AN ESTIMATION OF S N DEGRADATION AT MILLIMETER WAVES DURING RAIN EVENTS/

The use of Ka Band (20/30 GHz) for future satellite communications has been addressed. The exploitation of Ka band with a bandwidth of 2500 MHz seems to represent the largest significant achievement in satellit e communications potential, so far. The problems associated with the u se of this frequency band such as attenuation and receiver with the us e of this frequency band such as attenuation and receiver noise temper ature (floor) variation with rain has been addressed. The receiver noi se floor variation with rain has so far been ignored. Therefore, in vi ew of propagation and noise study over this Ka Band, both signal atten uation and receiver noise floor variations with rain rate are estimate d using dual frequency radiometers operating at 22.235 and 31.4 GHz ov er a tropical station, Calcutta, India.