalization-scaling.- 1.7 Steps involved in the design of filters.- 2 The approximation.- 2.1 The Butterworth lowpass characteristic.- 2.2 The Chebyshev lowpass characteristic.- 2.3 Other Chebyshev-related characteristics.- 2.4 The elliptic-function filter characteristic.- 2.5 Comparison of standard lowpass characteristics.- 2.6 Summary.- 3 Network functions.- 3.1 General procedure.- 3.2 Network functions for Butterworth filters.- 3.3 Network functions for Chebyshev filters.- 3.4 Network functions for elliptic-function filters.- 3.5 Bessel-Thomson filter functions.- 3.6 Delay equalization.- 3.7 Summary.- 4 Frequency transformation.- 4.1 Lowpass-to-highpass transformation.- 4.2 Lowpass-to-bandpass transformation.- 4.3 Lowpass-to-bandreject transformation.- 4.4 Summary.- 5 Properties and synthesis of passive networks.- 5.1 The driving-point function of a passive oneport - the positive real function.- 5.2 The driving-point function of a lossless oneport - the lossless function.- 5.3 Properties of lossless twoports.- 5.4 LC ladder twoport.- 5.5 Foster’s preamble.- 5.6 Summary.- 6 Singly-terminated LC ladders.- 6.1 LC ladder with a current source.- 6.2 LC ladder with a voltage source.- 6.3 Other singly-terminated orientations.- 6.4 Summary.- 7 Doubly-terminated LC ladders.- 7.1 Basic formulation.- 7.2 LC ladders with equal terminations.- 7.3 LC ladders with unequal terminations.- 7.4 A doubly-terminated filter used in reverse.- 7.5 Summary.- 8 Sensitivity.- 8.1 Definition of sensitivity.- 8.2 Properties of first-order sensitivity.- 8.3 Sensitivities of network performance.- 8.4Sensitivity calculation.- 8.5 Unnormalized sensitivity.- 8.6 Multiparameter and statistical sensitivities.- 8.7 A case for low sensitivity of passive filters.- 8.8 Summary.- 9 Basics of active filters.- 9.1 Comparison of passive and active filters.- 9.3 Some simple op amp circuits.- 9.4 First-order sections.- 9.5 RC single-op amp circuit relationships.- 9.6 Gain adjustments.- 9.7 RC-CR transformation.- 9.8 Types of biquads.- 9.9 Summary.- 10 Biquad circuits.- 10.1 Sallen-Key biquads.- 10.2 Infinite-gain multiple-feedback (MFB) biquads.- 10.3 The two-integrator biquads.- 10.4 Summary.- 11 High-order active filters.- 11.1 The cascade realization.- 11.2 The state-variable method of realization.- 11.3 Lowpass-to-bandpass transformation.- 11.4 Internal gain change.- 11.5 Summary.- 12 Active simulation of passive filters.- 12.1 Some active twoports.- 12.2 The generalized impedance converter (GIC).- 12.3 Simulation of inductances in an LC ladder.- 12.4 Simulation using frequency-dependent negative resistances (FDNR’s).- 12.5 Functional simulation of passive filters.- 12.6 Summary.- 13 Switched-capacitor filters.- 13.1 An introduction.- 13.2 Simulation of resistors by switched capacitors.- 13.3 Simple basic circuits.- 13.4 Switched-capacitor biquads.- 13.5 Functional simulation of LC ladders.- 13.6 Summary.- Appendix A Tables of filter functions.