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Compared with measurement and the finite different method, the present technique is found to be efficient with 2D analysis and a required low memory. This article presents a new hybrid technique which combines two different numerical methods in the frequency domain, namely the Frequency Domain Transmission Line Matrix fdtLM and the Wave Concept Iterative Process, to analyse three-dimensional 3D microwave structures.

As a result, a considerable reduction of the computation time and required computer memory is achieved compared with the classic fdtLM. The good agreement between simulation results and experimental published data validates the present analysis approach. This paper covers the design of electrical model of Sierpenski fractal antenna.

The proposed model is based on the electrical model of triangular patch. Each elementary triangle of Sierpenski patch is replaced by its model and then the whole model is built. The return loss of the model is compared to both a physical patch and another electrical model. The proposed model has the same resonant frequency with the antenna and a few differences in band width and itpsilas very useful for parametric analysis of the Sierpenski gasket antenna.

This work can open other opportunities in the electrical modeling of fractal antennas. Phase-only adaptive nulling with neural networks for antenna array synthesis. A new approach to adaptive phase-only nulling with phased arrays is described. An efficient method is presented to synthesise directive beam and multi-beam patterns and create adaptive nulls in interference direction. The proposed method is based on iterative minimisation of a function that incorporates constraints imposed in each direction with respect to excitation phases and neural network technique. Various results are presented to show the advantages and limitations of this approach.

The back-propagation algorithm proves to be better than previous phase-only adaptive algorithms. To verify the performances of the proposed technique, an eight-element array has been realised and tested for various types of beam configurations. A joint space-time estimation algorithm for wideband signals with high resolution capabilities. The measurement of the directions of arrival using an antennas array is limited by the number of detected sources. Thus, the number of antennas must be higher than the number of signals.

To overcome this difficulty, we present in this paper, a joint estimation angle-delay method based on the MUSIC algorithm in wideband conditions. The phase difference between the signals collected by the antennas makes it possible to calculate the DOA's, and the phase difference between the consecutive frequencies of the complex envelope in each antenna allows estimating the delays. The simulation results show the effectiveness of the method and that we can estimate a number of sources higher than the number of elements in the array.

Unlike several estimation methods which require full knowledge of MIMO propagation channel, others which require that the number of antenna in the mobile terminal be higher than the number of sources to estimate or other requiring high computational complexity, our estimation approach was proposed to solve a great number of multipaths associated with several users in unknown rich scattering multiuser environment adopting smaller mobile terminals with low number of antenna elements.

A novel wideband butler matrix using multi-layer technology. A four-antenna array was connected to the matrix to build a beam-forming system for beam steering. This matrix is suitable for wideband communication systems. New tunable coplanar microwave phase shifter with nematic crystal liquid. Jan Design and Test Workshop, The liquid crystals known for their applications as viewers have interesting features for a microwave circuit design's so-called "agile frequency". These circuits offer the advantage to change their frequency response according to an external command.

Here we present a new phase shifter agile frequency liquid crystal substrate. Indeed the nature of viscous liquid crystal requires development ad-hoc structures. The measurements are characterised in [] GHz band.

This phase shifter with agile frequency will be integrated into an antenna network and will be used to control the radiation pattern of the synthesised array antenna. In this paper, we propose two electrical models of carpet and gasket Sierpenski patch antenna. In our approach, we replace the antenna structure by its equivalent rectangular patch. Then, we build the electrical model in which we extract the resonant circuit RLC parameters. Return losses of the models are compared to physical patch for frequency band [1GHz, 3GHz].

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Simulation results given by our approach, show that the antenna and its model have the same resonant frequency at 2. A rigorous full wave technique based on the transverse wave concept iterative procedure WCIP is used to design and model a microwave active Screen. This approach takes the advantage of the combination of the rectangular and periodic waveguide modes.

Dec Signals, Circuits and Systems, This paper presents the effects of mutual coupling between the elements of an array, Mutual coupling between antenna elements can distort array pattern and increase reflected power to antenna feed system, To examine these effects in microstrip antenna arrays with 3times4 Butler matrix, prototypes of multilayer slot coupled and the Butler matrix were simulated.

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Furthermore, a four-antenna array was also designed at 12 GHz and then connected to the matrix to form a beamforming antenna system. As a result, three orthogonal beams at deg, 25deg, and 0deg are produced. A novel design of photonic band gap by F. The study of the photonic one-dimensional structures gaps was approached by several methods of analysis such as the FDTD, the method of the flat waves.

