How to obtain the transfer function for Passive Bandpass Filter1?

Thread Starter

kitty10

Joined May 21, 2020
3
I'm got a question on how to obtain the transfer function for this RC Bandpass Filter in the phasor?

WBahn

Joined Mar 31, 2012
26,398
And what's your best attempt to answer that question?

RBR1317

Joined Nov 13, 2010
643
... in the phasor?
Does that mean you need to present the magnitude & phase of the transfer function in terms of the signal frequency?

MrAl

Joined Jun 17, 2014
8,266
I'm got a question on how to obtain the transfer function for this RC Bandpass Filter in the phasor?
View attachment 207750
How do you normally approach a circuit analysis problem?

Thread Starter

kitty10

Joined May 21, 2020
3
& phase of th
Does that mean you need to present the magnitude & phase of the transfer function in terms of the signal frequency?
Yes. That what I mean. I got the transfer function as complex number but I have a problem in convert it to phasor

Thread Starter

kitty10

Joined May 21, 2020
3
Yes. That what I mean. I got the transfer function as complex number but I have a problem in convert it to phasor
$Vout/Vin=(R1R2-jXc2R1)/((-jR1Xc1-jR2Xc1-Xc1Xc2+R1R2-jXc2R1)×(j R2/Xc2+1) )$

RBR1317

Joined Nov 13, 2010
643
Have you studied Bode plots yet? They show the magnitude & phase of a transfer function for a range of signal frequency.

The first step is to evaluate the entire expression, then separate and collect the real & imaginary parts. (That is a lot of complex algebra. I use a symbolic algebra engine -Maple- to avoid collecting piles of scribble paper.) Then use the real & imaginary expressions to calculate the magnitude & phase. (A lot more complex algebra.) At some point you will need to convert the capacitive reactance to a function of frequency.