negative frequency and reflected signal

Discussion in 'Wireless & RF Design' started by tomshong, Feb 24, 2012.

  1. tomshong

    Thread Starter Member

    Oct 6, 2011
    36
    0
    From my reading on quadrature signals, any real life periodic signal can be represented as a sum of cosine and sine. Cosine is the sum of two phasers rotating in opposite direction. Sine is the difference of the phasers.

    So if the ‘negative frequency’ is the phaser component driven in the ‘opposite direction’. Does that mean, whenever I read about a transmission line where there’s reflected and transmitted signal, that the ‘negative frequency’ is the same as the ‘reflected signal’ in a transmission line?

    Somehow I doubt that's the case, but I'd like to hear you experts take on it.
     
    Last edited: Feb 24, 2012
  2. nsaspook

    AAC Fanatic!

    Aug 27, 2009
    2,908
    2,169
    Define ‘negative frequency’.
     
  3. tomshong

    Thread Starter Member

    Oct 6, 2011
    36
    0
    From what I understand, if I stop thinking in term of frequency and amplitude and start thinking in phasors, then it can be shown that sine and cosine are made of two quantieis called phaser, where there's a positive phaser e^jwt, and negative phaser e^-jwt, and that's where the 'negative frequency' component comes in.
     
  4. bertus

    Administrator

    Apr 5, 2008
    15,648
    2,346
    Hello,

    The negative sign denotes probably a 180° phase shift.

    Bertus
     
Loading...