Register to reply 
Frequency response of a transfer function 
Share this thread: 
#1
May609, 06:35 PM

P: 145

If I have a transfer function, and I need the frequency response of it, how do I go about doing it?
Is there a easier way than inverse Laplace transforming it, then Fourier transforming that? Thanks 


#2
May609, 06:38 PM

Emeritus
Sci Advisor
PF Gold
P: 10,427

In what variable is your transfer function specified? z? s?
 Warren 


#3
May609, 07:41 PM

P: 145

it is in terms of s.



#4
May709, 12:47 AM

Mentor
P: 40,961

Frequency response of a transfer function
If you have the transfer function in terms of s, you will just plot the real an imaginary parts of it versus frequency.... (or the magnitude and phase as a function of frequency, like you get on an impedance analyzer). 


#5
May709, 12:58 AM

Sci Advisor
P: 1,724

Might want to take a look at this thread, on transfer functions:
http://www.physicsforums.com/showthread.php?t=312140 EDIT: Wait, that's your thread! Never mind then... 


#6
May709, 01:06 AM

Mentor
P: 40,961




#7
May709, 01:14 AM

Sci Advisor
P: 1,724




#8
May709, 01:18 AM

Mentor
P: 40,961




#9
May709, 02:13 AM

P: 145

Thanks :) Anyway, [tex]s = i \omega[/tex]. I was suposed to plot the frequency response of the transfer function, which was easily done in MATLAB, but I want to know the theory behind it. Thanks again 


#10
Sep1211, 12:42 PM

P: 1

In order to get the Frequency response from the transfer function, you just need to plus in jω for all s. Assuming it exists, this will be your frequency response, aka the Fourier transform of your original signal in the time domain.
I know this is an old forum... but I figure this may help anyone looking at this in the future. 


Register to reply 
Related Discussions  
Transfer function to impulse response  Engineering, Comp Sci, & Technology Homework  2  
Frequency Response Function analysis in ANSYS  Mechanical Engineering  2  
Transfer Function, Impulse Response  Calculus & Beyond Homework  0  
Frequency response function  Engineering, Comp Sci, & Technology Homework  1 