Power spectrum analysis
时间：04-04
整理：3721RD
点击：
if f(t) = sin(2*pi*f1*t) + 0.5*sin(2*pi*f2*t) then
Fourier Transform, F(f) = 1 / 2j { delta (f - f1) - delta (f + f1) + 0.5 delta (f - f2) - 0.5 delta (f + f2) }
Ignoring negative frequencies :
F(f) = -j { 0.5 delta (f - f1) + 0.25 delta
"F(f)|^2 = 0.25 delta (f - f1) + 0.0625 delta (f - f2) ; f1=390.6 Hz : f2=3.125 kHz
Now apparently if we integrate this the answer is 61.035, but I cannot see how this is achieved.
I thought by integrating, the 2 delta functions would just be added i.e. 0.3125
Fourier Transform, F(f) = 1 / 2j { delta (f - f1) - delta (f + f1) + 0.5 delta (f - f2) - 0.5 delta (f + f2) }
Ignoring negative frequencies :
F(f) = -j { 0.5 delta (f - f1) + 0.25 delta
"F(f)|^2 = 0.25 delta (f - f1) + 0.0625 delta (f - f2) ; f1=390.6 Hz : f2=3.125 kHz
Now apparently if we integrate this the answer is 61.035, but I cannot see how this is achieved.
I thought by integrating, the 2 delta functions would just be added i.e. 0.3125