Phase Linearization

1. What is phase linearity?
2. How do you calculate linear phase?
3. Why is phase linearity important?
4. What is linear and nonlinear phase?

What is phase linearity?

Linear-phase describes the response of a filter. When a signal goes through a filter, it experiences a time delay or phase shift. In a “perfect” filter, all frequencies should experience the same time delay (known as pure time delay), which preserves the wave shape as much as possible.

How do you calculate linear phase?

A linear-phase phase filter is one for which the continuous phase θ(ω) is linear. with θ(ω) = −M · ω + B.

Why is phase linearity important?

Linear Phase filters are desirable for certain applications because they maintain the shape of the input signal. Signals in the stop-band or transition-band may be severely attenuated but we can still see this effect in the pass-band.

What is linear and nonlinear phase?

Here is the important part: zero and linear phase filters have left and right edges that look the same, while nonlinear phase filters have left and right edges that look different. Many applications cannot tolerate the left and right edges looking different.