Study On The Analyses And Calculate Of Rain Attenuation Of Ka-band Satellite Communication System

With the development of millimeter-wave technology, a satellite communications application toward the band has a large capacity, high-frequency extension. Using Ka-band satellite communications is not only inevitable trend of China’s military applications, but also to the new high-speed satellite communications business provides a new means in civilian areas.For Ka-band satellite communication systems, due to its high operating frequency, signal attenuation caused by rainfall more serious. This paper analyzes the physical characteristics of rainfall include raindrop shapes, finishing speeds, rainfall intensity, size distribution, focusing on the mechanism of signal power attenuation due to rain; Secondly, the use of ITU-R recommendation of rain attenuation model, based on the distribution of climate Select the relevant parameters typical stations as calculated on the basis to calculate the local average annual rainfall of more than rain attenuation values of P%rate, the distribution characteristics of rain attenuation; again to small mobile satellite communication earth station as a platform to build rain attenuation test system, detailing the composition and principle of the test system, test system and measurement error is analyzed, in parts of our country through the Ka-band earth-the air line, the downlink signal rain attenuation test, reached a different signal attenuation rain rate case; Finally, the test results and the results were analyzed and compared, the results obtained and the practical significance of the test results in engineering applications, for the Ka-band satellite communication systems, especially small satellite communication earth station. The system is designed to provide a more accurate value basis.Research methods used in this paper has some limitations, this experiment with a small mobile satellite communication earth station based on the received satellite signal to noise ratio is not high, the limited dynamic range, while, by the time, funding constraints, the test area Time is limited, the measured value does not fully reflect the region’s long-term rain attenuation statistics feature in the latter work, will select additional areas related tests in order to obtain more test data for rain attenuation data supplement.