Prof. Ahmed Radwan

This paper discusses the use of the memristor in one of the most important modulation techniques in communication field namely the pulse-width modulation. A fundamental two designs for memristor-based lead and trail PWM are discussed with mathematical analysis and PSPICE simulation results which show a great matching with the analytical formulation. Moreover, a third design which combine those two

This paper summarizes the symmetric image encryption results of 27 different algorithms, which include substitution-only, permutation-only or both phases. The cores of these algorithms are based on several discrete chaotic maps (Arnold's cat map and a combination of three generalized maps), one continuous chaotic system (Lorenz) and two non-chaotic generators (fractals and chess-based algorithms)

This paper introduces data converter circuit based on memristors. A proposed Digital to Analog Converter (DAC) circuit based on non-overlapped input signals, which is suitable for common source connected transistors. Analytical formulas are introduced to relate the digital input with the analog output including the transistors dimension. In addition, PSpice simulations are performed to validate

Arithmetic Logic Unit (ALU) is the most important component of processors. All arithmetic and logical computations are performed inside the ALU. This paper presents the design and the implementation of the ALU. The design is based on Approximated Precision Shader and Look-Up Table (LUT) multiplier. The lookup table, Wallace tree, and Carry Look-ahead Adder (CLA) are used in combination to speed up

Characterizing and modeling electrical energy storage devices is essential for their proper integration in larger systems. However, basic circuit elements, i.e. resistors, inductors, and capacitors, are not well-suited to explain their complex frequency-dependent behaviors. Instead, fractional-order models, which are based on non-integer-order differential equations in the time-domain and include

Chaos is described as a unstable dynamic behavior with dependence on initial conditions. The control and synchronization of chaotic systems requires the knowledge of parameters in advance. Recently researcher's has been shifted from integer order chaotic system to fraction order chaotic system. In this work, based on the stability theory of integer-order linear systems and Lyapunov stability

This paper studies the famous Fitzhugh-Nagumo and Izhikevich neuron models in the fractional-order domain. Generalization of the integer models into the fractional-order domain providing a wider scope understanding of the neuron systems. The fractional Fitzhugh-Nagumo circuit model and the state space equations are introduced. Different fractional orders are studied as an example. Numerical

This paper presents a study for general fractional order oscillator based on two port network where two topologies of oscillator structure with two impedances are discussed. The two impedances are chosen to be fractional elements which give four combinations for each topology. The general oscillation frequency, condition and the phase difference between the two oscillatory outputs are deduced in

In this paper, the effect of non-zero initial condition on the time domain responses of fractional-order systems using Caputo and Riemann-Liouville (RL) fractional definitions are discussed. Analytical formulas were derived for the step and square wave responses of fractional-order RCα circuit under RL and Caputo operators for non-zero initial condition. Moreover, a simulation scheme for