Publications Internationales

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

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Author: search.filters.author.Challal, Mouloud

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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 Novel Design of a Microstrip Antenna Array for Wireless Power Transfer Applications
    (Springer, 2024) Dehmas, Mokrane; Challal, Mouloud; Arous, Abdelali; Haif, Hamza
    In this article, a new 1 × 4 microstrip antenna array operating at 2.45 GHz for wireless power transfer (WPT) applications is proposed. Besides the array configuration, and for maximum power transfer to the load, the performed design puts into contribution three other design techniques which are: defected ground structure, electromagnetic band gap and multilayer topology. The suggested antenna, printed on an FR-4 dielectric substrate, achieves significantly improved directivity and gain of 13.30 dBi and 10.90 dBi, respectively. Furthermore, an input reflection coefficient around − 38 dB, a frequency bandwidth of about 180 MHz and a side lobe level (SLL) below − 20 dB are obtained. It is also observed that the antenna gain is close to its maximum performance across the entire operating frequency band (2.36–2.54 GHz). A prototype of the performed design is fabricated and tested. Experimental results show a good agreement between simulated and measured input reflection coefficients. The achieved performances make the developed structure highly suitable for WPT systems.
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    A novel miniaturized V-shaped monopole antenna for GSM/WiMAX/WLAN applications
    (De Gruyter, 2023) Fertas, Khelil; Fertas, Fouad; Challal, Mouloud; Denidni, Tayeb A.
    This paper presents a novel miniaturized triple band V-shaped antenna (VSA). The miniaturization and the triple-band operation are obtained by performing two V-shaped turns on the metallic strip. The proposed antenna is printed on a single FR4 substrate and fed using the coplanar waveguide (CPW) technique. It operates in three frequency bands, [1.6–1.95 GHz], [2.8–4.4 GHz] and [5.4–5.8 GHz], with stable bidirectional radiation patterns in both E- and H-planes. A prototype of the designed antenna is fabricated and tested where the observed good agreement between simulated and experimental results indicates that the proposed structure, having a reasonably compact size of 0 . 0166 λ 2 0 , is suitable for GSM [1800 MHz], WiMAX [3.4–3.77 GHz] and WLAN [5.725–5.825 GHz] applications
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    Design of miniaturized tri-band antenna based on differential evolution algorithm
    (John Wiley and Sons Inc, 2023) Fertas, Fouad; Fertas, Khelil; Denidni, Tayeb A.; Challal, Mouloud
    A novel highly miniaturized triple band structure based on Z-slots-shaped antenna is presented in this letter, with only 0.0015 (Formula presented.) footprint, where (Formula presented.) is the free space wavelength at 1.3 GHz. The proposed design can generates three resonant frequency bands (1.3–1.62 GHz), (2.22–2.59 GHz), and (3.24–3.65 GHz) with −10 dB reflection coefficient, a triple band function is achieved by etching tow connected Z-shaped-slots in the radiating element and the differential evolution algorithm is then used to control the currents path, the prototype of the proposed antenna is printed on a single substrate layer and fed via coplanar waveguide CPW technology. The measured and simulated results are in good agreement, and validate the design principle, the results show that the antenna has a compact size (19.5 × 17.6 mm2), aside from its planar design, simple manufacturing, and low cost to fabricate, this antenna exhibits stable omnidirectional radiation patterns in E plane as well as bidirectional radiation patterns in H plane, making it an ideal device for multiband applications
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    A compact double-inverted Ω-shaped dual-band patch antenna for WLAN/WiMAX applications
    (Frequenz : journal of RF-engineering and telecommunications, 2022) Djafri, Kahina; Mouhouche, Faiza; Dehmas, Mokrane; Challal, Mouloud
    In this study, a new compact dual-band antenna with overall size of 11 × 14.46 × 1.6 mm3 has been designed, fabricated and tested. The proposed antenna consists of two inverted Ω-shaped strips loaded with two different comb structures. The fist comb of six elements connected to the first Ω-shaped radiating branch is used to decrease the second band lower cut-off frequency and cover the intended WLAN and WiMAX applications. In order to cover the 2.45 GHz WLAN band and further reduce the antenna dimensions, a second comb structure of 14 elements is attached to the upper radiating branch. The fabricated antenna covers the frequency bands from 2.42 to 2.6 GHz and from 4.25 to 6.77 GHz with a reflection coefficient of |S 11| ≤ −10 dB. The antenna shows an omnidirectional radiation pattern in the H-plane and a monopole-like radiation pattern in the E-plane. The measured results agree well with the simulated ones which indicate that the proposed antenna is suitable to be used in the WLAN/WiMAX applications
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    Compact dual-band fractal hexagonal ring monopole antenna for RFID and GSM applications
    (wiley, 2018) Djafri, Kahina; Challal, Mouloud; Azrar, A.; Dehmas, Mokrane
    A novel compact dual‐band fractal antenna suitable for radio frequency identification (RFID) and GSM 1800 applications is developed and presented in this paper. This is achieved by adequate combination of three slotted hexagonal fractal rings which resulted in a significantly reduced size structure that can operate in the frequency ranges [0.895‐0.962 GHz] and [1.706‐1.856 GHz] that cover the frequency bands allocated to the intended applications. The proposed antenna has been fabricated and its reflection coefficient measured where a good agreement is observed with the simulated results.
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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