Pour des raisons de correction et d'ajustement des resultats experimentaux nous avons procede a une verification experimentale de l'influence de plusieurs parametres sur la mesure de la diffusivite thermique par la methode flash.... more
Pour des raisons de correction et d'ajustement des resultats experimentaux nous avons procede a une verification experimentale de l'influence de plusieurs parametres sur la mesure de la diffusivite thermique par la methode flash. En effet la technique classique n'est pas efficace pour certains echantillons. Par exemple, dans le cas ou ils seraient transparents, trop poreux et/ou leur reflexivite est trop importante, nous remedions a cela en teintons les deux faces des echantillons par une peinture noire puis nous etudions les caracteristiques thermiques de celle-ci et son effet sur la mesure de la diffusivite. Dans le cas ou le temps de reponse de l'echantillon serait comparable a celui de la source, nous cherchons l'epaisseur limite de l'echantillon a partir de laquelle la mesure pourra s'effectuer.
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In this paper, a novel compact band pass filter (BPF) is proposed for global positioning system (GPS) applications. The proposed filter which is based on a microstrip resonator is mounted on a low cost RO4000 substrate with a dielectric... more
In this paper, a novel compact band pass filter (BPF) is proposed for global positioning system (GPS) applications. The proposed filter which is based on a microstrip resonator is mounted on a low cost RO4000 substrate with a dielectric constant εr=3.5, a thickness h=1.542 mm, a loss tangent tan (δ)=0.0027. It has a bandwidth from 1.55 GHz to 1.72 GHz. This filter is optimized and validated by using two electromagnetic solvers. The area occupied by this BPF is 33.6×41.24 mm2. The final circuit is a low cost BPF and can be associated with passive and active circuits due to the miniature dimensions.
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This paper presents the design of new compact antennas for ultra wide band applications. Each antenna consists of a rectangular patch fed by 50Ω microstrip transmission line and the ground element is a defected ground structure (DGS). The... more
This paper presents the design of new compact antennas for ultra wide band applications. Each antenna consists of a rectangular patch fed by 50Ω microstrip transmission line and the ground element is a defected ground structure (DGS). The aim of this study is to improve the bandwidth of these antennas by using DGS and the modification geometry of rectangular structure, which gives new compact antennas for UWB applications. The input impedance bandwidth of the antennas with S11<-10dB is more than 10GHz, from 3GHz to more than 14 GHz. The proposed antennas are investigated and optimized by using CST microwave studio, they are validated by using another electromagnetic solver Ansoft HFSS. The measured parameters present good agreement with simulation. The final antenna structures offer excellent performances for UWB system.
Research Interests: Computer Science, Physics, Wireless Communications, Electronics & Telecommunication Engineering, Microstrip Antenna, and 9 moreUltra-wideband (UWB) Communications, Microstrip, HFSS, CST Microwave Studio, Ansoft HFSS Simulator, Electrical Computer Engineering, Rectangular microstrip patch, Rectangular microstrip patch antenna (RMSA), and Ground plane
In this paper a design of a new antenna with modified ground plane is validated for multiband applications. The proposed modified ground structure is incorporated with a patch antenna to boost the performance. The antenna’s entire area is... more
In this paper a design of a new antenna with modified ground plane is validated for multiband applications. The proposed modified ground structure is incorporated with a patch antenna to boost the performance. The antenna’s entire area is 59.5x47mm2 and is printed on an FR-4 substrate and fed by a 50 Ohm microstrip line. This structure is validated in the GPS (1.56-1.58 GHz) band at 1.57 GHz, in the ISM (2.43-2.49 GHz) band at 2.45GHz and in the WiMAX (3.50-3.56 GHz) band at 3.53 GHz. These three frequency bands have good matching input impedance for, S11≤-10 dB. The antenna presents a good performance in terms of radiation pattern, and it is designed, optimized, and miniaturized by using CST-MW whose results are compared with other solvers HFSS and ADS. The results obtained by the use of the three EM solvers are in good agreement. After realization, we have tested and validated this antenna. The measurement results of the antenna present a good agreement with the numerical results.
