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This study presents the study of beamforming capabilities of arrays installed on a non‐conductive unmanned aerial vehicle (UAV). The main purposes of this study are the application of a beamforming algorithm by including the airframe in the optimisations and the study of simplifications of the aircraft model, so as to allow performing full‐wave simulations, even though the UAV is much larger than the operating wavelength. To validate the simplified electromagnetic model, antenna arrays have been designed and installed onto the UAV. Radiation pattern measurements demonstrate that the proposed simplifications yielded very good radiation pattern predictions and can be used as guidelines for simulation of other kinds of non‐conductive aircrafts.

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.

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.

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