Tunable Ladder-Type Realization of Current-Mode Elliptic Filters

It is shown that a new series FDNR-R equivalent circuit using current controlled current conveyors (CCCIIs) allows effective realization of jω-axis zeros which are known to complicate the active implementation of ladder-type elliptic filters. The resulting ladder-type elliptic filter employs all grounded capacitors while keeping the number of active elements small. Also, the filter parameters are electronically tunable, which is important from integration point of view.