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Student Support Forum: 'Cutoff Frequency' topicStudent Support Forum > General > Archives > "Cutoff Frequency"

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devil
02/02/13 2:06pm

Hi,

I want to calc the cutoff frequency.

I tryed for this the followed code, but don't work:

R1 = 1* 10^6;
C1 = 100 * 10^-9;

sys = (s*R1*C1)/(1 + s*R1*C1);
A = Abs[sys /. {s -> 2*Pi*fg*I}];

Solve[A == 1/Sqrt[2], fg]


--> I get the result:
{{fg -> (5 (I - Sqrt[2]))/(3*Pi)}, {fg -> (5 (I + Sqrt[2]))/(
3 Pi)}}

--> but it have to be 1/(2*Pi*R1*C1) = 5/Pi


Can someone please tell me, what I did wrong?

Many Thanks!

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Subject (listing for 'Cutoff Frequency')
Author Date Posted
Cutoff Frequency devil 02/02/13 2:06pm
Re: Cutoff Frequency yehuda 02/03/13 03:18am
Re: Cutoff Frequency devil 02/04/13 12:17pm
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