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Serhane R.,Center for Development of Advanced Technologies | Abdelli-Messaci S.,Center for Development of Advanced Technologies | Lafane S.,Center for Development of Advanced Technologies | Khales H.,Center for Development of Advanced Technologies | And 4 more authors.
Applied Surface Science | Year: 2014

Piezoelectric properties of ZnO thin films have been investigated for micro-electro-mechanical systems (MEMS). Wurtzite ZnO structure was prepared on different substrates (Si (1 0 0), Pt (1 1 1)/Ti/SiO2/Si and Al (1 1 1)/SiO2/Si) at different substrate temperatures (from 100 to 500 C) by a pulsed laser deposition (PLD) technique. X-ray diffraction (XRD) characterization showed that the ZnO films were highly c-axis (0 0 2) oriented, which is of interest for various piezoelectric applications. Scanning electron microscopy (SEM) showed evidence of honeycomb-like structure on the surface and columnar structure on the cross-section. In the case of ZnO on Al, ZnO exhibited an amorphous phase at the ZnO/Al interface. The XRD measurements indicated that the substrate temperature of 300 C was the optimum condition to obtain high quality (strongest (0 0 2) peak with the biggest associated grain size) of crystalline ZnO on Pt and on Al and that 400 C was the optimum one on Si. ZnO on Al exhibits smallest rocking curve width than on Pt, leading to better crystalline quality. The ZnO films were used in bulk acoustic wave (BAW) transducer. Electrical measurements of the input impedance and S-Parameters showed evidence of piezoelectric response. The electromechanical coupling coefficient was evaluated as Keff 2 = 5.09%, with a quality factor Qr = 1001.4. © 2013 Elsevier B.V. All rights reserved.

Barra S.,University of Batna | Dendouga A.,Center for Development of Advanced Technologies | Kouda S.,University of ila | Bouguechal N.-E.,University of Batna
Journal of Circuits, Systems and Computers | Year: 2013

The present work analyses the non-ideal effects of pipelined analog-to-digital converters (ADCs), also sometimes referred to as pipeline ADCs, including the non-ideal effects in operational amplifiers (op-amps or OAs), switches and sampling circuits. We study these nonlinear effects in pipelined ADCs built using CMOS technology and switched-capacitor (SC) techniques. The proposed improved model of a pipelined ADC includes most of the non-idealities which affect its performance. This model, simulated using MATLAB, can determine the basic blocks specifications that allow the designer to meet given data converter requirements. © 2013 World Scientific Publishing Company.

Rezoug A.,Center for Development of Advanced Technologies | Hamerlain M.,Center for Development of Advanced Technologies | Tadjine M.,Polytechnic School of Algiers
2012 IEEE International Conference on Robotics and Biomimetics, ROBIO 2012 - Conference Digest | Year: 2012

In this paper, we aim to propose a new robust controller for robot arm driven by pneumatic muscles. Based on sliding mode theory, this control approach consists on the combination of radial based function neural network and type-2 fuzzy logic system. First, the control approach was presented and the stability of the system in closed loop was analyzed using Lyapunov stability theorem. Next, the joints of 2-DOF manipulator robot were approximated as differential linear equations with parameters uncertainties and simulations were given to proof the efficiency and the superiority of this approach compared to radial based function network type-1 fuzzy sliding mode controller used as reference. Last, experimental validation of the proposed approach was presented. © 2012 IEEE.

Mansoul A.,Center for Development of Advanced Technologies | Ghanem F.,Center for Development of Advanced Technologies | Hamid M.R.,University of Technology Malaysia | Trabelsi M.,Polytechnic School of Algiers
IEEE Antennas and Wireless Propagation Letters | Year: 2014

This letter presents a selective frequency-reconfigurable antenna, suitable for cognitive radio applications. The proposed antenna is capable of switching between a wide operating band of 2.63-3.7 GHz and four different subbands, which allows using it for sensing the entire band and then adjusting its bandwidth to select the suitable sub-band and prefilter out the other ones. The antenna is composed of a radiating element in the form of an inverted U fed by a microstrip line on its upper side. In order to achieve a selective frequency reconfiguration, four horizontal slots with integrated p-i-n diode switches are incorporated in the ground plane to act as reconfigurable filter. Some of the switches are used to alter the antenna bandwidth, while the others are employed to shift the operating band by varying the electrical length of the middle slots. To present the work, both simulated and measured results are presented, and a good agreement is achieved. © 2002-2011 IEEE.

Bouchaffra D.,Center for Development of Advanced Technologies
IEEE Transactions on Neural Networks and Learning Systems | Year: 2015

We introduce a novel formalism that performs dimensionality reduction and captures topological features (such as the shape of the observed data) to conduct pattern classification. This mission is achieved by: 1) reducing the dimension of the observed variables through a kernelized radial basis function technique and expressing the latent variables probability distribution in terms of the observed variables; 2) disclosing the data manifold as a 3-D polyhedron via the \alpha -shape constructor and extracting topological features; and 3) classifying a data set using a mixture of multinomial distributions. We have applied our methodology to the problem of age-invariant face recognition. Experimental results obtained demonstrate the efficiency of the proposed methodology named nonlinear topological component analysis when compared with some state-of-the-art approaches. © 2012 IEEE.

