GEO Satellite Regional Coverage Multibeam Antenna Design And Performance Analysis

Satellite communication has its irreplaceable position in communications inemergency, airplane, distant sea as well as the places where terrestrial cellularcoverage cannot reach. In recent years, China has an increasingly demand forbroadband multimedia satellite communication. As a key technology, multi-beamantenna can increase the antenna gain substantially by using spot beam instead ofglobal beam, thus can support the small satellite terminals and increase thesystem capacity. Meanwhile, frequencies can be reused between different spotbeams, which improve the frequency utilization. However, the satellitemulti-beam antenna technology is still in its infancy in China. Lots of problemsneed to be solved. This article aims to analyze the satellite multi-beam antennadesign and coverage performance under GEO scenario, and to promote thedevelopment of multi-beam antenna technology.This paper mainly discussed the satellite multi-beam antenna design andcoverage performance under GEO scenario, including three aspects as follows:Firstly, in order to meet the demand of covering mainland China seamlessly, atype of hexagon honeycombs structure of beam distribution is designed. Thecorresponding latitude and longitude coordinates of the spot beam center areprovided, and the coverage performances of the design are verified.The coverageperformance of two different beam widths are ayanalized. The optimized41-beamcoverage pattern can cover mainland China seamlessly. And the gain increased by10dB compaired with globlal beam.Secondly, the paper designed a reflecting surface multi-beam antennaaccording to parameters such as beam width and operating frequency. A novelprinted Yagi unit fed multi-beam dielectric sphere lens antenna is proposedthrough simulation and testing. This multi-beam antenna is of small size, lightweight, which is applicable to satellite mobile communication system.Finally, the performances of adaptive beamforming algorithms are discussedin satellite communications. Based on the concept of "single-beam single-user",we set an antenna array of high complexity. Conjugate gradient, conjugate gradientdiagonal loading, auxiliary vector and the minimum mean square error algorithmare analyzed about convergence rate and performance. At last the idea ofground-based beam forming network system is conveyed.