Electronique

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A 2 GHz low power, highly tunable and low phase noise monolithic LC VCO in 0.35 μm CMOS technology

L. Bouzerara, M.T. Belaroussi, Aicha ZIOUCHE  (2004)
Publication

In this paper, a fully integrated 2 GHz low phase noise LC-tank VCO, designed in 0.35 μm CMOS technology is presented and analyzed. The phase noise of the VCO has been greatly reduced by means of integrated source degeneration inductors. The phase noise achieved is -108, -125 dBc/Hz and -139 dBc/Hz at 100 kHz, 600 kHz and 3 MHz offsets respectively from the carrier frequency of 2 GHz, with 2.5 V power supply voltage and giving a power consumption of 10.35 mW. A 20.3% wide tuning range is achieved by means of PMOS varactors and a degeneration resistor. The tunability of the designed oscillator covers 380 MHz, from 1.68 GHz up to 2.06 GHz with a VCO gain of 280 MHz/V. The proposed VCO is fully operational under variable conditions including temperature and supply voltage variations from -40°C to 85°C and 2.5 V ±10%, respectively. Voir les détails

Mots clés : inductors, low phase noise, 0.35 μm CMOS technology

Characteristics of a high Tc superconducting rectangular microstrip patch on uniaxially anisotropic substrate

Siham BENKOUDA, Abderraouf MESSAI, Mounir AMIR, Sami BEDRA, Tarek FORTAKI  (2014)
Publication

Resonant characteristics of a high Tc superconducting rectangular microstrip patch printed on uniaxially anisotropic substrate are investigated using a full-wave spectral analysis in conjunction with the complex resistive boundary condition. The uniaxial medium shows anisotropy of an electric type as well as anisotropy of a magnetic type. Both permittivity and permeability tensors of the substrate are included in the formulation of the dyadic Green’s function of the problem. The accuracy of the analysis is tested by comparing the computed results with previously published data for several anisotropic substrate materials. Numerical data of the resonant frequency and bandwidth as a function of electric anisotropy ratio are presented. Variations of the resonant frequency and bandwidth with the magnetic anisotropy ratio are also given. Finally, results showing the influence of the temperature on the resonant frequency and quality factor of the high Tc superconducting rectangular microstrip patch on a uniaxial substrate are also given. Voir les détails

Mots clés : superconducting microstrip patch, Anisotropic substrate, Permittivity and permeability tensors

Bacterial foraging optimisation and method of moments for modelling and optimisation of microstrip antennas

Mounir AMIR, Sami BEDRA, Siham BENKOUDA, Tarek FORTAKI  (2014)
Publication

A novel technique applying bacterial foraging optimisation (BFO) in conjunction with the method of moments (MOM) is developed to calculate accurately the resonant frequency and bandwidth of rectangular microstrip antenna of any dimension and of any substrate thickness. The resonant frequency results obtained by using (BFO/MOM) algorithm are in very good agreement with the experimental results available in the literature. The computation time is greatly reduced as compared with the classical MOM. Furthermore, the idea of this paper can be used for calculating the various parameters of microstrip antennas of different structures and geometries. Voir les détails

Mots clés : method of moments, microstrip antennas, natural frequencies, bacterial foraging, Computation time, Different structure, Method of moments (MOM), Modelling and optimisation, Novel techniques, Rectangular-microstrip antennas, Substrate thickness

Analysis of High TSuperconducting Rectangular Microstrip Patches over Ground Planes with Rectangular Apertures in Substrates Containing Anisotropic Materials

Abderraouf MESSAI, Siham BENKOUDA, Mounir AMIR, Sami BEDRA, Tarek FORTAKI  (2013)
Publication

A rigorous full-wave analysis of high superconducting rectangular microstrip patch over ground plane with rectangular aperture in the case where the patch is printed on a uniaxially anisotropic substrate material is presented. The dyadic Green’s functions of the considered structure are efficiently determined in the vector Fourier transform domain. The effect of the superconductivity of the patch is taken into account using the concept of the complex resistive boundary condition. The accuracy of the analysis is tested by comparing the computed results with measurements and previously published data for several anisotropic substrate materials. Numerical results showing variation of the resonant frequency and the quality factor of the superconducting antenna with regard to operating temperature are given. Finally, the effects of uniaxial anisotropy in the substrate on the resonant frequencies of different TM modes of the superconducting microstrip antenna with rectangular aperture in the ground plane are presented. Voir les détails

Mots clés : Anisotropic material, Anisotropic substrates, Dyadic green's functions, Operating temperature, Rectangular aperture, Rectangular microstrip patch, Superconducting microstrip antennas, Uniaxially anisotropic substrate

Resonant Frequency of Tunable Microstrip Ring Antenna Printed on Isotropic or Uniaxially Anisotropic Substrate

