by Murat Celep
In the wide band radiometer, it is necessary to use more than one low noise amplifier (LNA) because of their narrow band characteristic. The change in the gain of the LNAs with different frequency ranges was kept at minimum value by continuously terminating the LNAs’ ports with a load whose impedance is equal to impedance of match load. Thus, in order to perform the noise measurements of solid state microwave noise sources between 50 MHz and 26.5 GHz frequency range at a time, a wide band radiometer was established. The calculated ENR uncertainties for measurements done by the radiometer are lower than 0.34 dB (k=2).