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In this paper, we propose a novel reconfigurable patch antenna for wireless communication systems. The proposed reconfigurable antenna is based on PIN diodes associated to three U shaped resonators. The operating frequency of the proposed... more
In this paper, we propose a novel reconfigurable patch antenna for wireless communication systems. The proposed reconfigurable antenna is based on PIN diodes associated to three U shaped resonators. The operating frequency of the proposed antenna can be tuned by changing the state of the PIN diode. In this work, we modelized the PIN diode using two different methods. This circuit is mounted on an FR-4 substrate with a thickness of 1.6mm, dielectric constant of 4.4 and tangent loss of 0.025. The simulation results are performed with CST-MW studio and verified by ADS.
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In this paper a depicted survey of a Coplanar Waveguide (CPW) printed antenna achieved by using the Sierpinski Gasket as fractal geometry in the radiator which is taken as circular shape, the iterations has been performed three times in... more
In this paper a depicted survey of a Coplanar Waveguide (CPW) printed antenna achieved by using the Sierpinski Gasket as fractal geometry in the radiator which is taken as circular shape, the iterations has been performed three times in order to improve the matching of Input Impedance at 50 Ω in the Ultra-wide band (UWB), which is the frequency range 3.1-10.4 GHz released by the Federal Communications commission (FCC). The electromagnetics solvers CST of Microwave Studio have been used to design the proposed antenna by the methods of optimization included in the software tool and to compute the coefficient of reflection and the gain radiation pattern. The FR4 has been chosen as substrate to simulate the printed antenna with an overall dimension of 34 x 43 mm2.
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In this paper a novel Multi-band planar antenna structure is presented for GSM 900, DCS 1800, 3G (UMTS 2000) and 4G (LTE Advanced) applications. The antenna is optimized and simulated by using CST Microwave studio, 3-dimentional full wave... more
In this paper a novel Multi-band planar antenna structure is presented for GSM 900, DCS 1800, 3G (UMTS 2000) and 4G (LTE Advanced) applications. The antenna is optimized and simulated by using CST Microwave studio, 3-dimentional full wave electromagnetic simulation software. This antenna structure has a partial ground that was optimized into simulation. After the achievement, we have tested and validated this multi-band antenna by using R&S VNA.
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Dans cet article,nous developpons un nouveau procede de recuperation des metaux precieux contenus dans les catalyseurs de post combustion automobile usages (CPCA) ; ce procede est base sur la vaporisation reactive sous flux de gaz oxydant... more
Dans cet article,nous developpons un nouveau procede de recuperation des metaux precieux contenus dans les catalyseurs de post combustion automobile usages (CPCA) ; ce procede est base sur la vaporisation reactive sous flux de gaz oxydant chaud. Un dispositif experimental a ete concu pour effectuer cette operation. Le gaz oxydant produit par une source plasma a arc souffle, traverse le catalyseur qui est une matrice alveolaire, d'abord la matrice va se chauffer ; ce qui permettra d'arriver a une certaine temperature, ceci provoque le depart des platinoides sous forme d'oxydes gazeux. Pour optimiser les differents parametres qui regissent la vaporisation nous avons modelise les transferts de chaleur et de matiere dans la matrice alveolaire. Cette modelisation a ete faite en elaborant deux codes de calcul. Le premier concerne le transfert de chaleur et de matiere dans la veine gazeuse et a ete etablit en regime permanent, alors que le second, traitant le transfert de chale...
Research Interests: Physics and Humanities
This paper presents analysis and design of a wideband<br> Wilkinson power divider for wireless applications. The design is<br> accomplished by transforming the lengths and impedances of the<br> quarter wavelength... more
This paper presents analysis and design of a wideband<br> Wilkinson power divider for wireless applications. The design is<br> accomplished by transforming the lengths and impedances of the<br> quarter wavelength sections of the conventional Wilkinson power<br> divider into U-shaped sections. The designed power divider is<br> simulated by using ADS Agilent technologies and CST microwave<br> studio software. It is shown that the proposed power divider has<br> simple topology and good performances in terms of insertion loss,<br> port matching and isolation at all operating frequencies (1.8 GHz,<br> 2.45 GHz and 3.55 GHz).
