Edson R. Schlosser

Synthesis of linear antenna array for 4G mobile communication systems

This paper presents the application of optimization methods for the synthesis of a linear array to operate in the frequency range of 4G technology in Brazil. The desired pattern shall exhibit squared-cosecant shape, so as to provide uniform distribution of power inside the base station cell and to reduce co-channel interference. Such an array is well suited to operate as a radio base station of mobile communications systems. The synthesis is performed by a combination of optimization methods: the genetic algorithm, which is used for the initial global search, and the sequential quadratic programming, which is applied for local refinement of the solution. This approach allows faster convergence than using only one kind of optimization method. The technique is demonstrated for a linear array of isotropic elements and, subsequently, for an array of E-shaped microstrip antennas.

Synthesis of linear antenna arrays for radio base stations

This paper presents the application of optimization methods for the synthesis of a linear array for radio base stations of mobile communications systems. The desired pattern shall exhibit squared-cosecant shape, so as to provide uniform distribution of power inside the base station cell and to reduce co-channel interference. The synthesis is performed by a combination of optimization methods: the genetic algorithm is used for the initial global search, then the sequential quadratic programming is applied for local search. This approach allows faster convergence than using only one kind of optimization method. The technique is demonstrated for a linear array of isotropic elements and, subsequently, for an array of microstrip antennas.

Particle Swarm Optimization for antenna arrays synthesis

This paper presents the application of optimization methods to synthesize the radiation pattern of linear antenna arrays. The performance comparison between Particle Swarm Optimization (PSO) and Genetic Algorithm (GA) to obtain different pattern shapes is realized. The techniques are applied for a linear array of isotropic elements, and, subsequently, for a microstrip array.

Linear Array Design with Switched Beams for Wireless Communications Systems

This paper presents an analysis for optimal design of switched beamforming applied to a linear array for wireless communication systems. The beam switching scheme provides coverage of a given sector in azimuth and controls the sidelobe level simultaneously. The analysis was developed considering arrays composed of Quasi-Yagi elements. The model assumes a user moving in the azimuthal direction under a constant velocity and with an estimation of the signal-to-noise ratio (SNR) at the mobile user (MU). The radio base station applies the beam that yields the best performance during transmission. The decision is based on the feedback information received from the MU. The goal of the analysis is to determine the best trade-off between the array size and number of feedback bits necessary to maximize the SNR at the receiver. The results show that a compromise between the number of beam-pointing directions and the array size should be taken into consideration for a wireless communication system design.

Optimization of switched-beam arrays for communication systems

This paper presents the application of optimization methods for the synthesis of a linear array for communication systems. By means of suitably beam switching, the array should provide coverage of a given angular area in azimuth and should allow controlling the sidelobe level simultaneously. For this purpose, two optimization methods have been used to calculate the excitation coefficient for each desired beam. The synthesis technique is demonstrated for arrays composed of isotropic and microstrip elements. By comparing the results obtained for both arrays, the need of consideration of the array element pattern during the synthesis process is demonstrated.

Beam-shaped radiation pattern for uniform radiated power distribution

This paper presents the application of optimization methods for the synthesis of antenna arrays. The desired pattern shall exhibit a shape that allows uniform distribution of the radiated power on the Earth. Besides beamshaping, the optimization methods allow controlling the level of the sidelobes. The synthesis technique is used to calculate the excitation coefficients for arrays composed of cavity-backed circularly polarized annular slot antennas.