Complex wave digital ladder filters using complex port references
Gordon B. Scarth, Gert O. Martens · 1991
Complex wave digital ladder filters are realized using a generalization, to the complex domain, of voltage wave digital filters. The port references are now allowed to be complex and all of the familiar wave digital concepts are preserved. The filters realized do not require the property of one-realness. Necessary complex wave digital equivalents are derived for both the dynamic and nondynamic one-ports, as well as for the nondynamic two-ports. The complex 3-port series and parallel adaptors are derived and the scattering matrix of the reflection-free 3-port series adaptor is found to be identical to the real case. Ladder filters are realized using complex reference networks that contain general reciprocal first-order sections. Realizations composed exclusively of inductors (complex parallel adaptors) or capacitors (complex series adaptors) are possible. An illustrative example is also given.>