Transfer Function of analog filters

[Magnus Danielson]

>>>>> "GR" == Gordon Ramsay <g.ramsay at easynet.co.uk> writes:

 GR> Hello, 
 
 GR> I have been trying to get to grips with some of the fundimentals
 GR> of analog filter design for a project I am doing at the moment,
 GR> and was wondering if anyone knows of any good resources for
 GR> explaining the Laplace and Bilinear Transform, and generally
 GR> reaching the transfer functions of a 24dB/octave resonant Low
 GR> Pass. I am currently trawling through Van Valkenberg(Analog
 GR> Filter Design) but it is causing me much trauma. 

Well, for many of the fundamentals I use the book "Filtering in the
Time and Frequency Domains" by Herman J. Blinchikoff and Anatol
I. Zverev published by Krieger. It has a strong emphasis towards
analog filters but also goes into digital filter designs and this
includes the bilinear transform. It is very readable.

As you move into the digital domain I recommend "Theory and
Application of Digital Signal Processing" of Rabiner and Gold as well
as "Digital Signal Processing" by Oppenheimer and Schafer. Both is
being classic and for a good reason, both are also higly
readable. These books are twins to some degree and while they both cover
some things you will also find that one may just mention something
while the other goes into all the gory details.

There are certainly many newer titles which covers the latest in this
or that, but these books remains very good friends as you learn and
improve you skills. You will find that many other books reference
these books, so why not just get them?

The Blinchikoff/Zverev book discusses a lot around 2-pole, 3-pole,
4-pole etc filters in a very generic way while not locking up in a
discussion on peculiareties in this or that component topology. This
helps to get the understanding of what the filters are supposed to do.
Then they go into how to synthesize filters for a certain topology ;)

The transfer function of a 24 dB/oct LP (thus, a 4-pole filter) is
certainly not a hard thing to learn from such a good book. Once one
has grasped the concept of poles and zeros and their position in
either the s-plane and z-plane the fogg will start to deminish.

Analog Cheers,
Magnus