A study on radiation pattern of on-board array-fed reflector antenna for direct broadcasting satellite

摘要

21 GHz-band satellite broadcasting is expected to be put into widespread use in broadband and multichannel broadcast services in the future. However, rain attenuation in the 21 GHz-band microwave is larger than that in the 12 GHz-band one. To overcome the attenuation, we have been studying a method to compensate for it by using an advanced broadcast satellite with an on-board large-scale phased array-fed reflector antenna. The satellite can compensate for rain attenuation by increasing e.i.r.p. over the areas in which rain is falling. This paper shows that the calculated radiation patterns with 40 dBi antenna gain for fine-weather areas are obtained. Also, for forming one or two compensation beams, the average gain for a fine-weather area is decreased by 1 dB. Moreover, when forming two compensation beams, a difference in gain of about 2 dB occurs between the two compensation beams.