A new improvement to the Powell and Chau linear phase IIR filters
Branislav V. Djokic, Miodrag V. Popovic, M.D. Lutovac · IEEE Transactions on Signal Processing · 1998
An improvement to the realization of the linear-phase IIR filters is described. It is based on the rearrangement of the numerator polynomials of the IIR filter functions that are used in the real-time realizations proposed in literature. The new realization has better total harmonic distortion when a sine input is used, and it has smaller phase and group delay errors due to finite section length.