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This paper presents a new structure of microstrip band<br> pass filter (BPF) based on coupled stepped impedance resonators.<br> Each filter consists of two coupled stepped impedance resonators<br> connected to microstrip... more
This paper presents a new structure of microstrip band<br> pass filter (BPF) based on coupled stepped impedance resonators.<br> Each filter consists of two coupled stepped impedance resonators<br> connected to microstrip feed lines. The coupled junction is utilized to<br> connect the two BPFs to the antenna. This two band pass filters are<br> designed and simulated to operate for the digital communication<br> system (DCS) and Industrial Scientific and Medical (ISM) bands at<br> 1.8 GHz and 2.45 GHz respectively. The proposed circuit presents<br> good performances with an insertion loss lower than 2.3 dB and<br> isolation between the two channels greater than 21 dB. The prototype<br> of the optimized diplexer have been investigated numerically by<br> using ADS Agilent and verified with CST microwave software.
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This work presents a new planar multiband antenna<br> based on fractal geometry. This structure is optimized and validated<br> into simulation by using CST-MW Studio. To feed this antenna we<br> have used a CPW line... more
This work presents a new planar multiband antenna<br> based on fractal geometry. This structure is optimized and validated<br> into simulation by using CST-MW Studio. To feed this antenna we<br> have used a CPW line which makes it easy to be incorporated with<br> integrated circuits. The simulation results presents a good matching<br> input impedance and radiation pattern in the GSM band at 900 MHz<br> and ISM band at 2.4 GHz. The final structure is a dual band fractal<br> antenna with 70 x 70 mm² as a total area by using an FR4 substrate.
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This paper presents a new design of a fractal multiband antenna structure fed by coplanar waveguide (CPW) transmission line. The proposed antenna is optimized by using CST-MW studio. The final validated circuit is designed to operate in... more
This paper presents a new design of a fractal multiband antenna structure fed by coplanar waveguide (CPW) transmission line. The proposed antenna is optimized by using CST-MW studio. The final validated circuit is designed to operate in the Global Positioning System (GPS 1.57), Worldwide Interoperability for Microwave Access (WiMAX 2.5 – 2.69 / 3.30 – 3.80), and Advanced System of forth generation mobile communication (IMT 3.40 – 4.20 GHZ). Manifestly, it has been found that the radiation patterns of the presented antenna are still similarly to the bidirectional radiation pattern. The properties of the antennas, for instance, return losses and radiation patterns are validated into simulation by using two electromagnetic simulators HFSS and CST-MW Studio.
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In this work, a novel compact microstrip low-pass filter is designed based on square split ring resonator. The SRR is used to reduce the size of the filter and to improve the good electrical performances. The dumbbell-shaped defected... more
In this work, a novel compact microstrip low-pass filter is designed based on square split ring resonator. The SRR is used to reduce the size of the filter and to improve the good electrical performances. The dumbbell-shaped defected ground structure is introduced into the ground plane in order to achieve a desired cutoff frequency of 1.2 GHz with a ripple level less than 0.2 dB in the pass-band and an attenuation better than 20 dB in the rejected band. The proposed filter is designed on an FR-4 substrate having a thickness of 1.6mm, a dielectric constant of 4.4 and loss tangent of 0.025. The whole area of the proposed circuit is 24×26mm2. The computed results obtained by CST microwave and Ansoft HFSS are in good agreement. The size of LPF is miniaturized by 60% compared to the conventional filter.
Research Interests: Engineering and IEEE
The concept of Defected Ground Structures (DGS) has been developed to improve the characteristics of many microwave devices. For this purpose the DGS is also used in the microstrip antenna for some advantages such as antenna size... more
The concept of Defected Ground Structures (DGS) has been developed to improve the characteristics of many microwave devices. For this purpose the DGS is also used in the microstrip antenna for some advantages such as antenna size reduction, mutual coupling reduction in antenna arrays etc… In this paper the defected ground structure (DGS) has been employed to miniaturize a microstrip patch antenna and to shift the resonance frequency from an initial value of 10 GHz to a final value at 3.5 GHz, without any change in the dimensions of the original microstrip patch antenna. This antenna is designed on a FR-4 substrate with dielectric constant 4.4 and thickness 1.6 mm and its size is 27 × 30 mm2. The antenna is designed, optimized, and miniaturized by using CST MW.