Our innovation in this study consists in using the iterative method based on the concept of wave FWCIP which establishes a relation of recurrence between the waves incidents and the waves reflected to see the electromagnetic behaviour of the dielectric one-dimensional structures And by calculating the coefficient of transmission and reflection, a comparison will be made at the level of these two coefficients with those found by means of the method of the FDTD. Dec Conference on Sciences and Techniques of Automatic control and computer engineering.

It is demonstrated that the integration of EBG structure reduces the unwanted mutual coupling between array elements and interfaces with on board systems. The principle of the iterative method consists of establishing a relationship between incident and reflected waves in order to characterize the studied structure. A technique of coupling pixels-mode is introduced to model vertical connections used in EBG structure.

The reflected and transmission coefficients are determined. The numerical results are compared with published data. The work presented in this paper refers to the synthesis of the radiation pattern of intelligent antennas by the artificial neural networks ANN based on linear antennas array supplied with coaxial lines. The method of synthesis implemented for this type of antennas makes it possible to approach with an optimal desired radiation pattern specified by a gauge with modifying amplitude, phase excitation and sources space distribution.

The approach used is based on geometry of the antennas and the artificial neural networks ANN which are able to model the linear antennas array. Our principal contribution in this paper is the extension of a synthesis model of the radiation pattern. The developed synthesis is based on the neural networks technique. Modeling of passive and nonlinear microwave structures using temporal iterative method.

In this work, we made the extension of the initially frequency method to the study of the structures in the temporal domain. This passage is guaranteed by adding a FFT algorithm.

Initially, this method is used the study of a microstrip line excited by Gaussian signal. Them, it is prolonged with the non linear lines. The good agreement between simulations and referenced data justifies the design procedure. Multi-users system technology, array processing and space-time beamforming are recent methods invented for wireless communication schemes. We treat in particular the capacity of multi-users detectors using beamforming technology.

At this stage, a new mathematical formulation in terms of capacity for various space-time beamformers is developed in this work. Analysis of an EBG filter using an iterative method. In this paper, we present an iterative method for analyzing electromagnetic band gap structures based on periodic via holes array.

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The method is based on wave concept using an iterative way with FFT algorithm. The operator of reflection in spectral domain is determined using the impedance of the via hole. The simulationpsilas result found and compared with a bibliographic reference is encouraging. Nov Signals, Circuits and Systems, This paper present the solution of the vector wave equation by a discrete time domain finite element method, based on the New Reduction meshing in three dimension RM-FETD reduction meshing-finite element time domain. These techniques allow obtaining a fully explicit time integration procedure.

The sampling rate of the time domain waveform is governed by the Nyquist rate of the Gaussian test signal instead of the carrier signal in the unconditionally stable RM-FETD method. Compared to the traditional FETD, the cost can be dramatically reduced when the test signal and carrier ratio is very small. This technique is implemented to solve a microwave guided structures. Numerical formulations are presented and simulations are compared with the normalize simulator. Optimal algorithm for the numerical inversion Laplace transforms method in a multiconductor transmission line system.

Aug Systems, Signals and Devices, The idea consists in studying the two well used algorithms in NILT, one is called quotient-difference algorithm using expansion of the Fourier series and the other is called epsiv-algorithm using the expansion of Laguerre function, in order to reach an optimal algorithm of the NILT method for different multiconductor transmission line MTL systems. The simulation results show that the quotient difference algorithm is most efficient than the epsiv-algorithm in term of rapid convergence to zero with a low relative error; these performances increase significantly the use of Laplace transform inversion by the method of Laguerre in MW circuits.

General synthesis method for linear phased antenna array. An efficient phase-only control method is presented to synthesise directive lobe and multilobe patterns, and create adaptive nulls in interference direction. The proposed method is based on iterative minimisation of a function that incorporates constraints imposed in each direction with respect to excitation phases. These structures are used as filters and reflector antenna as well as deep-space exploration for multi-frequency operations.

In order to initialize the iterative procedure, an incident wave is defined in spatial domain with arbitrary angle of incidence. The numerical complexity is studied and compared to the classical MoM. The good agreement between simulated and published data justifies the design procedure. May Information and Communication Technologies: From Theory to Applications, An efficient iterative technique based on the concept of wave is presented for computing periodic substrates in multilayer configuration once they are very important for Frequency Selective Surfaces applications.

In order to validate our theory, we intend to study periodic dielectric substrates in multilayer configuration. The approach involves the mixed magnetic and electric field equation technique and wave concept iterative process for the analysis of periodic planar multilayer substrates which involves S-parameters extraction technique based on a simple form of matched load simulation.

