Spectra of Plasma Relativistic Microwave Amplifier of Monochromatic Signal

The ratio of the radiation energy of the plasma relativistic microwave amplifier at a frequency of the input signal to the noise energy is measured. In the absence of the input signal, the noise radiation is detected. It is shown that, under certain conditions, the amplifier noise energy sharply decreases, as compared to the noise energy measured in the absence of the input signal.