TY - JOUR
T1 - Analysis of the input noise contribution in the noise temperature measurements
AU - Hu, Shu-I
PY - 2005/3/1
Y1 - 2005/3/1
N2 - In measuring the noise temperature of a cryogenic microwave low-noise amplifier (LNA), the noise from the input thermal buffer, i.e., the coaxial cable that connects the noise source to the amplifier, needs to be correctly accounted for. With the amplifier's noise temperature approaching just a few Kelvins, the postulate used in calculating the cable's noise temperature, that the cable is homogeneous and has a linear temperature profile, commands a further inspection. This letter analyzes these assumptions and clarifies the situations in which they hold. To substantiate this Kelvin-level discretion, a LNA is designed and measured.
AB - In measuring the noise temperature of a cryogenic microwave low-noise amplifier (LNA), the noise from the input thermal buffer, i.e., the coaxial cable that connects the noise source to the amplifier, needs to be correctly accounted for. With the amplifier's noise temperature approaching just a few Kelvins, the postulate used in calculating the cable's noise temperature, that the cable is homogeneous and has a linear temperature profile, commands a further inspection. This letter analyzes these assumptions and clarifies the situations in which they hold. To substantiate this Kelvin-level discretion, a LNA is designed and measured.
KW - Noise temperature measurement
UR - http://www.scopus.com/inward/record.url?scp=15844393526&partnerID=8YFLogxK
U2 - 10.1109/LMWC.2004.842832
DO - 10.1109/LMWC.2004.842832
M3 - Article
AN - SCOPUS:15844393526
VL - 15
SP - 141
EP - 143
JO - IEEE Microwave and Wireless Components Letters
JF - IEEE Microwave and Wireless Components Letters
SN - 1531-1309
IS - 3
ER -