Versatile MIMO voltage-mode OTA-C universal biquadratic filter

This paper presents a new versatile voltage-mode universal filter with multiple-input multiple-output (MIMO) based on single-ended operational transconductance amplifiers (OTAs). The proposed circuit can realize a two-input, four-output biquad filter and a three-input, single-output biquad filter without changing the circuit topology. The natural frequency and the quality factor can be set orthogonally by adjusting the circuit components. The natural frequency can also be controlled electronically by adjusting the bias currents. The simulation results are performed to confirm the presented theory.