A document by Bilel HAMDI. Click on the document to view its contents.

Radiation pattern of cylindrical antenna array is one of the most important problem in communication applications. This paper describes the synthesis method of cylindrical array radiation pattern in adaptive beam forming by using the neural network. Synthesis examples with three-dimensional cylindrical conformal arrays are presented. An uniform circular array (UCA) antenna (as a basic element) mounted on empty coated cylinder array antenna, respectively, a concentric circular array (CCA) antenna that similary mounted on fully multilayered coated cylinder array antenna (with a many cylindrical layers), are considered and its theoretical accurate solutions of pattern synthesis are derived. Moreover, we show by means of simulations implemented in Matlab that the method is applicable to cylindrical conformal array. The used neural technique proved its effectiveness in improving performance using the cylindrical isotropic antenna array. Some examples are calculated. The proposed method can also be useful for other kinds of conformal phased arrays such as spherical or conical configurations.

In this paper, a new conformal array antenna conical design has been proposed. It can electronically steer the main beam in azimuth and elevation to cover a hemispherical mesh surrounding the given antennas configuration. To achieve the desired beam configuration, it is absolutely essential to select the appropriate antenna control parameters. To this aim, the optimization of the neural technique is adapted to the optimal set of matching parameters. For more details, this work discusses the use of an efficiently designed artificial neural network (ANN) to model and synthesize the radiation pattern of an adaptive uniform cone lattice beam. Let's assume, then, that the learning database of the network has a finite number of target selections at certain feasible angles. Utilized a feedforward artificial neural network model called a multilayer perceptron (MLP), generates a set of appropriate outputs based on sets of input data. The obtained systems are performed in Matlab and the suggested conforming conical array shows a significant enhancement versus the existent structures in terms of 3-D scanning, size, directivity, HPBW and SLL reducing. The employed neural technique revealed its effectiveness in improving performance using the conical isotropic antenna array. To approve this work, several examples are shown. The proposed method can also be utilized for other kinds of conformal phased arrays such as spherical or cylindrical arrangements.

Symmetries play an essential role in the field of physics. In this paper, we examine the relationship between the eigen-amplitudes of 4 symmetrical antennas and the symmetry of the amplitudes of their sources (excitations) using mirroring effects. By exploiting the symmetry problem, we can show the advantage of reducing the size of the analysis domain, at least by a factor of two or more (2,4 and 8)(depending on the problem). Several simulation examples have been developed by the MoM-GEC and HFSS to validate this approach.