Drawing Bode plots...

[David]

I'm working through Sedra/Smith's Microelectronic Circuits and would like to
find a tutorial on drawing Bode plots both by hand and using computer
software.

I did see several sites discussing using MATLAB to accomplish this so the
by-hand methods are what I'm most interested in.

 

[Stephen J. Rush]

On Sun, 23 Sep 2007 23:27:50 -0400, David wrote:

I'm working through Sedra/Smith's Microelectronic Circuits and would like to
find a tutorial on drawing Bode plots both by hand and using computer
software.

I did see several sites discussing using MATLAB to accomplish this so the
by-hand methods are what I'm most interested in.

You mean the familiar amplitude / frequency plot? Just get 3- or 4-cycle
semi-logarithmic graph paper. If the nearest office-supply store doesn't
have it, a university bookstore certainly will. Generating a logarithmic X
scale by hand sounds really tedious. A ruler and the log function of a
calculator? Pull the slide out of a slide rule so you can use the C scale
for a ruler?

 

[David]

"Stephen J. Rush" <sjrush@comcast.net> wrote in message
newsO-dnTcX2M-1z2rbnZ2dnUVZ_u7inZ2d@comcast.com...

On Sun, 23 Sep 2007 23:27:50 -0400, David wrote:

I'm working through Sedra/Smith's Microelectronic Circuits and would like
to
find a tutorial on drawing Bode plots both by hand and using computer
software.

I did see several sites discussing using MATLAB to accomplish this so the
by-hand methods are what I'm most interested in.

You mean the familiar amplitude / frequency plot? Just get 3- or 4-cycle
semi-logarithmic graph paper. If the nearest office-supply store doesn't
have it, a university bookstore certainly will. Generating a logarithmic
X
scale by hand sounds really tedious. A ruler and the log function of a
calculator? Pull the slide out of a slide rule so you can use the C scale
for a ruler?

Well even with log paper I notice the plots usually have curves to them...
Would you usually only plot the linear portions and then estimate the
curves?

 

[Eeyore]

David wrote:

I'm working through Sedra/Smith's Microelectronic Circuits and would like to
find a tutorial on drawing Bode plots both by hand and using computer
software.

I did see several sites discussing using MATLAB to accomplish this so the
by-hand methods are what I'm most interested in.

What's the problem ? It's a graph with frequency on the x-axis and gain on the
y-axis.

Typically, a logarithimic scale is used so as to display the wide range of
values conveniently.

In MATLAB etc, use the graphing tool.

Graham

 

[JeffM]

David wrote:

would like to find a tutorial on drawing Bode plots
both by hand and using computer software.

Stephen J. Rush wrote
[...]Just get 3- or 4-cycle semi-logarithmic graph paper.
If the nearest office-supply store doesn't have it,
a university bookstore certainly will.

That's so 20th Century.

Generating a logarithmic X scale by hand sounds really tedious.

Welcome to the Computer Age.

http://www.google.com/search?q=cache:Vv7zKVyh9BEJharm.kuleuven.be/pharbio/gpaper.htm+music.manuscripts+graph.papers+I.distribute.my.software.freely+Windows+to.download+no.entry+*-application-*-to-print++registry+pattern.papers+No.DLL.files

David wrote:

Well even with log paper I notice the plots usually have curves to them...
Would you usually only plot the linear portions
and then estimate the curves?

Simple technique:

1) Plot as many data points as it takes
to be confident you have the curve right.

2) Connect the dots.

 

[Rich Webb]

On Sun, 23 Sep 2007 23:27:50 -0400, "David" <davidd31415@yoowhoo.com>
wrote:

I'm working through Sedra/Smith's Microelectronic Circuits and would like to
find a tutorial on drawing Bode plots both by hand and using computer
software.

I did see several sites discussing using MATLAB to accomplish this so the
by-hand methods are what I'm most interested in.

As alternatives to Matlab, take a look at:
Scilab (free-as-in-beer; see their license regarding commercial use
(summary: okay but don't modify it)) at http://www.scilab.org/,
Octave (GNU) at http://www.gnu.org/software/octave/, and
OMatrix (not free but not too expensive) at http://www.omatrix.com/

IIRC, you can also do log-log and semilog plots with MS Excel and
most/many other spreadsheets. (See OOo).

My program of choice for this is Mathcad. I don't recommend it any
more, based on the rather restrictive licensing scheme they went to.
My old-but-working 2001i is just fine, thankyouverymuch.