Bassam Harb

Al Ain University · Faculty of Engineering

span lang="EN-US">It is known that a shunted nonlinear resistive-capacitive-inductance Josephson-junction (RCLSJ) model has a chaotic attractor. This attractor is created as a result of Hopf bifurcation that occurs when a certain direct current (DC) applied to one of the junction terminals. This chaotic attractor prevents the system from reaching t...

In this paper, the modern nonlinear theory is applied to a third order phase locked loop (PLL) with a feedback time delay. Due to this delay, different behaviors that are not accounted for in a conventional PLL model are identified, namely, oscillatory instability, periodic doubling and chaos. Firstly, a Pade approximation is used to model the time...

In this paper, a reconfigurable patch antenna with Circular Polarization (CP) diversity with theoretical discussion and verification is proposed for fifth generation (5G) of mobile communication systems. The proposed antenna contains two PIN diodes, which are correctly placed on the ground plane to obtain polarization diversity. By switching betwee...

Analysis of bifurcation of second-order analog phase locked loop (PLL) with tanlock and sawtooth phase detectors is investigated. Both qualitative and quantitative analyses are carried out. Qualitatively, the basin boundaries of the attractors were constructed by plotting the stable and the unstable manifolds of the system. The basin boundaries sho...

An error-function analytical expression describing compositional grading in a 850 nm AlGaAs/GaAs top-emitting oxide confined vertical cavity surface emitting laser has been derived. Results are presented showing that the optical properties of the considered device utilizing the proposed error-function compositional scheme are superior over other gr...

In this paper, we present a novel guard-band-aware channel assignment mechanism that attempts at maximization the achieved network throughput by improving spectrum utilization. Unlike most of previously proposed GB-aware channel assignment algorithms that perform the assignment sequentially, the proposed mechanism performs the channel and power ass...

The adjacent channel interference (ACI) resulting from imperfect filtering can severely degrade the performance of any wireless communication system. Despite this fact, most of previously proposed medium access control (MAC) protocols for cognitive radio networks (CRNs) were designed while ignoring the effects of ACI (assuming ideal filtering). The...

This paper presents a curriculum design approach for a Masters program in Telecommunications Management based on demand data obtained from surveying the needs of the potential students of the proposed program. Through online surveys disseminated at telecom companies in Jordan, it was possible to measure the demand for such a program and to determin...

The pull-in range of phase locked loop (PLL) is a key parameter for evaluating the performance of the PLL circuit. It is defined as the maximum detuning frequency range where the loop locks. Different methods have been proposed for computing the pull-in range of phase locked loops in the absence of time delay. In this paper, the effect of time dela...

In this paper, a combined Fractal and Wavelet (CFW) compression algorithm targeting x-ray angiogram images is proposed. Initially, the image is decomposed using wavelet transform. The smoothness of the low frequency part of the image appears as an approximation image with higher self similarities, therefore, it is coded using a fractal coding techn...

This article presents the methodology and results of the curriculum review of the Masters of Science programme inWireless Communications offered by the Telecommunications Engineering Department at Yarmouk University in Jordan. The review is based on expert opinion collected through questionnaires and meetings about the programme and focuses on two...

In this paper, we have discussed the application of new nonlinear recursive controllers on Josephson junction (JJ) chaotic systems. Controlling bifurcation as well as chaos has been rapidly advancing in the last decade. Thus, emphasis has been placed on control design techniques which result in prescribed nonlinear performance dynamics for practica...

Traditional tools used in education, are increasingly more complemented with computer based Instructional software. This paper presents an interactive approach for teaching the Digital Signal Processing (DSP) course. The effect of the Instructional Software on the achievement of students in the subject of DSP is compared to the conventional teachin...

A new hybrid two-stage electrocardiogram (ECG) signal compression method based on the modified discrete cosine transform (MDCT) and discrete wavelet transform (DWT) is proposed. The ECG signal is partitioned into blocks and the MDCT is applied to each block to decorrelate the spectral information. Then, the DWT is applied to the resulting MDCT coef...

Previous study showed that a third-order phase locked loop (PLL) with sinusoidal phase detector characteristics experienced a Hopf bifurcation point as well as chaotic behavior. As a result, this behavior drives the PLL to the out-of-lock (unstable) state. The analysis was based on a modern nonlinear theory such as bifurcation and chaos. The main g...

In this paper, a nonlinear backstepping controller has been designed to control bifurcation as well as incipient chaos that has been experienced in the RCLSJ (shunted nonlinear resistive-capacitive-inductance) Josephson-Junction. The results show that the system, without controller, has a dangerous Hopf bifurcation point that lead to chaotic behavi...

In this paper, we demonstrate by simulation that chaos intermittency is observed in mutually coupled third order PLL with sinusoidal phase detector characteristics. This system is represented by seven-dimensional nonlinear nonautonomous differential equation. For a coupling factor ζ = 0.8, we found a type of intermittency arise through increasing t...

Previous study showed that a third-order phase-locked loop (PLL) with sinusoidal phase detector characteristics experienced a Hopf bifurcation point as well as chaotic behavior. As a result, this behavior drives the PLL to the out-of-lock (unstable) state. The analysis was based on a modern nonlinear theory such as bifurcation and chaos. The main g...

The chaos induced in a new type of phase locked loop (PLL) having a second-order loop filter is investigated. The system under consideration is modeled as a third-order autonomous system with sinusoidal phase detector characteristics. The modern of nonlinear theory such as bifurcation and chaos is applied to a third-order of PLL. A method is develo...

The pull-in range (ωp) of a phase-locked loop (PLL) is defined as the maximum value of loop detuning ω0s for which pull-in occurs from anywhere on the PLL's phase plane. That is, pull-in is guaranteed from anywhere on the phase plane if ω0s < ωp. Simple approximation is available for computing ωp for the high gain PLL where saddle-node bifurcation...

In this paper, a Galerkin-based method is applied to a single machine infinite busbar (SMIB) power system. The method computes the separatrix cycle and the exact values for the input mechanical power at which a limit cycle bifurcates from the separatrix cycle. The first part of the algorithm approximates the limit cycle by a truncated Fourier serie...

The chaos induced in a new type of phase locked loop (PLL) having a second-order loop filter is investigated. The system under consideration is modeled as a third-order autonomous system with sinusoidal phase detector characteristics. The modern nonlinear theory such as bifurcation and chaos is applied to a third-order PLL. A method is developed to...

This paper presents a new active noise control system to cancel the unwanted periodic noise signal that is presented in industrial settings. An adaptive technique for active control of periodic noise of unknown frequency is presented. A technique based on LMS is used for updating the harmonic controller gains with an efficient recursive technique t...

The pull-in range Ωp of a second-order, Type I phase-locked loop (PLL) is defined as the maximum value of loop detuning ωos for which pull-in occurs from anywhere on the PLL's phase plane. That is, pull-in is guaranteed from anywhere on the phase plane if |ωos| < Ωp. Simple approximations are available for computing Ωp. The concept is expanded here...

A definition is given for the half-plane pull-in range Ω₂ of a second-order PLL with imperfect integrator. A formula for approximating Ω₂ is not available. However, an iterative computational algorithm is presented for computing Ω ₂, and it is applied to a simple example

A Galerkin-based algorithm is used to analyze the bifurcation responsible for breaking the false lock state in a second-order, Type I PLL. The algorithm has two major components. The first deals with approximating the limit cycle associated with the PLL's false lock state by a number of harmonics. The amplitudes of these harmonics are formulated as...

Thesis (Ph. D.)--University of Alabama in Huntsville, 1994. Typescript (photocopy). Includes bibliographical references (p. 137-139).