Home › Content

Cryogenic ultra-low-noise SiGe transistor amplifier

Wed, 2012-03-21 22:07 - Lukas Hanschke
Printer-friendly versionSend by emailPDF version
Date: 
2011-10-25
Author(s): 

B. I. Ivanov, M. Trgala, M. Grajcar, E. Il’ichev, and H.-G. Meyer

Reference: 

Rev., Sci., Instr., 82, 104705 (2011)

URL: 

http://rsi.aip.org/resource/1/rsinak/v82/i10/p104705_s1?isAuthorized=no

An ultra-low-noise one-stage SiGe heterojunction bipolar transistor amplifier was designed for cryogenic temperatures and a frequency range of 10 kHz–100 MHz. A noise temperature TN ≈ 1.4 K was measured at an ambient temperature of 4.2 K at frequencies between 100 kHz and 100 MHz for a source resistance of ∼50 Ω. The voltage gain of the amplifier was 25 dB at a power consumption of 720 μW. The input voltage noise spectral density of the amplifier is about 35 pV/Hz^(1/2). The low noise resistance and power consumption makes the amplifier suitable for readout of resistively shunted DC SQUID magnetometers and amplifiers.