---
+ Post New Thread
Results 1 to 5 of 5
  1. #1
    Newbie level 6
    Points: 866, Level: 6

    Join Date
    Feb 2009
    Posts
    13
    Helped
    0 / 0
    Points
    866
    Level
    6

    What is importance of frequency domain analysis over time ?

    Why signals are mostly studied in frequency domain?

    •   Alt9th February 2009, 14:30

      advertising

        
       

  2. #2
    nl5
    nl5 is offline
    Junior Member level 1
    Points: 1,074, Level: 7
    nl5's Avatar
    Join Date
    Jan 2009
    Posts
    17
    Helped
    4 / 4
    Points
    1,074
    Level
    7

    What is importance of frequency domain analysis over time ?

    I think, because if you know frequency response of the system, you can easily predict its response in time domain for any type of input signal. (And vice-versa as well). Another reason could be well known technique of determining system stability based on frequency response.



    •   Alt9th February 2009, 16:30

      advertising

        
       

  3. #3
    Newbie level 6
    Points: 866, Level: 6

    Join Date
    Feb 2009
    Posts
    13
    Helped
    0 / 0
    Points
    866
    Level
    6

    What is importance of frequency domain analysis over time ?

    can you be more clear.



    •   Alt10th February 2009, 12:49

      advertising

        
       

  4. #4
    nl5
    nl5 is offline
    Junior Member level 1
    Points: 1,074, Level: 7
    nl5's Avatar
    Join Date
    Jan 2009
    Posts
    17
    Helped
    4 / 4
    Points
    1,074
    Level
    7

    Re: What is importance of frequency domain analysis over ti

    Quote Originally Posted by nl5
    if you know frequency response of the system, you can easily predict its response in time domain for any type of input signal.
    This must be not a simplest explanation, but anyway...

    Every system has a transfer function in frequency domain: T(ω). Very often it is done not as a function of frequency ω (ω=2πf), but Laplace parameter s=jω: T(s).
    If you apply signal f(t) to the system and want to know output g(t), there is a simple formula in frequency domain:
    G(s) = T(s)*F(s),
    where G(s) and F(s) are Laplace transforms of g(t) and f(t).
    So, you have f(t), then found F(s), multiply by T(s), get G(s), performe inverse Laplace transform to obtain g(t).

    Quote Originally Posted by nl5
    Another reason could be well known technique of determining system stability based on frequency response.
    This is part of control theory. Simple example is using gain and phase margins on Bode plot to analyse stability of the closed loop system. Here is a link.

    Thank you.



  5. #5
    Advanced Member level 1
    Points: 4,634, Level: 16
    xulfee's Avatar
    Join Date
    May 2008
    Location
    Pakistan
    Posts
    401
    Helped
    52 / 52
    Points
    4,634
    Level
    16

    What is importance of frequency domain analysis over time ?

    we can see some poles n zeros of system easily to check abt system stability



+ Post New Thread
Please login