# Tag Info

Delay is the negative derivative of phase with respect to frequency. Phase that increases linearly negative as frequency increases will result in a positive (later) delay in time. This is given by the Fourier Transform property of time delay: $$\mathscr{F} \{f(t-\tau)\} = e^{-j\tau \omega}F(\omega)$$ And is easy to prove from the Fourier Transform: \...