Frequency dependent negative resistor based on differential-input buffered and transconductance amplifier

The purpose of the paper is to introduce a novel application of the modern active building block, namely Differential-input Buffered and Transconductance Amplifier (DBTA). The circuit proposed is a Frequency Dependent Negative Resistor (FDNR), which requires one DBTA and only two grounded capacitors. These features make it suitable for full integration on a chip. For the purpose of experimental verification, the proposed circuit was implemented using commercially available components and properly tested in an application of ladder filter. Experimental results are in a full agreement with theoretical expectations as well as PSpice simulation.