Closed-Form Design of Maximally Flat IIR Hilbert Transformer With Integer Delay.

This paper presents the closed-form designs of an infinite-impulse-response (IIR) Hilbert transformer with an integer delay. The maximally flat criterion is applied at the midband frequency \pi/2. These designs are further categorized into eight types according to the filter orders and the delay values being even or odd. Their coefficients can be explicitly solved in closed form. A recursive relation also exists, facilitating the computation of these coefficients. Moreover, under the suggested relations and formula for the design parameters based on the Eneström–Kakeya theorem, we can obtain a satisfactory stable IIR Hilbert transformer. [ABSTRACT FROM PUBLISHER]