1 Filters and Tuned Amplifiers

Microelectronic Circuits - Fifth Edition Sedra/Smith2 Copyright  2004 by Oxford University Press, Inc. Figure 12.1 The filters studied in this chapter are linear circuits represented by the general two-port network shown. The filter transfer function T(s)  V o (s)/V i (s).

Microelectronic Circuits - Fifth Edition Sedra/Smith3 Copyright  2004 by Oxford University Press, Inc The Filter Transfer Function

Microelectronic Circuits - Fifth Edition Sedra/Smith4 Copyright  2004 by Oxford University Press, Inc First-order Filters

Microelectronic Circuits - Fifth Edition Sedra/Smith5 Copyright  2004 by Oxford University Press, Inc. Figure 12.2 Ideal transmission characteristics of the four major filter types: (a) low-pass (LP), (b) high-pass (HP), (c) bandpass (BP), and (d) bandstop (BS).

Microelectronic Circuits - Fifth Edition Sedra/Smith6 Copyright  2004 by Oxford University Press, Inc. Figure First-order filters.

Microelectronic Circuits - Fifth Edition Sedra/Smith7 Copyright  2004 by Oxford University Press, Inc. Figure First-order all-pass filter.

Microelectronic Circuits - Fifth Edition Sedra/Smith8 Copyright  2004 by Oxford University Press, Inc. Figure Definition of the parameters  0 and Q of a pair of complex-conjugate poles Second-Order Filters For filters, usually

Microelectronic Circuits - Fifth Edition Sedra/Smith9 Copyright  2004 by Oxford University Press, Inc. Figure (a) The second-order parallel LCR resonator. (b, c) Two ways of exciting the resonator of (a) without changing its natural structure: resonator poles are those poles of V o /I and V o /V i Second-Order LCR Filters

Microelectronic Circuits - Fifth Edition Sedra/Smith10 Copyright  2004 by Oxford University Press, Inc. Figure Realization of various second-order filter functions using the LCR resonator of Fig (b): (a) general structure, (b) LP, (c) HP, (d) BP, (e) notch at  0, (f) general notch, (g) LPN (  n   0 ), (h) LPN as s  , (i) HPN (  n   0 ).

Microelectronic Circuits - Fifth Edition Sedra/Smith11 Copyright  2004 by Oxford University Press, Inc. Figure Realization of the second-order all-pass transfer function using a voltage divider and an LCR resonator.

Microelectronic Circuits - Fifth Edition Sedra/Smith12 Copyright  2004 by Oxford University Press, Inc. Figure Second-order filtering functions.

Microelectronic Circuits - Fifth Edition Sedra/Smith13 Copyright  2004 by Oxford University Press, Inc. Figure (Continued)

Microelectronic Circuits - Fifth Edition Sedra/Smith14 Copyright  2004 by Oxford University Press, Inc. Figure (Continued)

Microelectronic Circuits - Fifth Edition Sedra/Smith15 Copyright  2004 by Oxford University Press, Inc. Figure 12.8 The magnitude response of a Butterworth filter Butterworth Filter: At

Microelectronic Circuits - Fifth Edition Sedra/Smith16 Copyright  2004 by Oxford University Press, Inc. Figure 12.9 Magnitude response for Butterworth filters of various order with e = 1. Note that as the order increases, the response approaches the ideal brick-wall type of transmission Butterworth Filter:

Microelectronic Circuits - Fifth Edition Sedra/Smith17 Copyright  2004 by Oxford University Press, Inc The Chebyshev Filter At

Microelectronic Circuits - Fifth Edition Sedra/Smith18 Copyright  2004 by Oxford University Press, Inc. Figure Sketches of the transmission characteristics of representative (a) even-order and (b) odd-order Chebyshev filters.