Unique attenuation characteristics of ku-band Lune-Q antenna for Satellite retransmission of terrestrial digital broadcasting signal

This paper deals with the unique low rain attenuation characteristics of the Lune-Q antenna, which is used in the satellite retransmission system for terrestrial digital broadcasting CTV signal by using the 14/12 GHz band transponder. To achieve the optimum design of the satellite retransmission system of terrestrial CTV signal, propagation experiments to determine the propagation characteristics and confirm the satellite digital broadcasting CTV transmissions service quality confirmation were carried out in 2006, between the JSAT Yokohama Satellite supervisory and control station (JSAT-ES) and Hokkaido Institute of Technology (HIT) earth-station (HIT-ES). During the propagation experiments, it was found that the Lune-Q antenna rain attenuation characteristics are superior to those of the conventional parabolic antenna, i.e., small rain attenuation values. The rain attenuation values of conventional parabolic antenna and the Lune-Q antenna were compared, for the period from April to October 2006. It can be observed that rain attenuation values of the Lune-Q antenna were about 1/10 times lower. The small rain attenuation characteristics are considered to originate due to reasons such as multi-path reception by the Lune-Q lens characteristics, the feed horn position, and polarization effects, etc.