This paper presents a generalized family of fractional-order oscillators based on single CFOA and RC network. Five RC networks are investigated with their general state matrix, and design equations. The general oscillation frequency, condition and the phase difference between the oscillatory outputs are introduced in terms of the fractional order parameters. They add extra degrees of freedom which in turn increase the design flexibility and controllability that is proved numerically. Spice simulations are introduced to validate the theoretical findings. © 2017 IEEE.
Two topologies of fractional-order oscillators based on CFOA and RC networks
This paper presents two general topologies of fractional order oscillators. They employ Current Feedback Op-Amp (CFOA) and RC networks. Two RC networks are investigated for each presented topology. The general oscillation frequency, condition and the phase difference between the oscillatory outputs are investigated in terms of the fractional order parameters. Numerical simulations and P-Spice simulation results are provided for some cases to validate the theoretical findings. The fractional order parameters increase the design flexibility and controllability which is proved by the provided experimental results. © 2018 IEEE.
Dynamics of fractional and double-humped logistic maps versus the conventional one
This paper presents the dynamic analysis of two discrete logistic chaotic maps versus the conventional map. The first map is the fractional logistic map with the extra degrees of freedom provided by the added number of variables. It has two more variables over the conventional one. The second map is the double-humped logistic map. It is a fourth-order map which increases the non-linearity over the conventional one. The dynamics of the three maps are discussed in details, including mathematical derivations of fixed points, stability analysis, bifurcation diagrams and the study of their chaotic regions. The chaotic behavior of the three maps, is investigated using the Maximum Lyapunov exponent (MLE). © 2017 IEEE.
Frational Order Inverse Filters Based on CCII Family
This paper proposes two generalized topologies of fractional order inverse filters (FOIF). All possible realizations of each topology are investigated using the second generation current conveyor (CCII) family. Inverse fractional highpass (IFHPF), inverse fractional bandpass (IFBPF), and inverse fractional lowpass (IFLPF) filters are realized using the same topology based on the generalized admittances. Numerical and P-Spice simulation results are presented for selected cases to approve the theoretical findings. The fractional order parameters increase the design flexibility and controllability which is validated experimentally. © 2019 IEEE.
Image encryption in the fractional-order domain
This paper presents a new image encryption scheme based on the fractional-order Lorenz system which gives more degrees of freedom in key generation. In the modified fractional-order system, the key length is doubled using the three fractional-orde r parameters beside the three initial conditions, which makes it invulnerable to brute-force attacks. In addition, using a very simple algorithm, based on pixel confusion only, strongly encrypted images are produced. Such an algorithm can be used in real time applications. To evaluate the algorithm and analyze the encryption results, a standard image is used. A comparison of the colored correlation coefficients (horizontal, vertical, diagonal) for different cases with respect to a fractional-order parameter and another system parameter are introduced. Moreover, the encrypted image shows high sensitivity to the fractional-order key, which appears from the wrong decryption with 0.1% change of the fractional-order parameter. © 2012 IEEE.
Tunable fractional-order band-pass filter of order 2?
In this work, a novel implementation of a tunable fractional-order bandpass filter of order 2? is proposed. The transfer function of the presented filter is approximated using the second-order Continued Fraction Expansion (CFE) approximation technique. The filter transfer function is realized using the Inverse Follow the Leader Feedback (IFLF) structure. The Operational Transconductance Amplifiers (OTAs) are used to implement the filter circuit. Furthermore, the proposed filter is tunable by varying the value of only one bias current, which adjust the value of ?. The simulations are performed using Matlab and Cadence software with UMC 0.13? m CMOS technology. © 2019 IEEE.
A Universal Fractional-Order Memelement Emulation Circuit
This paper proposes a current-/voltage-controlled universal emulator that can realize any fractional-order memelements (FOME). The proposed emulator consists of second-generation current conveyors (CCII) block, two switches, and a multiplier/divider block. The first switch controls the emulator mode (voltage or current), while, the other controls the type of the emulated FOME. The influence of the fractional-order capacitor (FOC) on the pinched hysteresis loop (PHL) area, is discussed which increases the controllability on the double loop area and the working frequency range. Numerical and PSPICE simulations are presented for selected cases to prove the theoretical findings. © 2019 IEEE.
On Series Connections of Fractional-Order Elements and Memristive Elements
This paper proposes a current-controlled fractional-order memristor emulator based on one active building block. The emulator consists of a multiplication mode current conveyor (MMCC) block with three passive elements. Additionally, the series connection of fractional-order inductor (FOI) and fractional-order capacitor (FOC) with memristive elements in the i-v plane is demonstrated numerically for different cases. Changing the order of the FOC or FOI and its effect on the pinched hysteresis loop area are investigated, which improve the controllability of the double loop area, the location of the pinched point, and the operating frequency range. Numerical, PSPICE simulation results, and experimental verification are investigated for different cases to approve the theoretical findings. Moreover, a sensitivity analysis using Monte Carlo simulations for the tolerance of the discrete components of the memristor emulator is investigated. © 2020 IEEE.
Toward Portable Bio-impedance devices
Bio-impedance measurement has been used as an indicator for specific physical and chemical changes in food products, fruits and vegetables, cancer detection and other applications. In this paper, a portable wireless bio-impedance measurement embedded system, based on the AD5933 chip, is introduced. The system is calibrated using a parallel RC network and the industry standard electrochemical station BioLogic SP-150. The module can be used in many impedance measuring applications. © 2019 IEEE.
Impedance matching through a single passive fractional element
For the first time, a generalized admittance Smith chart theory is introduced to represent fractional order circuit elements. The principles of fractional order matching circuits are described. We show that for fractional order ? < 1, a single parallel fractional element can match a wider range of load impedances as compared to its series counterpart. Several matching examples demonstrate the versatility of fractional order series and parallel element matching as compared to the conventional approach. © 2012 IEEE.