Noise Figure Uncertainty Calculator

Rapid growth in satellite-communications and mobile-communications markets has contributed to the need for improved overall system performance which, in turn, provides pressure to improve the noise figure performance of subsystems and their components. Designers and manufacturers are therefore measuring lower noise figures than ever before.

In order to do this accurately, it is necessary to understand how a number of variables affect the overall measurement uncertainty. For measurements with an analyzer which measure noise figure the measurement system contributors would typically include the analyzer itself, the noise source, and the characteristics of the device under test (DUT). These factors interact in a complex way, but the overall measurement uncertainty can be modelled.

The purpose of our 'Noise Figure Uncertainty Calculator' is to provide the measurement uncertainty associated with a particular DUT based on its characteristics and the specifications of the measurement system. For the model to be accurate in the Y-factor measurement technique case, the DUT must have reasonable reverse isolation, so that mismatch on one port does not drastically affect the impedance seen at the other port. For a more complete analysis refer to the article "Calculate the Uncertainty of NF Measurements", written by Duncan Boyd, Microwaves & RF October 1999, pp.93-102.