A new approach for synthesis of low sensitivity digital filter structures based on lossless building blocks

In a recent paper [1], it is shown that a fundamental requirement for low passband sensitivity realization of a digital transfer function is that the implementation be structurally passive, or bounded. In this paper, a general procedure for developing low-sensitivity realizations of a transfer function is advanced. The resulting structures are in the form of a cascade connection of basic digital two-pair structures satisfying a "lossless" property in the z-domain. The methods advanced here cover the well-known wave digital filters and the Gray-Markel lattices as special cases. The synthesis procedure is entirely z-domain based, and does not make reference to continuous time networks, unlike the wave digital filters which are designed starting from a continuous time network.