In this work, a generic impedance modeling technique is proposed. The technique is able to identify a circuit model that is most suitable for fitting measured impedance magnitude data using a genetic algorithm solver as well as the optimum circuit model parameters. Experimentally measured and simulated data sets with different noise levels are used to validate the technique. © 2020 Elsevier GmbH

A dynamic model of Photo-Voltaic (PV) solar module is important when it is utilized in conjunction with switching circuits and in grid connected applications. In this paper, a fractional-order dynamical model of a PV source is introduced. The model includes both a fractional series inductor and a parallel capacitor which are in general of two different orders allowing for extra degrees of modeling freedom. An expression for the load current is derived and the step response is investigated for different orders. It is found that the nature of the connections has a dominant effect on the response

Recently, the triple-lobe behavior is found in the I-V characteristics of some memristive devices generating another non-zero pinchoff point. In this paper, a flux-controlled memristive model is developed to generate the triple-lobe behavior (double pinchoff points) based on a fractional second-order model. The conditions for observing triple lobes are derived besides the coordinates of the pinchoff points. Different scenarios have been considered by changing the model parameters and fractional order. Furthermore, the minimum and maximum achievable conductances are analyzed and mathematically

In this paper, a general analysis of the fractional order operational transresistance amplifiers (OTRA) based oscillator is presented and validated through eight different circuits which represent two classifications according to the number of OTRAs. The general analytical formulas of the oscillation frequency, condition as well as the phase difference are illustrated for each case and summarized in tables. One of the advantages of the fractional-order circuit is the extra degrees of freedom added from the fractional-order parameters. Moreover different special cases {α = β ≢ 1, β ≢ α = 1, α ≢

A novel resistorless topology for implementing fractional-order capacitor emulators, based on the employment of Operational Transconductance Amplifiers (OTAs) as active elements, is presented in this paper. The benefits of this topology are its simplicity in terms of component count, compared to other existing topologies in the literature, in addition to its electronic tunability. The performance of the presented topology is evaluated using Cadence and the 0.35 μm CMOS process Design Kit from Austria Mikro Systeme. Experimental results using commercial OTA chips are also provided, where the

A new approximation method of the fractional-order Laplacian operator sα is introduced. The approximation is based on a weighted sum of first-order filter sections and its analytical proof is given. The optimal high-pass filter section parameters that cover six frequency decades are obtained using the flower pollination algorithm while the effect of the number of filter sections on the accuracy of the approximation is investigated. Approximations of fractional-order capacitors of orders α =0.5 and α =0.7 synthesized in Foster-II form are given as a validating example. Further, an active

Recently, multi-phase oscillator design witnesses a lot of progress in communication especially phase shift keying based systems. Yet, there is a lack in design multi-phase oscillator with different fractional phase shifts. Thus, in this paper, a new technique to design and analyze a multi-phase oscillator is proposed. The proposed procedure is built based on the fractional-order elements or constant phase elements in order to generate equal or different phase shifts. The general characteristics equation for any oscillator is studied to derive expressions for the oscillation conditions and

This paper presents a study of fractional order oscillator design based on a matrix. The presented oscillator consists of a general two port network and three impedances. Only two port with single element in its transmission matrix is discussed which gives four possible networks. Different combinations for one element have been investigated. The impedances associated with the studied networks are series or parallel connection of resistors in addition to fractional order capacitors. The characteristic equation, oscillation frequency and condition for each combination are introduced. Numerical

Most of electric circuits can be viewed as a two port network with two terminals defined as input and output ports. In this paper, two different concepts are combined together which are the two port network concept and the fractional calculus to design a general fractional order two port network with equal order. An oscillator case study with three impedances structure has been presented. The three impedances are two equal order fractional capacitors and a resistor. Two different two port network are studied which are Op-amp based circuit and nonideal gyrator circuit. The general oscillation

This paper is a step forward to generalize the fundamentals of the conventional RC and RL circuits in fractional-order sense. The effect of fractional orders is the key factor for extra freedom, more flexibility, and novelty. The conditions for RC and RL circuits to act as pure imaginary impedances are derived, which are unrealizable in the conventional case. In addition, the sensitivity analyses of the magnitude and phase response with respect to all parameters showing the locations of these critical values are discussed. A qualitative revision for the fractional RC and RL circuits in the