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In this paper, a novel design of metamaterial passive tag antenna for radio frequency identification operating in the UHF band is proposed. The design of the proposed tag antenna included a meandering technique to match the antenna with... more
In this paper, a novel design of metamaterial passive tag antenna for radio frequency identification operating in the UHF band is proposed. The design of the proposed tag antenna included a meandering technique to match the antenna with the tag chip and a complementary split ring resonator to reduce the antenna size. An advanced Photopaper substrate having a permittivity of 3.3, loss tangent of 0.04 and thickness of 0.25mm is used to design this tag antenna. The dimensions of the proposed tag antenna are optimized by using ADS. The total size of this circuit is 84.6 × 28mm2. The performance of the proposed tag antenna is evaluated and analyzed based on gain, return loss, matching input impedance and read range. The simulated reflection coefficient is about −35dB at 915MHz, the impedance bandwidth is about 32.8MHz, gain is 1.8dB, and the read range is about 6.2 m.
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In this paper, a new reconfigurable planar antenna structure operating for wireless applications is presented. The multiband antenna is based on varactor diodes in order to achieve the tuning of the frequency bands. This circuit is... more
In this paper, a new reconfigurable planar antenna structure operating for wireless applications is presented. The multiband antenna is based on varactor diodes in order to achieve the tuning of the frequency bands. This circuit is mounted on an FR-4 substrate with a thickness of 1.58 mm, dielectric constant of 4.4, tangent loss of 0.025 and fed by a microstrip line. The antenna is optimized and simulated by using CST-MW studio. This antenna has an area of 40x40 mm2.
Research Interests: Materials Science and Acm
A 45 degree differential microstrip phase shifter operating in the frequency band ranging from 1.4 GHz to 2.7 GHz is presented in this paper. It is designed by adopting the model of double parallel Schiffman phase shifter and simulated on... more
A 45 degree differential microstrip phase shifter operating in the frequency band ranging from 1.4 GHz to 2.7 GHz is presented in this paper. It is designed by adopting the model of double parallel Schiffman phase shifter and simulated on an FR4 substrate by using two electromagnetic simulation software, ADS from Agilent technologies and CST Microwave Studio. The proposed phase shift circuit offers good results in terms of return loss, insertion loss and phase shift. Good agreement between simulated results using ADS and CST Microwave Studio is obtained.
Research Interests: Engineering and IEEE
A microstrip patch antenna using modified shape defect as defected ground structure (DGS) is presented in this paper. The proposed DGS is integrated in the ground plane of the patch antenna for shifted the resonance frequency from 5.8 GHz... more
A microstrip patch antenna using modified shape defect as defected ground structure (DGS) is presented in this paper. The proposed DGS is integrated in the ground plane of the patch antenna for shifted the resonance frequency from 5.8 GHz to 2.45 GHz, with better performance miniaturization up to 82%. The antenna is mounted on an FR-4 substrate with a height of 1.6mm and relative permittivity of 4.4 and its size is 34 X 34 mm2. The antenna is designed, optimized, and miniaturized by using CST MW. The antenna is designed to operate in the ISM 'Industrial and Scientific Medical' band at 2.45 GHz.
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This paper presents a new design of a multiband planar inverted-F antenna for GPS/Bluetooth/WIFI applications. The proposed antenna is mounted on an FR4 substrate and having the whole volume of 100x50x1.6mm3. The technique used to obtain... more
This paper presents a new design of a multiband planar inverted-F antenna for GPS/Bluetooth/WIFI applications. The proposed antenna is mounted on an FR4 substrate and having the whole volume of 100x50x1.6mm3. The technique used to obtain a multiband behavior is the same technique of PIFA structure with introducing slots that are cut in the antenna radiation patch, which permits to obtain three operating frequency bands. The proposed antenna can cover the operating frequencies of GPS (1.561.74GHz), Bluetooth/WIFI (2.4.2.5GHz), bands. The characteristics of the proposed antenna are validated by using the electromagnetic solver CST Microwave Studio.
