Publications Internationales

Permanent URI for this collectionhttps://dspace.univ-boumerdes.dz/handle/123456789/13

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Author: search.filters.author.Challal, MouloudHas files: Yes

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Now showing 1 - 10 of 27
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    Compact CPW-fed Antenna with Controllable WLAN Band-rejection for Microwave Imaging
    (Advanced Electromagnetics, 2024) Mokhtari, Mokhtar; Oussaid, Rachid; Mansoul, Ali; Challal, Mouloud
    This work presents the design and experimental validation of a compact frequency-reconfigurable coplanar waveguide (CPW)-fed ultra-wideband (UWB) antenna for application in microwave imaging systems with a capability to switch between UWB modes, with and without WLAN band-notched features. The suggested topology and design process are used to achieve an enhancement in the bandwidth using T-shaped slots between the feedline and the ground plane of the antenna, whereas the WLAN band is rejected using an open loop resonator (OLR) placed on the antenna backside. Switching between UWB with and without WLAN band-notched modes is performed using a single PIN diode. The simulation results corroborate well with the experimental data and clearly show an interesting frequency reconfigurable behavior for use in microwave imaging applications. The antenna performance simulation and analysis model is presented for breast tumor detection.
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    A Compact Slot-Antenna with Tunable-Frequency for WLAN,WiMAX, LTE, and X-Band Applications
    (2020) Fertas, Fouad; Challal, Mouloud; Fertas, Khelil
    In this paper, a new monopole compact antenna with tunable frequency fed by a coplanarwaveguide (CPW) for WiMAX, WLAN, LTE bands, and X-band satellite communication system ispresented. This is achieved by adequate combination of a new radiating patch element along with slotsand switches. The simulation and measurement results show that depending on ON/OFF states, theproposed reconfigurable antenna, printed on an FR4 substrate, can operate in four applicable frequencybands, i.e., [2.37–2.75 GHz], [3.15–4.08 GHz], [4.48–5.92 GHz], and [6.69–8.31 GHz]. Very interestingresults for the reflection coefficient, current distribution, and radiation pattern of the antenna arepresented and discussed. The measured results are in good agreement with the simulated ones
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    Miniaturized Concentric Hexagonal Fractal Rings Based Monopole Antenna for WLAN/WiMAX Application
    (Scimago Journal & Country Rank, 2019) Djafri, Kahina; Challal, Mouloud; AKSAS, Rabia; Mouhouche, Faiza; Dehmas, Mokrane
    In this paper a new antenna design technique is introduced in order to achieve tri-band operation as well as antenna miniaturization. The technique consists of using two concentric first-iterative hexagonal rings connected to each other as a radiating patch fed with a Y-shaped micro-strip line. The proposed antenna operates at three fre-quency bands to cover 2.4/5.8 GHz WLAN bands and 3.5/5.5 GHz WiMAX bands applications. The numerical analysis and simulation are carried out with CST MWS. The measured return losses of the proposed antenna show good performance and good agreement with the simulated ones. Consequently the proposed antenna with compact size of 9.7 mm x 17 mm x 1.63 mm is well suited for wire-less applications.
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    A Compact Dual-Band Planar Monopole AntennaUsing Fractal Rings and A Y-Shaped FeedingTransmission Line
    (DE GRUYTER, 2018) Djafri, Kahina; Challal, Mouloud; Romeu, Jordi
    This paper presents a novel design approach ofa compact dual-band monopole antenna with an overallsize of 18.9x13x1.6mm3. The proposed antenna is com-posed of a fractal ring shaped patch fed by a Y-shapedtransmission line on the top side of the substrate and asecond fractal ring along with a U-shaped ground planeon the bottom side. The second fractal ring, identical tothe radiating ring, is loaded and a rectangular slot isetched at the top side of the ground plane respectively,to achieve dual-band characteristic and improve theimpedance matching. The effect of standard ground-plane (SGP) of a laptop computer is incorporated in thedesign; the antenna is mounted on a SGP in order toinvestigate its performance. The antenna covers widelythe frequency bands of the WLAN 2.4 GHz (2.2–2.52 GHz)and WiMAX 3.5 GHz (3.32–4.35 GHz), and exhibits anomnidirectional radiation pattern in the H-plane and amonopole like radiation pattern in the E-plane. A goodagreement between the simulated and measured resultsindicates that the proposed dual-band antenna design issuitable for WLAN/WiMAX applications.