Ahmanache A.,Center for Development of Advanced Technologies | Zeraibi N.,University of Boumerdès
Thermal Science | Year: 2013

Numerical study of natural convection heat transfer and fluid flow in cylindrical cavity with hot walls and cold sink is conducted. Calculations are performed in terms of the cavity aspect ratio, the heat exchanger length, and the thermo physical properties expressed via the Prandtl and the Rayleigh numbers. Results are presented in the form of isotherms, streamlines, average Nusselt number, and average bulk temperature for a range of Rayleigh number up to 106. It is observed that Rayleigh number and heat exchanger length influences fluid flow and heat transfer, whereas the cavity aspect ratio has no significant effects.

Himeur Y.,Center for Development of Advanced Technologies | Boukabou A.,Jijel University
AEU - International Journal of Electronics and Communications | Year: 2015

Powerline networks are recently being used for broadband data transmission such as Internet, image and video delivery. Improving the quality of broad transmission over PLC channel is of great importance and an area of current interests. In this paper, we propose a novel estimation and noise mitigation method for power line communication (PLC) systems in impulsive noise environments. For this purpose, an adaptive recursive noise compensator (ARNC) algorithm is proposed, based on an iterative estimation of the impulsive noise, using the signal to impulsive noise power ratio (SINR), and the peak to average power ratio (PAPR) in the time domain after channel equalization and OFDM demodulation. A new clipping/blanking function is introduced to estimate and detect the impulsive bursts. When bit error rate (BER) and mean square error (MSE) are evaluated, the proposed method achieves high performance in an attenuated 15-paths condition. The signal-to-noise (SNR) improvements obtained by the proposed algorithm can achieve 11-18dB under Eb/No=0dB and more than 12dB at BER=10-3 for OFDM signal using quadratic phase-shift keying (QPSK) modulation. © 2015 Elsevier GmbH.

Mansoul A.,Center for Development of Advanced Technologies | Kimouche H.,Ecole Polytechnique - Palaiseau
2013 8th International Workshop on Systems, Signal Processing and Their Applications, WoSSPA 2013 | Year: 2013

A reconfigurable microstrip antenna with switchable frequency is proposed. The proposed antenna has a simple structure, consisting of a square radiating patch and parasitic conductor of rectangular shape. PIN diodes switches are introduced to provide to operate antenna either 2.2 GHz or 2.45 GHz depending on the state of the diodes PIN switches. Very good matching is achieved for the two resonant frequencies. Simulated and measured parameters of the antenna are presented and it is demonstrated that the radiation patterns remain essentially unaffected by the frequency tuning. © 2013 IEEE.

Slimane A.,Center for Development of Advanced Technologies | Belaroussi M.T.,Center for Development of Advanced Technologies | Haddad F.,CNRS Institute Materials Microelectronics nanosciences of Provence | Bourdel S.,CNRS Institute Materials Microelectronics nanosciences of Provence | Barthelemy H.,CNRS Institute Materials Microelectronics nanosciences of Provence
2012 IEEE 10th International New Circuits and Systems Conference, NEWCAS 2012 | Year: 2012

This paper presents a reconfigurable inductor-less CMOS low noise amplifier (LNA) for multi-standard wireless applications. The LNA is designed to address PCS1900, UMTS, WLANb/g and Bluetooth frequency bands. The LNA is based on two cascaded stages. The first stage is a resistive feedback amplifier which achieves a wideband matching in order to address the different application frequency bands while performing a low noise figure. The second stage is a cascode amplifier with an active output LC resonator in order to select the desired bandwidth while achieving high gain and low surface area. The proposed multi-standard LNA, implemented in a 0.13μm CMOS technology achieves more than 26dB gain from 1.8 to 2.4GHz for a noise figure less than 3.4dB. The input and output return losses S11 and S22 are lower than 12dB and 16dB respectively. The LNA consumes 9.6 mA from 1.2V supply voltage and occupies a chip area of 0.165mm 2 including pads. © 2012 IEEE.

Haddad F.,Aix - Marseille University | Rahajandraibe W.,Aix - Marseille University | Slimane A.,Center for Development of Advanced Technologies
Proceedings - IEEE International Symposium on Circuits and Systems | Year: 2015

This article presents the design and implementation of a multi-stage radio-frequency (RF) passive polyphase filter (PPF). The layout parasitics and mismatch which deteriorate significantly the RF filter performance are analyzed and modeled. To reduce this parasitic degradation, a novel optimal layout technique is proposed. It is based on reproducing the same optimized PPF stage layout for the different stages while the desired bandwidth is ensured due to an optimal sizing of the inter-stages connections. This approach has been validated with on chip measurements. Using the proposed techniques more than 55 dB of image rejection over the [1.5; 3.3] GHz bandwidth is demonstrated while achieving zero power consumption and small silicon area in 130nm CMOS technology. © 2015 IEEE.

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