Voltage-mode biquadratic filters using single DDCCTA

This paper presents two voltage-mode universal biquadratic filters based on a single differential difference current conveyor transconductance amplifier (DDCCTA). Each of the proposed circuits comprises a single DDCCTA combined with passive components that can realize lowpass (LP), highpass (HP), bandpass (BP), bandstop (BS), and allpass (AP) filtering responses from the same configuration. The first proposed configuration can be used as either a high-input impedance single-input four-output multifunction filter or three-input four-output universal filter. The second proposed circuit with single-input five-output is slightly modified from the first proposed configuration that can simultaneously realize LP, HP, BP, BS, and AP filtering responses. The proposed circuits enjoy the features of orthogonal tunable of resonance angular frequency and quality factor, only using grounded capacitors, and low active and passive sensitivities. Experimental and H-Spice simulation results are given to confirm theoretical analyses.