MOS realizations of fractional-order elements

The exploitation of fractional calculus in engineering applications requires the utilization of fractional-order elements. As there is no immediate access to such type of elements, emulators that proportionally imitate their behavior are developed. The realization of emulators of fractional-order elements is based on the approximation of their impedance function. Subsequently, an advantageous option for the circuit implementation of the obtained, approximated impedance function is MOS transistor-based configurations, as they provide a dynamic system with electronically adjustable parameters. In this chapter, two different MOS transistor-based realization techniques are presented: an electronically controlled RC network-based realization and a fractional-order integrator/differentiator-based realization. Considering the second technique as a more general and applicable option, some practical aspects are discussed with appropriate solutions being proposed, in order to improve the functionality of the emulator. © 2022 Elsevier Inc. All rights reserved.