problem with signal

Discussion in 'General Electronics Chat' started by niloy2k, Mar 1, 2009.

  1. niloy2k

    Thread Starter New Member

    Mar 1, 2009
    Hi i am working on a project which is based on lock in amplification. Basically the main part of the design is the phase sensitive detection where demodulation(multiplication) of two signals takes place. For my project I have to extract a very weak signal buried in large noise. In the demodulator stage, it works fine if i just multiply a simple sine wave and a square wave havin da same phase as it provides me fully rectified signal. But if I add the noise signal with the sin wave and then perform the demodulation step, the output does not turn out to be fully rectified signal. I have tried lookin at all the specs but I cant figure out whats wrong with the procedure. Can anyone please please help me out with this ?? I will really appreaciate the help :)
  2. italo

    New Member

    Nov 20, 2005
    You may try the same approach for the noise and the results will be the noise dc then think of what can you do with that.