Graph of volts against frequency for HANN function

Discussion in 'Wireless & RF Design' started by derick007, Feb 7, 2016.

  1. derick007

    Thread Starter New Member

    Feb 5, 2013
    The graph of such a function is the well known sinc x function with an amplitude of 1/2v at f=0.

    This "total" sync function is the summation of 3 seperate sinc x functions. The first of these is similar to the "total" function in that it has an ampiltude of 1/2v at f=0.

    Assuming the HANN function contains a sinusoid of frequency f1, then the other 2 sinc x functions will be centred at f-f1 and f+f1 with amplitudes of 1/4v.

    I have found these 2 sinc functions to have a minus sign in front of them meaning their amplitudes are -1/4v at their centre frequncies. But any graphs I have found on the net, indicate they have amplitudes of +1/4v at their centre frequncies. It is though the minus sign has been ignored/forgotten.

    I have been struggling with the maths to see how it is possible to ignore the minus sign or how the maths can be used to change it from - to +?