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This paper presents a new design of negative resistance oscillator with low phase noise by using microwave microstrip technology. This microstrip oscillator is designed at 2.4 GHz frequency for applications in mobile communication,... more
This paper presents a new design of negative resistance oscillator with low phase noise by using microwave microstrip technology. This microstrip oscillator is designed at 2.4 GHz frequency for applications in mobile communication, wireless network, wireless fidelity, and Bluetooth. The final circuit is designed by using microstrip distributed resonator. The distributed resonator can be modeled by using the parallel RLC at the resonant frequency. The high Q factor of the resonator provides high carrier output power and low phase noise. The output power is obtained around 7.902dBm at 2.4 GHz with 2V DC supply and 12 mA current consumption. In this proposed oscillator, each step has been analyzed by using Advanced Design System ADS and following a theoretical study which permits to optimize the different performances of the whole circuit.
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This paper presents a study of a new fractal antenna mounted on FR4 substrate with overall dimensions of 34×43mm2. The radiator geometry shape is achieved by using the concatenation between circular and rectangular shapes with four... more
This paper presents a study of a new fractal antenna mounted on FR4 substrate with overall dimensions of 34×43mm2. The radiator geometry shape is achieved by using the concatenation between circular and rectangular shapes with four iterations juxtaposed. Two slots have been inserted in the ground planes which improve the matching of input impedance in the frequency range 2.79 - 11 GHz with a VSWR less than 2 and a bandwidth of 119%. This antenna will operate in Ultra Wideband (UWB) frequency band `3.1-10.6 GHz' which is the commercial frequency band provided by Federal Communications Commission (FCC). The Coplanar Waveguide (CPW) line used to feed the designed antenna which can make it easy for integration with microwave integrated circuit. The design and validation into simulation of the fractal antenna has been performed by using the electromagnetic software CST-Microwave Studio.
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This paper presents a new structure of microstrip diplexer based on triangular loop resonators. The diplexer is composed of two bands pass filters for the WiMAX applications at 3.2 GHz (IEEE 802.16 WiMAX at 3.17 GHz to 4.2 GHz bands) and... more
This paper presents a new structure of microstrip diplexer based on triangular loop resonators. The diplexer is composed of two bands pass filters for the WiMAX applications at 3.2 GHz (IEEE 802.16 WiMAX at 3.17 GHz to 4.2 GHz bands) and the WLAN applications at 2.4 GHz (IEEE 802.11 WLAN at 2.4 GHZ to 2.5 GHz). Two triangular resonators connected with a transmission line are used to form each filter with a matching network used to connect the two BPFs with the antenna. The diplexer has less than 2 dB insertion loss and more than 23 dB of isolation. This prototype diplexer is designed for a multiband system operating in the 2.4/3.2GHz respectively. The simulation results are investigated by using ADS from Agilent Technologies.
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This paper presents a novel fractal antenna structure<br> proposed for UWB (Ultra – Wideband) applications. The frequency<br> band 3.1-10.6GHz released by FCC (Federal Communication<br> Commission) as the commercial... more
This paper presents a novel fractal antenna structure<br> proposed for UWB (Ultra – Wideband) applications. The frequency<br> band 3.1-10.6GHz released by FCC (Federal Communication<br> Commission) as the commercial operation of UWB has been chosen<br> as frequency range for this antenna based on coplanar waveguide<br> (CPW) feed and circular shapes fulfilled according to fractal<br> geometry. The proposed antenna is validated and designed by using<br> an FR4 substrate with overall area of 34x43 mm2. The simulated<br> results performed by CST-Microwave Studio and compared by ADS<br> (Advanced Design System) show good matching input impedance<br> with return loss less than -10dB between 2.9 GHz and 11 GHz.
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In this work, we present the design and analysis of compact coplanar waveguide-fed ultra wideband rectangular antennas. These proposed antennas exhibit very wide operating bandwidth (return loss ≤ -10dB) which covers 3.2-15 GHz range,... more
In this work, we present the design and analysis of compact coplanar waveguide-fed ultra wideband rectangular antennas. These proposed antennas exhibit very wide operating bandwidth (return loss ≤ -10dB) which covers 3.2-15 GHz range, which means a relative bandwidth of 126% covering FCC defined UWB band with stable omnidirectional radiation patterns and important gain. The parameters of antennas have been investigated and optimized by using two electromagnetic solvers. A good agreement has been obtained between simulation and measurement results. These antennas are useful for UWB indoor applications, handheld and wireless communication requiring low profile antennas. The antennas achieved are low cost and easy to fabricate and integrate with RF circuit. The simulated and the experimental results are described and discussed.