Sistema para medição da atenuação devido à chuva em enlaces de satélites na banda Ku

Abstract

Among the several impairmentes suffered by an RF satellite signal above 10GHz , the attenuation due to rain, is which causes the most significant and detrimental effect. This attenuation requires reserving a considerable margin in the system project; which leads to increase in power, the use or larger antennas or complex error correction techniques, consequently, leading to increased costs. This work describes the design, construction and operation of a receiving system in the Ku / Ka band to measure, date and store the instantly value of both the attenuation and the rain rate, in order to build a database, which allows to study and compare the data obtained the light of the theoretical models used in the projects. The system has a parabolic antenna 4.2 m in diameter with angular movement in elevation and azimuth axes using electric motors, a station for collecting environmental data and an unmodulated carrier receiver (beacon). The antenna was designed to allow a measuring range up to 28dB of attenuation in the signal, considering the typical transmitted signal levels of the satellites currently in geostationary orbits.