Browsing by Author "Azrar, A."

Filter results by typing the first few letters
Now showing 1 - 19 of 19
  • No Thumbnail Available
    Item
    Analysis of a printed X-Shaped monopole antenna
    (IEEE, 2017) Dehmas, Mokrane; Hamza, A. A.; Challal, Mouloud; Benmahdjoub, I.; Azrar, A.; Djafri, K.; Mouhouche, Faiza
    This paper presents a study of a printed X-shaped monopole antenna. The analysis has started from considering a strip fed conventional single band Rectangular Microstrip Antenna (RMSA) resonating at 2.45 GHz commonly used in WLAN applications. The antenna has been transformed to a monopole structure that has yielded a larger bandwidth. In the second part, triangular slots were introduced to the RMSA to obtain an X-shaped antenna and their effects were investigated. An X-shaped monopole structure presenting a bandwidth of 3.39 GHz (1.96-5.35 GHz) has been obtained. The analysis suggested a possibility of performing size reduction. This part resulted in a final X-shaped monopole printed structure with an enhanced bandwidth of 6.2 GHz (1.8-8.0 GHz) and a significant external size reduction of 55.48 %. The final antenna which can be used in various applications (WLAN, Wi-Fi, Wi-Max, LTE 4G, surveillance systems, medical imaging, etc.) has been fabricated and its reflection coefficient measured. Good agreement was noticed between the simulated and measured results.
  • No Thumbnail Available
    Item
    Compact dual band slotted triangular monopole antenna for RFID applications
    (Wiley, 2017) Dehmas, Mokrane; Azrar, A.; Mouhouche, Faiza; Djafri, K.; Challal, Mouloud
  • No Thumbnail Available
    Item
    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.
  • No Thumbnail Available
    Item
    Compact dual-band reject UWB monopole antenna using EBG structures
    (IEEE, 2017) Mouhouche, Faiza; Azrar, A.; Dehmas, Mokrane; Djafri, K.
    In this paper, a compact dual band notched UWB monopole antenna is presented for WiMAX and X-band satellite applications. Dual band rejection characteristics are achieved by engraving the complementary hexagonal spit ring metamaterial on the radiating element and two modified mushrooms-like EBG structure above the ground plane on the vicinity of feed line. The antenna prototype is fabricated and tested. A good agreement between the simulated and measured results. The radiation pattern and time domain of the proposed design are relatively stable
  • No Thumbnail Available
    Item
    A compact superformula based ultra-wideband antenna shape with two notched bands
    (wiley, 2018) Mouhouche, Faiza; Azrar, A.; Dehmas, Mokrane; Djafri, Kahina
    In this paper, a compact superformula ultra‐wideband (UWB) monopole antenna with dual band notches is proposed. The developed structure achieves UWB performance as well as a compact size of 20 × 26 × 1.62 mm3. Furthermore, to avoid interferences with WiMAX and satellite communication systems, dual notched band is obtained by engraving two co‐directional triangular split ring defects on the radiating element. The simulated and measured results show that the proposed antenna has an impedance bandwidth extending from 3.05 to 20 GHz with dual notched bands at [5.15‐5.68 GHz], and [7.15‐7.65 GHz] used in WiMAX and satellite communication, respectively. The proposed design realizes omnidirectional radiation pattern in H‐plane, and a dipole‐like pattern in E‐plane. The antenna exhibits an acceptable gain in the whole UWB range except at notched bands.
  • No Thumbnail Available
    Item
    Design a Compact UWB Monopole Antenna with Triple Band-Notched Characteristics Using EBG Structures
    (2018) Mouhouche, Faiza; Azrar, A.; Dehmas, Mokrane; Djafri, K.
    in this paper, a compact ultra-wideband (UWB)monopole antenna with triple band-notched characteris-tics is presented. These triple band rejections are pro-duced by inserting the Complementary Co-directionalSplit-Ring Resonator (CC.SRR) on the radiating elementfor WiMAX/WLAN (3.4–3.95 GHz/5.35–5.9 GHz) andElectromagnetic Band Gap (EBG) structure in the vicinityof transmission line for X-band satellite communications(6.7–7.7 GHz). The proposed antenna with a total size of18 × 20.9 × 1.63 mm3has been constructed and tested. Anequivalent RLC circuit model is proposed and investi-gated. The simulated and measured results show thatthe proposed antenna has an impedance bandwidth(VSWR < 2) extanding from 3.05 GHz to 14 GHz with triplenotched bands of [3.3–3.9 GHz], [5.25–5.86 GHz] and [6.7–7.7 GHz]. The triple band notched characteristics and thegood radiation patterns make the proposed antenna agood candidate for the UWB applications
  • No Thumbnail Available
    Item
    Design of compact low pass filter with large reject band using open circuit stubs and two cascaded DGS-Quasi-triangular resonators
    (2013) Challal, Mouloud; Boutejdar, A.; Azrar, A.; Vanhoenacker-Janvie, D.
