NAM expansion method for systematic synthesis of OTA-based floating gyrators

This paper presents a NAM expansion method for systematically synthesizing OTA-based floating gyrators. After describing nullor-mirror components of OTAs, class I, II and III gyrators, which can be built with standard OTAs, are synthesized by using the nullor-mirror equivalent models described by NAM. The class-I gyrators employing two DO-OTAs have four equivalent realizations, the class-II gyrators employing three SO-OTAs have eight equivalent realizations, and the class-III gyrators employing four SISO-OTAs have 16 equivalent realizations. Having used canonic number of components, the circuits are easy to be integrated and their parameters can be tuned electronically through tuning bias currents of OTAs. Finally, as an example, the MULTISIM simulation results of a notch filter constructed by the OTA-based III gyrator are presented to verify the realizability of the derived circuits.