Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Variable Termination Unit for Noise-Parameter Measurements



Dazhen Gu, Dave K. Walker, James P. Randa


NIST has upgraded its measurement capability of noise parameters on low-noise amplifiers with a variable termination unit (VTU) in the 1 to 12.4 GHz frequency range. Such a unit allows improved time efficiency and accuracy in the noise-temperature measurements used to de-embed noise parameters of amplifiers. We present the design and the characterization of the VTU. Measured results of one particular amplifier at integer frequencies from 8 GHz to 12 GHz show satisfactory accuracy. The VTU method is also validated through comparison with results from the manual method.
IEEE Transactions on Instrumentation and Measurement


Amplifier noise parameters, source pull technique, noise measurement, uncertainty analysis.


Gu, D. , Walker, D. and Randa, J. (2009), Variable Termination Unit for Noise-Parameter Measurements, IEEE Transactions on Instrumentation and Measurement, [online], (Accessed July 18, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created April 1, 2009, Updated February 19, 2017