Hichem Trabelsi

Phased arrays in communication system based on Taguchi-neural networks

Phased antenna array design is one of the most important electromagnetic optimization problems. This research combined the Taguchi method and artificial intelligence methods, used them as the prediction tool in designing parameters for the communication system, and then constructed a set of the optimal parameter analysis flow and steps. In this paper, we present an application of artificial neural networks in the electromagnetic domain. We particularly look at the multilayer perceptron network, which has been the most used of artificial neural networks architectures both in the electromagnetic domain and in the Taguchi optimization technique and describes the Taguchi method to optimize the excitations elements of the linear array to produce a radiation pattern with minimum side lobe level and null placement control. This paper investigates how the implementation of the signal processing in hardware affects the performance of the adaptive array antenna. The investigation is confined to uplink or receive antenna array only. Results of a prototype of antenna array with feeding values designed using the proposed techniques are also presented. Copyright

Phase-only array beam control using a Taguchi optimization method

This paper introduces the developed hardware platforms of the smart antenna transmitter system and its implementation details and presents the novel concept of smart antenna system which requires digital beamforming based on Taguchi Method. This paper investigates how the implementation on STM8 of the signal processing in hardware affects the performance of the adaptive array antenna. This system shows excellent performance for the radiation pattern and capable to steering by adjusting the relative phases of the signal received or transmitted by each antenna. The objective of the design is to construct smart antenna beamforming systems with hardware-software implemented Taguchi Method.

Phased uniform linear antenna array synthesis using genetic algorithm

This paper describes a new method for adaptive beamforming for a phased antenna arrays using genetic algorithm. The algorithm can determinate the values of phase excitation for each antenna to steer the main beam in specific direction. Various results are presented with −10 dB side lobes level. To improve these results, a Chebyshev model was proposed in order to decrease the level of side lobes which consists in amplitude synthesis.

Analyzing of one dimensional quasi periodic circuit by using auxiliary sources in a WCIP method

A new approach of the iterative method WCIP (Wave Concept Iterative Process) using the technique of the auxiliary sources considers a pixel or a unit cell in a periodic structure as an electrical circuit instead of a sub-domain representing metal or dielectric in the classical iterative method. The intersection of this new approach with the old is on the application of the iterative process in waves between the space and spectral domains in order to calculate the electric field and the density of current. The novel approach is introduced by the study of two types of defects on an uniform transmission line. The first one is a defect of a resistance, the other is a defect of a reactance. The results of simulation of the variation of current along the transmission line are agree with the theory which validates our proposed approach.

Analysis of planar microwave structures using transmission line-periodic lumped circuit by an iterative method WCIP

The theory of a novel approach of the WCIP method to analyze periodic lumped circuits has been presented. Transmission lines in their planar form (microstrip technology) can be modelled by an equivalent periodic lumped circuit that permits a fast analysis instead of the use of many electromagnetic full wave simulators which require a great running time and great memory size. The validation of the proposed approach was made by comparing the results of simulation with ADS simulator of a bandpass filter designed in its planar form and equivalent periodic lumped circuit.

Adaptive radiation pattern optimization for antenna arrays by phase using a Taguchi Optimization method

In this paper, an optimal radiation pattern is obtained for a linear antenna array using Taguchis Optimization method. A set of phase shift weights are generated in order to steer the beam towards any desired direction. The fitness function is used to calculate the phase shift weights. The results of Taguchis method are validated by using array antenna patch and simulated by software CST2009 (CST microwave studio)