pavel_adameyko
Full Member level 4
Hello, dear friends
We know that definition of group delay is τ=-Δφ/Δω (1). Suppose we have system with phase response φ=-αω +β. According to formula (1) GD=α is constant. But consider two sinusoids with frequencies ω1 and ω2. Time delay for them would be t1=-φ1/ω1 = α-β/ω1, for the second - α-β/ω2. They are not equal. So the output of such system wouldn't be a shifted replica of input - i.e. the signal would be distorted. But how does this correlate with constant GD ???
Thanks in advance.
We know that definition of group delay is τ=-Δφ/Δω (1). Suppose we have system with phase response φ=-αω +β. According to formula (1) GD=α is constant. But consider two sinusoids with frequencies ω1 and ω2. Time delay for them would be t1=-φ1/ω1 = α-β/ω1, for the second - α-β/ω2. They are not equal. So the output of such system wouldn't be a shifted replica of input - i.e. the signal would be distorted. But how does this correlate with constant GD ???
Thanks in advance.