The numerical results are compared to published data. Good agreement will be important to establish the validity and usefulness of the iterative method given in this paper. This paper presents an implementation of an iterative method based on the wave's concept, for analysing a ring resonator. This method includes a two-dimensional fourier modal transformation 2D-FMT in a wave guide environment. The method has the advantage of simplicity in that it does not involve basis functions and inversion of matrices, as used in other calculation methods.

Therefore, it is capable of analyzing larger bodies than other classical techniques. An implementation of the iterative calculation is shown for the extraction of S parameters of microwave components. The good agreement between simulation results and experimental published data justifies the design procedure and validates the present analysis approach. Jan Microelectronics, This paper treats the crosstalk between strip lines using the classical theory of multi-conductor transmission lines MTL in a homogeneous medium. The extraction of S parameters theoretically by MTL method and by simulation with advanced design system momentum software ADS give almost the same characteristics.

Also an investigation has been made on the dependence of the crosstalk according to different values of the substrate dielectric permittivity and the height of the substrate showing that there is an optimum value of these parameters for less crosstalk. Study of the antennas array configuration impact in the localization of sources. The localization of angular positions of sources is a very promising topic in wireless communication systems.

Many algorithms for the estimation of angular positions using an antennas array have been investigated from the beamformer methods to the high resolution methods MUSIC, Propagator The introducing of subspace methods have ameliorate the quality of estimation with a infinite resolution, but, until now, a limited number of works has interest in the importance of the configuration of the antennas array and its impacts on the estimation process. But, for the 2-D azimuth and elevation DOA estimation problem, at least a planar array is required. In this paper we will study different geometry configurations of planar antennas array in the estimation of 2-dimensional direction of arrival and we present a new 3 dimensional antennas array that will ameliorate the resolution of the MUSIC algorithm.

We will show the effectiveness in relation to the other shapes of arrays generally used as the circular and planar arrays, especially for the 2-D estimation of direction of arrival azimuth angles and elevation angles. We will also discuss the concept of phase modes, which is a useful tool for the understanding of the performance of circular arrays. It is also used in pattern synthesis.

Omnidirectional patterns will be studied in some detail, especially the problem of reducing the amplitude ripple. Successful applications show that the approach can be used as a general tool for pattern synthesis of circular antenna arrays. All the design is based on the use of a Lange coupler with certain geometrical characteristics. Simulation results of magnitude and phase show a good performance. Furthermore, a four-antenna array was also designed at 2. This matrix is suitable for wireless application at ISM band of 2.

A new estimation of direction of arrival algorithm with a special antenna shape. This paper presents a new subspace-based 2D direction of arrival DOA estimation algorithm for narrow-band sources with high-resolution localization capabilities. DOA estimation is achieved by using the noise-subspace eigenvectors of a new extended correlation matrix ECM. A 2-L-shape antenna array is proposed. Unlike common planar and circular arrays, the novel antenna array with this special geometry requires no pair matching between the azimuth and elevation angle estimation.

The performance of the proposed approach is examined by a simulation study in the presence of multiple wave fields. The simulation results show a good estimated performance of the proposed method. Utilisation des composantes longitudinales dans les circuits multicouches: Modeling of planar multilayer periodic arrays using iterative method. A global electromagnetic modeling of an active Microstrip structure. This article presents a new technique that uses the auxiliary sources for investigation of structures including nonlinear components. The numerical results are compared with published data and a good agreement is observed.

Patch antennas plane networks have been used largely in communication systems. Their capability to change radiation pattern electronically, multi-beam capacity and high spatial resolution has made them attractive for mobile communication applications. The work presented in this paper refers to the synthesis of periodic patch antennas plane networks supplied with coaxial lines. The method of synthesis used for this type of networks let's possible an optimal approach for the desired radiation pattern specified by a gauge sensible for source excitation and space distribution of the radiant sources.

The development of the synthesis is based on the neural networks technique. In this paper, we intend to study the synthesis of the multibeam arrays. The synthesis implementation's method for this type of arrays permits to approach the appropriated radiance's diagram. The used approach is based on neural network that are capable to model the multibeam arrays, consider predetermined general criteria's, and finally it permits to predict the appropriated diagram from the neural model.

Our main contribution in this paper is the extension of a synthesis model of these multibeam arrays. The transverse wave concept iterative procedure is presented for full wave investigation of MEMS capacitive switch. Using the transverse wave approach we can reduce the number of interfaces in planar circuit by the introduction of adequate boundary conditions. The circuit plane includes four subdomains: The switch subdomain is characterized as a lumped element model in the two states that are on and off. Taking use of the major advantages of the wave concept iterative procedure method offered by the developed fast modal transform FMT , which is based on the 2D-FFT algorithm, minimum computation time, and less memory, is needed to calculate the scattering parameters of the switch.

