Study of 21-GHz-band Rain Attenuation Based on Annual Observations of Broadcasting Satellite Signals

We have been conducting research and development of 21-GHz-band satellite broadcasting using the BSAT-4a broadcasting satellite. We have studied the rain attenuation characteristics of the 21-GHz band using annual observations of signals from the BSAT-4a at Tokyo, Japan. We discuss the differences between the measurements and the predictions of the ITU-R model with a measured rainfall rate.