Design and characterization of a low noise amplifier operating at cryogenic temperature

This paper presents the design and test results of a low noise amplifier indigenously developed for VECC cryogenic Penning ion trap facility. The amplifier is built in two stages of which the first stage provides signal amplification whereas the second stage offers an output impedance of 50 Ω. The voltage gain as well as input voltage noise density of the amplifier is measured at room temperature and 130K. In this paper, we have demonstrated that cooling the amplifier down to 130K increases the voltage gain by a factor ∼ 1.5 and decreases the input voltage noise density by a factor ∼ 1.7.