Two different MEMS switches are studied that are the cantilever and the air bridge. The simulated results for these examples show very good agreement compared with those obtained by other methods. Apr Positioning, Navigation and Communication, This paper presents a new subspace-based 2D direction of arrival DOA estimation algorithm for narrowband sources with high-resolution localization capabilities. A 2-L shape antenna array is proposed. Unlike common planar and circular arrays, the novel antenna array with this special geometry requires no pair matching between the azimuth and elevation angle estimation also this key can remove the drawbacks of estimation-failure problems.

The performance of the proposed approach is examined by a simulation study. The simulation results show a good estimate performance. Jan Electronics, Circuits and Systems, This paper presents a generalized and easy to use method based on Hill's equation to analyze the electromagnetic wave propagation in stratified dielectric or in inhomogeneous media with arbitrary permittivity profiles.

The purpose of this study is to explore the effects of polarization, incidence angle, layers thickness, and permittivity profiles on reflection and transmission characteristics. Due to the analogy which exists between antireflection and frequency selective surfaces, a general purpose computer program was written to incorporate the whole mechanisms of reflection and transmission in order to analyse and design multilayer antireflection coatings as well as frequency selective structures.

Obtained results agree well with published data. Direction of arrival estimation method using A 2-L shape arrays antenna. The paper presents a new algorithm for a 2-dimensionnal direction of arrival estimation.

Based on the extended Kalman filter EKF , we analyse a recursive procedure for 2-dimensional directions of arrival DOA estimation and we will employ the two-L-shape arrays. A new space-variable model which we call a spatial state equation is presented using array element locations and incident angles. In this paper we briefly recapitulate the most important features of the extended Kalman filter EKF.

The performance of the proposed approach is examined by a simulation study with three signals model. Application of neural network to the synthesis of linear antenna array's radiance diagram. In this paper, we intend to study the synthesis of the linear antenna arrays. The synthesis implementation's method for these type of arrays permits to approach the appropriated radiance's diagram. The used approach is based on neural network that are capable to model the linear antenna arrays, consider predetermined general criterias, and finally it permits to predict the appropriated diagram from the neural model.

Our main contribution in this paper is the extension of a synthesis model of these arrays' radiance diagrams.

Analysis of tunnel diode antenna using iterative method. An efficient iterative method, based on the wave concept has been used to analyze the printed tunnel diode integrated antenna. A high computational speed has been achieved by introducing a 2D fast Fourier transformation 2D-FFT in wave-guide environment.

The simulated results are compared with published data and a good agreement is observed. This paper proposes a computationally efficient method for a two-dimensional direction of arrival estimation of multiple narrowband sources. This paper will employ two L-shape arrays that showed better performances than the one L-shape and the parallel shape arrays. In spite of its computational complexity, simulation results verify that the proposed subspace technique gives much better performance than the propagator method.

Analysis of planar circuit using a multigrid iterative method. RF propagation mechanisms in arbitrary inhomogeneous slabs. Understanding propagation phenomena in inhomogeous media plays a significant role in passive and active components design. Common applications include, but are not limited to, high quality resonators, transmission lines, linearizers, absorbers and frequency selective surfaces FSS.

The aim of this paper is to assess the behaviour of electromagnetic waves in inhomogeneous media with arbitrary profiles in order to derive pertinent quantities such as the reflection and transmission coefficients which constitute a true representation of the propagation mechanisms. The Hill's equation features and Floquet exponents' extraction were used to perform all simulations, numerically. Analysis of DGS structures by using iterative method. An iterative method based on the wave concept is used to analyse a defect ground structure DGS. In this case two applications are given.

Secondly, a newly etched DGS with a spiral shape in metallic ground is studied. The spiral DGS can provide steep rejection characteristics with one and two spirals. Numerical results are compared with published data, a good agreement is observed. An efficient iterative method based on the concept of waves is presented to determine the characteristics of coplanar waveguide CPW and the finline step discontinuity.

A two-dimensional fast Fourier transformation algorithm is introduced to simplify calculations and accelerate the convergence with reduced central processing unit time. The general formulation and implementation procedure of the method are described. The numerical results are compared with the published data obtained by other methods.

This comparison shows a good agreement. Signaler Commenter la réponse de dany Commenter la réponse de dany Signaler Commenter la réponse de Ben Ben Messages postés lundi 12 décembre Date d'inscription 1 mai Dernière intervention - 11 nov. Commenter la réponse de Ben Signaler Commenter la réponse de Aranud Aranud87 Messages postés dimanche 29 octobre Date d'inscription Contributeur Statut 15 août Dernière intervention - 8 avril à Afficher les 6 commentaires.

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