one/F noise source ckt?

[Magnus Danielson]

From: patchell <patchell at silcom.com>
Subject: Re: one/F noise source ckt?
Date: Sun, 03 Sep 2000 13:41:43 -0700

>     I found what you need in one of my Active Filter books.  To get a "true" -3db
> per octave rolloff, you need to use a resistor with ditributed capacitance.  If
> you were to model this with lumped components it would be equivilent to an
> infinate number of resistors in series with an infinate number of shunt
> capacitors.  The only draw back to this is I somehow don't think you are going to
> find anybody selling such a component.

Oh, yes... they are called capacitors ;D

Good old big-bearded Bob Pease has written about capacitors and to model them
correctly you need a distributed cap/resistor network. I do wounder however if
they even approximate values which are suitable for the - 3 dB/Oct curve.

However, it is true that it would require an infinitly long sequence to make
a true filter. We could make approximations to within some limits and within
some frequency span.

Cheers,
Magnus