Browsing by Author "Aksas, R."

Now showing 1 - 9 of 9

A 2.3-14 GHz UWB planar octagonal antenna with modified ground plane
(Wiley Periodicals, 2013) Bitchikh, M.; Aksas, R.; Azrar, Arab; Kimouche, H.
Application of the FCEL method to a microstrip disk antenna with a parasitic director
(2009) Berbar, T. B.; Azrar, Arab; Zerguerras, A.; Aksas, R.
The method of finite coupled elementary lines (FCEL) is used in the analysis of a microstrip disk antenna with a larger parasitic director. A closed form expression of the effective radius for the used structure is proposed. The obtained numerical results are compared with published measurements and good agreement is noticed
Bandwidth improvement of a single-stage distributed amplifier
(2010) Amrani, F.; Trabelsi, M.; Aksas, R.; Azrar, Arab
The article discusses the use of bandwidth to improve single-stage distributed amplifier with the use of a Chebyshev polynomial to express the transducer power gain. It states that the conventional distributed amplifiers are formed by artificial transmissions and conventional single-stage distributed amplifier. In addition, the metal semiconductor field effect transistor has gate capacitance of the transistor to improve the bandwidth of the single-stage distributed amplifier
Characterization of the polarization in the spun fibers
(2009) Cherbi, L.; Azrar, Arab; Mehenni, M.; Aksas, R.
The polarization mode dispersion (PMD) is a difficult phenomenon to compensate in the optical fiber. Its reduction can be achieved by the spinning process that provokes the rotation of the birefringence axes of the fiber inciting a coupling of its modes that is controlled at the time of its manufacture. In this work, the Jones Matrix Eigen-Analysis method (JME) is used to characterize the spun fibers to evaluate their PMD and to prove that it is distinctly lower than the standards fibers PMD. Furthermore, the differential group delays (DGD) of spun fibers is determined using the photon counting optical time-domain reflectometry (C-OTDR) method. The obtained results are compared with those found in the JME method. It is noted that the two methods yield practically identical values. The determination of the beat length and the spin period of spun fibers are carried out using the polarization-sensitive optical frequency-domain reflectometer (POFDR
Design and optimization of a CPW-fed tri-band patch antenna using genetic algorithms
(Applied Computational Electromagnetics Society (ACES), 2015) Fertas, K.; Kimouche, H.; Challal, Mouloud; Aksas, Hammouche; Aksas, R.; Azrar, Arab
Erratum : new UWB antenna design for wireless communications
(Wiley, 2012) Bitchikh, M.; Aksas, R.; Kimouche, H.; Azrar, Arab
New UWB antenna design for wireless communications
(2012) Bithikh, M.; Aksas, R.; Kimouche, H.; Azrar, A.
The presented work in this article concerns a new ultra-wideband antenna design with an octagonal configuration and reduced dimensions. Different prototypes have been simulated and implemented in the form of monopoles. These prototypes have shown an admissible agreement between simulations and measurements and ultra-wide bands running from 3.1 to 14 GHz for wireless applications. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:692–697, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26666
Novel design of miniaturized broad stopband bandpass filter using defected ground structure
(International Journal of Microwave and Optical Technology, 2014) Challal, Mouloud; Dehmas, Mokrane; Azrar, A.; Aksas, R.; Trabelsi, M.
Wide stopband microstrip bandpass filter based on a compact slotted ground structure
(Polish Academy of Sciences, 2015) Challal, Mouloud; Dehmas, Mokrane; Azrar, A.; Aksas, R.; Trabelsi, M.
A new concept for implementing a bandpass filter by employing a discontinuity in the feed microstrip line in the upper layer and modified dumbbell-shaped slots etched in the ground plane is proposed. The effect of the slot area on the bandpass filter performance is examined. The proposed bandpass filter showed wide stopband and low insertion loss. To further verify the new concept, the structure is implemented and the measurement results are found to be in good agreement with the simulation ones. The proposed structure can be used in various microwave circuits