A compact highly sensitive radiometer for thermal sounding of atmosphere in 5 MM band

Design and characteristics of a compact highly sensitive direct detection MMIC radiometer of 5 MM wave band with a goal of atmosphere temperature profile determination are presented. The radiometer has bandwidth 56.6 plusmn 0.25 GHz and fluctuation sensitivity 35 mK/Hz
^1/2
/65 mK/Hz
^1/2
in a ldquototal powerrdquo/modulation mode. The radiometer was successfully used for atmospheric temperature profile measurements with the thermal sounder MTP-5. Average deviation of a measured atmospheric temperature profile from the temperature profile constructed according to 11 probes was 0.2 C-0.4 C, average mutual difference of two devises was equal to or less than 0.2 C.