How to Design Nonlinear Phase FIR Filter?

1. Can FIR filters have linear phase?
2. Why FIR filters have linear phase?
3. Which of the following technique is more preferable for design of linear phase FIR?

Can FIR filters have linear phase?

FIR filters are usually designed to be linear-phase (but they don't have to be.) A FIR filter is linear-phase if (and only if) its coefficients are symmetrical around the center coefficient, that is, the first coefficient is the same as the last; the second is the same as the next-to-last, etc.

Why FIR filters have linear phase?

The FIR filters have a phase response that traces out a straight line. Both of these FIR filters exhibit linear phase [1][2]. This means that those sinusoidal components are given a constant phase shift and that the phase shift is constant relative to each frequency.

Which of the following technique is more preferable for design of linear phase FIR?

Which of the following technique is more preferable for design of linear phase FIR filter? Explanation: The chebyshev approximation method provides total control of the filter specifications, and as a consequence, it is usually preferable over the other two methods.