This study presents a new active building block for analog signal processing applications, namely fully differential current conveyor transconductance amplifier. The proposed circuit is realized using differential difference current conveyors and transconductance amplifiers. Unlike, previous building blocks, both fully differential input and electronic tuning capability can be obtained into a single new device. The proposed building block is used to realize a universal biquadratic filter as an example application. PSPICE simulation results using 0.5 mu m CMOS technology from MIETEC are used to confirm the presented building block. The simulation results express that the proposed active building block can be used to realize analog signal processing circuits.