{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

lec29

# lec29 - Summary of Lecture#29 Analog filters General...

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

1 1 Summary of Lecture #29 11/02/09 Analog filters General procedure Prototype LP filters Transformation from LP filters to HP filters Frequency and magnitude scaling An example of RLC HP filters Two examples of active HP filters Filter realization based on brick wall specification Find n and ϖ c from ϖ p , ϖ s , A max and A min Examples 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 0 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 Realization of high pass filters Low pass filters with ϖ c = 1 rad/s and 1 LP to HP Transformation : s 1/s Inductor in LP filter capacitor in HP filter Capacitor in LP filter inductor in HP filter Frequency scaling ( K f ) to desired ϖ c Magnitude scaling ( K m ) to desired impedance level LP HP LP LP LP L HP P 1 1 L s , L s ( )s L C s 1/ L 1/ L C = = = LP HP HP LP LP L P P L 1 L L 1/ C C 1 s C s s, C C s = = = 5 Ex. 6 A high pass RLC filter Design a second-order Butterworth HP filter with f c = 5500 Hz and two 1000 resistors. Begin with a LP filter of ϖ c = 1 rad/s and 1 .

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.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern