Representation/Effect of a delay element in the frequency domain?

[amsdesign]

If I have a simple RC low pass filter in which the output is taken across the capacitor, with a particular cut off frequency say x Hz.

Now if I were to introduce a delay in the path of the resistor, how will the bandwidth of the LPF change? How do I visualize this delay in the frequency domain?

 

[FvM]

A pure delay (e.g. an ideal delay line) shows as frequency dependent phase shift in the frequency domain but doesn't affect the magnitude. In complex signal math, the delay is represented by a rotation operation:

H(jw) = exp(-jωT)

 

[amsdesign]

A pure delay (e.g. an ideal delay line) shows as frequency dependent phase shift in the frequency domain but doesn't affect the magnitude. In complex signal math, the delay is represented by a rotation operation:

H(jw) = exp(-jωT)

Hi FvM,

But in a DLL, doesn't the gain of the delay line affect the bandwidth?

 

[FvM]

1. You have been asking about delay not gain.
2. Delay in a feedback loop affects the phase margin and in so far the closed loop behaviour