Half-band FIR fractional delay filters with closed-form coefficient formulas and modular implementation based on Lagrange interpolators

The Taylor series-based representation of the maximally flat (MF) FIR fractional delay (FD) filter is manipulated to obtain a FD filter with a wider band-width. The band-width of the proposed filter can approach π/2rads/s, which is 1.5 times that of the prototype one. The design has closed-form coefficient formulas as well as a modular implementation. These two properties make it a practically favourable one.