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    A compact ACS-fed tri-band microstrip monopole antenna for WLAN/WiMAX applications
    (Advanced Electromagnetics, 2018) Djafri, Kahina; Challal, Mouloud; Dehmas, Mokrane; Mouhouche, Faiza; Aksas, Rabia
    This paper proposes a novel small asymmetric coplanar strip (ACS) fed tri-band monopole antenna for WLAN and WiMAX applications. To tune and create multiple resonant frequencies, the exciting strip of monopole antenna is connected to two different arms which are a J-shaped directed toward the asymmetric ground plane and an open stub. The proposed monopole antenna with a total size of 14.6 x17.5 mm2 is fabricated and tested. The measured results indicate that the antenna has impedance bandwidths for 10-dB return loss reach about 500 MHz (2.01-2.52 GHz), 230 MHz (3.48-3.71 GHz) and 1.2GHz (5.59-6.72 GHz) which cover widely the 2.4/5.8 GHz WLAN bands and the 3.5GHz WiMAX band. The simulated radiation patterns of the proposed antenna at the three resonant frequencies have a dipole-like radiation pattern in both E-and H-Planes. The compact size, the simple structure and good radiation performances of the proposed antenna makes it well-suited forthe intended applications
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    Design and manufacturing of a novel compact 2.4 GHz LPF using a DGS-DMS combination and quasi octagonal resonators for radar and GPS applications
    (2019) Boutejdar, Ahmed; Challal, Mouloud; Das, Sudipta; El Hani, Soumia
    In this paper, a new compact microstrip low-pass filter (LPF) with ultra-wide stopband characteristics is presented. The combinations of DGS-DMS along with quasi octagonal resonators are employed in the design of the proposed filter to achieve compact size and ultra-wide stopband suppression level. The proposed filter has been designed, simulated, optimized and tested. The design procedure is validated using the commercial full-wave EM MoM simulator Microwave Office. Simulated as well as measured results of low-pass filter exhibit sharp roll-off (ξ) of 19 dB/GHz and creating transmission zero at around 7.8 GHz with attenuation level -54 dB. The measurement results show good agreement with the simulations. The cutoff frequency of the proposed low-pass filter is 2.4 GHz with the insertion loss less than 0.3 dB. The ultra wide stop band with over 20 dB attenuation extended from 3.42 GHz to 12 GHz. The spurious passband suppression up to six harmonics (5fc) is achieved for the proposed design. The addition of two parasitics DGS elements in the ground plane leads to suppression of the undesired harmonics and thus to improve the stopband. The size of the whole structure is less as (0.44λgx0.26λg) with λg = 68 mm. The proposed filter is useful for microwave L band, GPS system, and RADAR applications
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    Design and evaluation of an antenna applicator for a microwave colonoscopy system
    (IEEE, 2019) Guardiola, Marta; Djafri, Kahina; Challal, Mouloud; Gonzalez Ballester, Miguel A.; Fernandez-Esparrach, Gloria; Camara, Oscar; Romeu, Jordi
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    A novel dual band-notch ultrawideband monopole antenna using parasitic stubs and slot
    (wiley, 2017) Guichi, Fella; Challal, Mouloud; Denidni, T. A.
    This paper presents a novel ultra-wideband (UWB) monopole antenna with dual band-notch characteristics. The proposed antenna consists of a V-shaped patch with a stair case defect fed by a 50 X transmission line and a semicircular defected ground plane. It is designed for rejection of dual frequency bands, that is, WiMAX (3.17– 3.85 GHz) and ITU (7.9–9.1 GHz). The 2 bands are achieved by using 2 parasitic stubs that are inserted on the patch, and an inverted U-shaped slot that is etched on the transmission line, respectively. The antenna has a nearly omnidirectional radiation pattern with an acceptable gain across the operating frequency band. A good agreement between the simulated and measured results indicates that the proposed UWB antenna design with overall size of 23 3 32 mm2 is suitable for WiMAX/ITU dual band-notch applications
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    Compact UWB BPF with notch-band using SIR and DGS
    (Inderscience, 2018) Louazene, Hassiba; Challal, Mouloud; Boulakroune, M'hamed