Study Of Beamforming For Base Station Antennas And Its Application

With the large-scale commercial use of the third generation mobile communicationtechnology (3G) and the commercial trial of the fourth generation (4G), the base stationantennas face increasingly stringent requirements on the performance of transmissionspeed and data quality. Since the traditional omni-directional antennas and clusterantennas cannot meet the requirements, the application of antenna arrays in base stationattracts more and more attention in recent years. With the significant advantages of highgain, strong radiation directivity, ease of beamforming and good performance ofanti-interference, the antenna array has become a research hotspot in antenna study anddesign. Therefore the design and optimization of beamforming for antenna arrays attachgreat importance, which are the key technologies of antenna arrays. The thesis mainlystudies one of the algorithms used for beamforming of antenna arrays on base station.Its major work includes the following aspects:A brief study on two traditional approaches and several popular optimizationalgorithms for pattern integration has been made. And the principle and strategy offirefly algorithm (FA) are elaborated. In the paper, we consider the beamformingproblem as an optimization task of a constructed objective function. Based on FA, thethesis ultimately realizes a novel method of beamforming of base station antennas.An optimization software for beamforming is developed, which adopts FA as itscore algorithm. Then sorts of special beams matching the certain requirements of basestation have been designed and realized by using the software, which includes narrowbeam, wide beam, saddle beam, horizontally-tilted beam and vertically-tilted beam, etc.Besides, the tasks of null-fill and sidelobe suppression have been completed.A wideband planar dipole array has been designed, by which the beamformingsoftware in this paper has been tested by comparison of the radiation patterns fromsoftware and from simulation based on HFSS. The single element of the array adopted afolded dipole structure, whose arms are coupling fed through a50ohm coaxial feeder.The antenna is printed on the dielectric plate with a thickness of1mm and a relativedielectric constant of2.65. It works in the frequency band from2.3to2.8GHz. Thensixteen elements are arranged to become a4*4antenna array with an x-axial space of82mm and a y-axial space of61mm. The array works in the frequency band from2.5to4.3GHz. The thesis takes the single element and the1*4array as two sets of arrayelements, and verifies the pattern integration results of E-pattern of1*4array and H-pattern of4*4array respectively. The testing results illustrate the efficiency andaccuracy of the software.