Summary: | 碩士 === 元智大學 === 通訊工程學系 === 101 === With the development of broadcasting satellite communication service, requirements of communication traffic and bandwidth are increasing. This thesis research is to design a direct broadcasting satellite feeding elements, operated at Ku- and Ka-band. Direct broadcasting satellite is widely applied in developed country, due to its convenience for set up, high level signal quality and uneasy to be interference by noise.
Since the development of satellite communications gradually tend to multi-band and multi-point signal transmission. In this thesis, corrugated horn structure is replaced by RF dielectric lens, for the design of a 2.5 GHz bandwidth linear-polarized lens antenna operated at Ku-band. By reducing the antenna size and maintaining the antenna radiation efficiency simultaneously, to increase the number of feeding antenna and expand applicable band in the same dish antenna system of satellite communication. Taken into consideration of the satellite communication toward to Ku- and Ka-band applications, the design of dual band horn antenna which can receive linear-polarized signal at Ku-band and circular-polarized signal at Ka-band. To achieve multi-band and multi-point communications in the same antenna structure.
In order to analysis maximum number of feeding antennas which is operated at Ku- and Ka-band, combining seven feeding antennas with a dish reflector. The radiation pattern and directivity are measured in an anechoic chamber. The maximum directivity can be achieved by adjusting the position of feeding antennas. All measurement results are met the requirement of satellite communication transmission.
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