New resistor-less tunable floating and grounded FDNR simulators

Abstract

This article proposes new electronically tunable simulation configurations of synthetic grounded and floating frequency-dependent negative resistances (FDNRs) without using any resistances. The presented simulators have been realised by using two voltage differencing transconductance amplifiers (VDTAs) along with two capacitances. As per the knowledge of the authors, the depicted VDTA-based simulator circuits are the most compact configurations as compared to any other VDTA-based pure FDNR simulator reported so far. The circuits possess the feature of electronic tunability which means that the realised FDNR value can be controlled by using bias currents of employed VDTAs. Moreover, the reported structures simulate ideal FDNR behaviour without any requirement of fulfiling the parameter-related conditions. An analysis has been presented and discussed to find the behaviour of the presented circuits under non-ideal effects. The operation of the simulated FDNRs has been checked by constructing higher-order CDR filters. The working of the designed circuits has been shown through the simulation results generated using PSPICE with 0.18 um CMOS technology. Finally, the experimental results using commercial IC have been discussed.