Electronically Tunable Multifunction Transadmittance-Mode Fractional-Order Filter

In this paper a multifunction transadmittance-mode fractional-order filter is proposed for the very first time. The proposed structure provides fractional-order low-pass filter, fractional-order high-pass filter and fractional-order all-pass filter. It uses two operational transconductance amplifier and one fractional capacitor (FC). The FC is realized using the twelfth-order continued fraction expansion-based RC ladder. Functional verification of proposed fractional-order filter is verified through PSPICE using 180-nm CMOS technology model parameters. The transfer functions sensitivities' with respect to various circuit parameters are examined through simulations. The effect of parameter variation on filter responses is studied using Monte Carlo analysis. Furthermore, the proposed filter possess electronic tunability through bias currents. Moreover, the circuit is tested experimentally using discrete components to realize the fractional-order capacitor showing great matching with the theoretical data.