lec27

# lec27 - 1 1 Summary of Lecture#27 • Analog filters •...

This preview shows pages 1–2. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 1 1 Summary of Lecture #27 10/28/09 • Analog filters • Realization of LP filters, examples • Transformation from LP to HP, BP and BR • Frequency and magnitude scalingT • Transformation from LP filters to HP filters • An example of HP filters • See me before next Friday, Nov. 6, 2009 • If your test 2 score is less than 25. 2 Low pass filters • Ideal specification of low pass filters – Brick wall specification – |H(j ϖ )| = 1 for ϖ ϖϖ < ϖ p – |H(j ϖ )| = 0 for ϖ ϖϖ > ϖ p • Realization or approximation – Butterworth low pass transfer characteristic (maximum flat in pass band) – Chebyshev low pass transfer characteristic (equal ripples in pass band) – Inverse Chebyshev low pass transfer characteristic (equal ripples in stop band) – Elliptic low pass transfer characteristic – (equal ripples in pass and stop bands) • Prototype circuit with ϖ p = 1 rad/s, rate of roll off and 1- ohm impedance level • Frequency and magnitude scaling • 2 examples, by coefficient matching |H(j ϖ )| 1 ϖ p ϖ 3 Max. flat in pass band Equal ripples in pass band Equal ripples in stop band Equal ripples in pass and stop bands |H|’, |H|”, |H|’” … are 0 dB at ϖ = 0. 4 Ex. 2. Design a LP filters with ϖ p = 218.7 π rad/s , a roll off rate of 60 dB/dec . and for a 100 Ω load. 60 dB/dec. → third order filter By applying KCL to nodes 1 and 2, we obtain 2 1 2 1 2 1 2 2 1 3 2 1 C LC 2 s C LC C C L s ) C 1 C 1 ( s ) C LC /( 1 ) s ( H + + + +...
View Full Document

## This document was uploaded on 02/18/2010.

### Page1 / 4

lec27 - 1 1 Summary of Lecture#27 • Analog filters •...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online