Sami BEDRA, Siham BENKOUDA, Mounir AMIR, Tarek FORTAKI  (2013)
Publication

In this study, the resonant frequency of annular ring microstrip resonator with uniaxial anisotropic substrate and air gap layer is analyzed. The cavity model for simple ring microstrip antenna is extended with some modifications for the tunable geometry taking into account the anisotropy inthe layer. The theoretical resonant frequency results are in very good agreement with the experimental results reported elsewhere. The air gap tuning effect on the resonant characteristics is also investigated for fundamental and higher order modes. Voir les détails

Mots clés : Microstrip, Ring Antenna

Resonance of High Tc Superconducting Microstrip Patch in a Substrate-Superstrate Configuration

Siham BENKOUDA, Tarek FORTAKI, Mounir AMIR, Abdelmadjid BENGHALIA  (2013)
Publication

The effect of a protecting dielectric superstrate on the resonance of a high Tc superconducting microstrip patch is investigated. The analysis approach is based on the spectral-domain method of moments in conjunction with the complex resistive boundary condition. The complex surface impedance of the superconducting thin film is determined using London’s equation and the two-fluid model of Gorter and Casimir. Numerical results show that the resonant frequency of the high Tc superconducting rectangular patch decreases monotonically with increasing superstrate thickness, the decrease being greater for high permittivity loading. Voir les détails

Mots clés : Resonance, Microstrip antenna, Superstrate

Dual-Frequency Behavior of Stacked High Tc Superconducting Microstrip Patches

Siham BENKOUDA, Mounir AMIR, Tarek FORTAKI, Abdelmadjid BENGHALIA  (2011)
Publication

The dual-frequency behavior of stacked high Tc superconducting rectangular microstrip patches fabricated on a two-layered substrate is investigated using a full-wave spectral analysis in conjunction with the complex resistive boundary condition. Using a matrix representation of each layer, the dyadic Green's functions of the problem are efficiently determined in the vector Fourier transform domain. The stationary phase method is used for computing the radiation electric field of the antenna. The proposed approach is validated by comparison of the computed results with previously published data. Variations of the lower and upper resonant frequencies, bandwidth and quality factor with the operating temperature are given. Results showing the effects of the bottom patch thickness as well as the top patch thickness on the dual-frequency behavior of the stacked configuration are also presented and discussed. Finally, for a better comprehension of the dual-frequency operation, a comparison between the characteristics of the lower and upper resonances is given Voir les détails

Mots clés : Dual-frequency operation, Stacked patches, Superconducting microstrip patches

The effect of a high temperature superconducting patch on a rectangular microstrip antenna

Fouad CHEBBARA, Mounir AMIR, Tarek FORTAKI  (2009)
Publication

The complex resonant frequency problem of a superconductor patch is formulated in terms of an integral equation which is the kernel of a dyadic Green's function. To include the effect of the superconductivity of the microstrip patch, the surface complex impedance of the superconductor film is introduced using the two fluids model of Gorter and Casimir. The Galerkin procedure is used in the resolution of the electric field integral equation. Numerical results concerning the effect of the operating temperature of a superconductor patch on the characteristics of the antenna are presented. Voir les détails

Mots clés : Dyadic Green's function, Galerkin procedure, HTS microstrip patch, Microstrip antenna, Superconducting patch

Air gap tuning effect on the resonant frequency and half-power bandwidth of superconducting microstrip patch

Tarek FORTAKI, Siham BENKOUDA, Mounir AMIR, Abdelmadjid BENGHALIA  (2009)
Publication

An accurate analysis of an air gap tuned high Tc superconducting microstrip antenna is presented. To include the effect of the superconductivity of the microstrip patch in the Full wave analysis of the tunable rectangular microstrip patch, a surface complex impedance is considered. This impedance is determined by using London's equation and the model of Gorter and Casimir. Numerical results obtained are found to be in excellent agreement with the theoretical and experimental data available in the literature. Finally, numerical results for the air gap tuning effect on the operating frequency and bandwidth of the high Tc superconducting microstrip antenna are also presented. Voir les détails

Mots clés : Bandwidth, natural frequencies, Accurate analysis, Air gap tuning effect, Full wave analysis, Numerical results, Operating frequency, Rectangular microstrip patch, Superconducting microstrip antennas, Superconducting microstrips

Study of High Tc Superconducting Microstrip Antenna

Tarek FORTAKI, Mounir AMIR, Siham BENKOUDA, Abdelmadjid BENGHALIA  (2009)
Publication

Resonant characteristics of microstrip antennas with superconducting films is presented. The analysis is based on a full electromagnetic wave model with London's equations and the two-fluid model. It is shown that the full-wave analysis presented here gives numerical results which are in excellent agreement with the measured data available in the literature. Re- sults showing the effect of the temperature on the resonant frequency and half-power bandwidth of superconducting microstrip antenna are given. Variations of the resonant frequency with the high Tc superconducting film thickness are also presented. Voir les détails

Mots clés : Electromagnetic waves, microstrip antennas, Superconducting films, Full wave analysis, High-T, Numerical results, Resonant characteristics, Superconducting microstrip antennas, Two fluid model