Amor Smida

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

Hybrid MUSIC Dolph-Chebyshev algorithm for a smart antenna system

This paper presents practical design of a smart antenna system based on direction-of-arrival estimation and Dolph-Chebyshev beam forming. Direction-of-arrival estimation is based on the multiple signal classification algorithm for identifying the directions of the source signals incident on the sensor array comprising the smart antenna system. The smart antenna system design involves a hardware part, which provides real data measurements of the incident signals received by the sensor array. This paper presents the Dolph-Chebyshev method for the synthesis and design of antenna arrays with periodic element spacing. A Field-Programmable Gate Array implementation is presented for an antenna array application employing digital beamforming. The array comprises 10 elements, equal in number receiving radio frequency and intermediate frequency components, as well as a Spartan-3E Field-Programmable Gate Array-based unit, which is responsible for the control of the array. Low-cost and switched-beam, and fully adaptive antenna array suitable for 2-GHz applications are proposed in this paper. 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.

A 4 bits Reflection type phase shifter based on Ga As FET

A 4 bits digital phase shifter is designed and simulated. It is based on 3-db hybrid coupler and totally twelve switches are used. The simulation results indicate an insertion loss better than -4dB, a return loss less than -20 dB and an error phase varied between 0.01° and 0.6° at 2.45 GHz. to achieve a 6 bits phase shifter, we increased the number of stages. This phase shifter present an insertion loss better than -5dB, a return loss less than -20db and an error phase varied between 0.1° and 1.7°. But, the circuit presents a large size. The Ga As FET switch used for switching is characterized by a very low DC power consumption, a fast switching speed and a low cost. Also, an array antenna of 8 patch elements connected to a 4 bits phase sifter is designed. The simulated results of the array indicate a return loss better than -10dB over 2.4-2.5 GHz and a gain equal 14 dB.

Concentric ring array synthesis using Taguchi algorithm for MIMO applications

In this paper, we study an electromagnetic optimization technique using Taguchis method and apply it to concentric ring antenna array design. Taguchis method was developped on the basis of the orthogonal array (OA) concept, which offers systematic and efficient characteristics. The newly proposed idea is the implementation of Taguchi optimization method for Concentric Circular Antenna Array (CCAA). The optimization procedure is then used to provide an optimum set of weights for different CCAAs. Obtained results show that the desired radiation pattern with optimum sidelobe level (SLL) reduction is successfully achieved. The numerically simulated patterns are obtained and compared with those of concentric circular isotropic arrays (12, 18, 24, 30 and 36 elements). Compared to traditional optimization techniques and well-known algorithms (Evolutionary Programming (EP) algorithm and Firefly Algorithm (FA)), Taguchis method is easy to implement and efficient to reach the optimum solutions.

Design and analysis of a microstrip antenna array for biomedical applications

Breast cancer affects many women all over the globe and means for early detection are necessary for fast and effective treatment. Mammography, which is currently the most popular method of breast screening, has some limitations and microwave imaging seems to offer a good alternative. In this paper, a study of patch antenna array for breast cancer detection is presented. The results show that the proposed antennas design is capable of detecting the breast tumor with much improved characteristics compared to the other designs available in the literature. The capabilities and limitations of this antenna for detecting tumor models are investigated through simulations and its potential for detecting tumors in the breast is highlighted.

Circular antenna array design for breast cancer detection

Microwave imaging for breast cancer detection is based on the contrast in electrical properties of healthy fatty breast tissues. This paper presents, an industrial scientific and medical bands (ISM) comparative study of five microstrip patch antennas for microwave imaging at 2.45GHz frequency, a choice of one antenna is made for an antenna array composed by 8 antenna for a microwave breast imaging system, each element are arranged in a circular configuration, so as that every antenna element can be directly faced to the breast phantom for better tumor detection. This choice was made by putting each antenna alone on the Brest skin to study electric field, magnetic fields and current density in the healthy tissue of the breast phonton designed and simulated in Ansoft High Frequency Simulation Software (HFSS).

Beamforming multibeam antenna array using Taguchi optimization method

In this paper, an efficient method is presented to synthesize directive beam and multi-beam patterns. 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 beamforming towards any desired direction The results of Taguchis method are validated by using array antenna patch and simulated by software CST2013 (CST microwave studio).

Synthesis of phase of conformal cylindrical arc antenna arrays referring to taguchi method

This paper presents a new approach to synthesize conformal cylindrical antenna arrays by controlling the phase excitation, to create a directive lobe using Taguchis method. The aim of our proposed method consists on the minimization of the fitness function between obtained and desired results. The results found, with the application of this method to synthesize conformal cylindrical arc antenna arrays, are validated with simulation by CST Microwave. We have used CST Microwave to simulate an 8-element conformal cylindrical arc antenna; witch has been tested in variable types of beam configurations.

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)