Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

[SOLVED] Chebyshev Filters - example

Status
Not open for further replies.

matusel

Member level 1
Joined
Nov 13, 2009
Messages
40
Helped
3
Reputation
6
Reaction score
3
Trophy points
1,288
Activity points
1,540
Hello everybody i'm studiing the Chebyshev Filters and i would like to know if someone can post an example of a third order Chebyshev Filter.
 

rfmemo

Newbie level 3
Joined
Nov 4, 2011
Messages
3
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,297
what is the frequency specification of your filter?
 

matusel

Member level 1
Joined
Nov 13, 2009
Messages
40
Helped
3
Reputation
6
Reaction score
3
Trophy points
1,288
Activity points
1,540
Ok thankyou very much I needed this example because I have a doubt. In my book they say that the amplitude of a cebyshev filter oscillates in the pass band but the question is, if the transfer function has just poles how can the module (bode plot) oscillate (see ripple) ?
To oscillate there should be also zeroes!! In the oscillation the poles move the amplitude down of 20dB and the zeroes move it up...what is my mistake?

 

FvM

Super Moderator
Staff member
Joined
Jan 22, 2008
Messages
47,956
Helped
14,145
Reputation
28,549
Reaction score
12,830
Trophy points
1,393
Location
Bochum, Germany
Activity points
278,208
A Chebyshev type I filter has only poles, one real and a complex pair in case of 3rd order. Your simplified assumption about relation of poles/zeros and magnitude characteristic doesn't aplly to complex pole pairs, I think.
 

matusel

Member level 1
Joined
Nov 13, 2009
Messages
40
Helped
3
Reputation
6
Reaction score
3
Trophy points
1,288
Activity points
1,540
Thank you FvM And there is no way/rules to draw a bode diagram of amplitude of a couple of complex poles ?
 

FvM

Super Moderator
Staff member
Joined
Jan 22, 2008
Messages
47,956
Helped
14,145
Reputation
28,549
Reaction score
12,830
Trophy points
1,393
Location
Bochum, Germany
Activity points
278,208
I think, you can't sketch the magnitude without considering the pole quality factor. Below is an example of a second order Cheybyshev, which represents basically one complex pole pair.

 

matusel

Member level 1
Joined
Nov 13, 2009
Messages
40
Helped
3
Reputation
6
Reaction score
3
Trophy points
1,288
Activity points
1,540
Thank I think I've finally undersood
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top