Adjustable Multiphase Sinusoidal Oscillator with Fractional–Order Elements

Abstract

This paper presents a fractional–order multiphase oscillator with adjustable FO (Frequency of Oscillation). The oscillator utilizes the following components: CCTA (Current Conveyor Transconductance Amplifier), OTA (Operational Transconductance Amplifier), auxiliary OTRA (Operational Transresistance Amplifier), two FOC (Fractional–Order Capacitors) and auxiliary resistors. The proposed structure provides three voltage outputs and their inverted variants for three selected values of $\alpha =0.3$, 0.5, and 0.8 of FOC. The FO is tuned by changing the values of the transconductances of the OTA and CCTA. The features of the presented circuit were verified by PSpice simulations with behavioural models of the active elements. Analysis of the dependence of the values of the transconductances on values of $\alpha$ and frequency is provided. A THD (Total Harmonic Distortion) and parasitic analysis of the circuit was also made.