A unified approach to orthogonal digital filters and wave digital filters, based on LBR two-pair extraction

The LBR-extraction approach is extended in order to derive wave digital filters and several orthogonal digital filters in a unified manner. The derivation clearly places in evidence the underlying orthogonality property of all these structures, which can therefore be implemented based on a simple building block, namely, the "planar rotation" operator. The derivation directly emphasizes the concept of "structural boundedness" as a requirement for low sensitivity. In addition to wave and orthogonal filters, a number of other methods for forcing structural boundedness are indicated.