Recently, many reactance-less memristive relaxation oscillators were introduced, where the charging and discharging processes depend on memristors. In this paper, we investigate the power dissipation in different memristor based relaxation oscillators. General expressions for these memristive circuits as well as the power dissipation formulas for three different topologies are derived analytically. In addition, general expressions for the maximum and minimum power dissipation are calculated. Finally, the calculated expressions are verified using PSPICE simulations showing very good matching.

Recently, the applications of memristors have spread into many fields and especially in the circuit theory. Many models have been proposed for the HP-memristor based on the window functions. In this paper, we introduce a complete mathematical analysis of the controlled reactance-less oscillator for two different window functions of Joglekar's model (linear and nonlinear dopant drift) to discuss the effect of changing the window function on the oscillator's behavior. The generalized necessary and sufficient conditions based on the circuit elements and control voltages for both the linear and

This paper introduces a mathematical model of an ideally threshold compensated rectifier for RF energy harvesting. The ideally compensation arrangement has been exploited to improve the rectifier's performance and overcome the limitation of rectifier's sensitivity which mainly depends on the threshold voltage of the rectifying devices (transistors). The model considers the conduction angle and the reverse current in deriving closed form analytical expressions for output dc voltage and efficiency. Using a 65-nm low leakage CMOS process with low-threshold transistors, 900-MHz multi-stages

We propose a mathematical system capable of exhibiting chaos with a chaotic attractor which is odd symmetrical in the x − y phase plane but even symmetrical in the x − z and y − z phase planes respectively. A hardware implementation of the system is done on a digital FPGA platform for verification. The system is also attractive in the sense that (i) its dynamics are single-parameter controlled and (ii) it inherently generates two chaotic clock signals. As an application, an FPGA design methodology using this oscillator for speech encryption is demonstrated. The security of the proposed

In this study, we report the electrical response of two sets of solid-state fractional-order electrochemical capacitors for which the low-frequency impedance phase angle can be tuned from - 69 ° to - 7 °. The configuration makes use of a gel electrolyte in which carbonaceous additives (graphite or reduced graphene oxide) are dispersed at different proportions. Such a disordered electrolyte structure results in subdiffusive charge transport and thus a frequency dispersive capacitive-resistive behavior typical of a constant phase element, which can be useful for both frequency applications and

To implement an approximation of the fractional order Laplacian operator s α as a weighted sum of high pass filter sections, it is essential to extract the cutoff frequencies and filter gains of each section in order to achieve the lowest error possible. Therefore, in this work, five meta-heuristic optimization algorithms are tested in this problem based on a weighted sum objective function. The employed algorithms include the: ant-lion optimizer, cuckoo search algorithm, flower pollination algorithm, whale optimizer, and multi-verse algorithm. A comparison is carried out between the results

Shared by various physical, chemical, and biological systems, fractional-order dynamics assert that the present state of a system is the result of not only the applied stimulus but also its past history. Consequently, in fractional-order systems, there exists a system-specific, input-dependent memory kernel. In this study, we demonstrate experimentally the existence of a memory effect in electric double-layer capacitors which are known to exhibit a fractional-order behavior through their non-single, distributed internal time constants. This is performed by showing variance in the discharge

Random bit generators (RBGs) in today's digital information and communication systems employ a high rate physical entropy sources such as electronic, photonic, or thermal time series signals. However, the proper functioning of such physical systems is bound by specific constrains that make them in some cases weak and susceptible to external attacks. In this study, we show that the electrical current time series of contact glow discharge electrolysis, which is a dc voltage-powered micro-plasma in liquids, can be used for generating random bit sequences in a wide range of high dc voltages. The

Recently, double pinch-off points have been discovered in some memristive devices where the I-V hysteresis curve intersects in two points generating triple lobes. This paper investigates a fractional-order flux-controlled mathematical model which is able to develop the multiple pinch-off points or multiple lobes. The conditions for observing double pinch-off points (triple lobes) are derived in addition to the locations of the pinch-off points which do not appear in the integer domain. Also, expressions for maximum and minimum conductance are derived. Finally, a floating fractional flux

Mathematical Techniques of Fractional Order Systems illustrates advances in linear and nonlinear fractional-order systems relating to many interdisciplinary applications, including biomedical, control, circuits, electromagnetics and security. The book covers the mathematical background and literature survey of fractional-order calculus and generalized fractional-order circuit theorems from different perspectives in design, analysis and realizations, nonlinear fractional-order circuits and systems, the fractional-order memristive circuits and systems in design, analysis, emulators, simulation