Dual Mode Biquadratic Fractional Order Filter Using VDTA

This paper presents a novel configuration for a biquadratic filter employing a single voltage differencing transconductance amplifier (VDTA) and fractional order capacitors. The proposed filter leverages the flexibility and tunability of VDTAs in conjunction with fractional-order components to achieve enhanced performance and control over frequency characteristics. Fractional capacitance elements, modelled using Continued Fraction Expansion (CFE), are implemented to enable the realization of fractional-order impedance, allowing for smoother transitions and improved selectivity compared to conventional integer-order filters. The proposed design is validated through LT SPICE simulations utilizing TSMC CMOS technology. Key parameters such as fractional order and cutoff frequency are studied to demonstrate the adaptability of the proposed structure.