Approximate linear phase Hilbert transformer

The IIR realization of the Hilbert transformer require less computations than FIR realizations, but the main disadvantage of the minimum phase IIR realization is the nonlinearity of the phase characteristic. In this paper, we show that using all-pass IIR subfilters from the minimal phase solution it is possible to design an IIR Hilbert transformer which exhibits simultaneously approximate constant amplitude response and approximate linear phase.