    This article investigates a quasitriangular of defected ground structure (DGS) for low-pass filters (LPFs) application. An equivalent RLC circuit model is presented and its corresponding designed and fabricated. The proposed LPF presents the advantages of small size, low insertion loss and ultrawide stopband with 20 dB attenuation from 4 GHz to > 20 GHz. The simulated results obtained by equivalent circuit model and full-wave electromagnet show good agreement with the measured ones. V C 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:122–127, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27260 parameters are as well extracted using the parametric relationships. The LPFs using the proposed DGS pattern combined with open stubs are
  • No Thumbnail Available
    Item
    Dual band monopole antenna using metamaterials
    (IEEE, 2017) Mouhouche, Faiza; Azrar, A.; Djafri, K.
  • No Thumbnail Available
    Item
    Effect of eyes and eyebrows on face recognition system performance
    (IEEE, 2014) Radji, N.; Cherifi, Dalila; Azrar, A.
  • No Thumbnail Available
    Item
    Gain improvement of CPW-Fed monopole antenna over dual-band AMC structure
    (IEEE, 2017) Mouhouche, Faiza; Azrar, A.; Dehmas, M.; Djafri, K.
    A CPW rectangular-ring antenna over an Artificial Magnetic Conductor (AMC) is presented in this work. The AMC is designed as a dual-band structure having an array of unit cells and operates at 2.45GHz and 5.20 GHz. A CPW antenna uses this dual-band AMC structures as a back-plane. Performance comparison is carried out with and without the incorporation of AMC. The simulated and measured results show that the combination of the AMC reflector and the antenna provide directional properties at both frequency bands. It has been found that the antenna gain increases by about 5 dB
  • No Thumbnail Available
    Item
    Microstrip design of low noise amplifier for application in narrowband and wideband
    (IEEE, 2008) Challal, Mouloud; Azrar, A.; Bentarzi, Hamid; Janvier, D.V
    A low-noise amplifier (LNA) is presented in this paper. The LNA is designed and optimized for narrowband and wideband operations along with minimum noise figure around 24 GHz (K-Band). The designed LNA employs microstrip input and output matching networks; it achieves a noise figure of 3.85 dB and 10.55 dB of gain along with 10.27 dB and 17.83 dB of input and output return losses, respectively for its narrow band. Where as for its wideband it accomplishes a gain of 6.5 dB with ±0.3 dB flatness from 24 to 25.25 GHz wideband frequency range, the noise figure obtained for the presented LNA is in close proximity to the minimum noise figure over 23 - 24.5 GHz frequency range
  • No Thumbnail Available
    Item
    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
  • No Thumbnail Available
    Item
    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.
  • No Thumbnail Available
    Item
  • No Thumbnail Available
    Item
    A semi numerical approach for semiconductor devices physical modeling
    (IEEE, 2009) Dehmas, Mokrane; Azrar, A.; Recioui, Abdelmadjid; Challal, Mouloud
    In this work, the developed mathematical extension of the semi analytical Method of Lines (MoL) for the solution of Poisson's equation which governs the voltage distribution within semiconductor devices is adapted to fit realistic considerations related to the geometry and the electrodes configuration of such structures. The obtained tool is then applied to find the potential profile within a MOS capacitor in deep depletion mode
  • No Thumbnail Available
    Item
    Subband selection in wavelet packet decomposition for face recognition
    (IEEE, 2013) Radji, N.; Cherifi, Dalila; Azrar, A.
  • No Thumbnail Available
    Item
    Two-stage 24 GHz low noise amplifier for front-end receiver system
    (IEEE, 2012) Challal, Mouloud; Vanhoenacker Janvier, D.; Azrar, A.
  • No Thumbnail Available
    Item
    Use of genetic algorithms in linear and planar antenna array synthesis based on Schelkunoff method
    (2007) Recioui, Abdelmadjid; Azrar, A.
    Genetic algorithms coupled with the Schelkunoff synthesis method are used to synthesize equispaced linear and planar arrays. The purpose is to find the different excitation amplitudes and phases to achieve good matching between the desired and calculated radiation patterns. Examples which demonstrate the versatility of the approach presented in this article are considered for various patterns including the steered pattern case. The planar array is treated as a set of two separate linear arrays upon which Schelkunoff method is applied separately
  • No Thumbnail Available
    Item
    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