Current-programmable Universal Biquad Filter Based on Modified Current Differencing Transconductance Amplifier

This paper presents a new current programmable active element called Modified Current Differencing Transconductance Amplifier (MCDTA). The parameters of the circuit - input resistance and transconductance - can be tuned by control currents. The circuit with several external components - diodes and grounded capacitors - makes it possible to build basic analog circuits: first order and second order tunable active filters, rectifiers, peak detectors and others. This paper discusses a universal biquad filter based on the MCDTA with different tuning capabilities. The simulation results show that it can be used as a part of a programmable analog signal processing system.