In order to do this accurately it is necessary to understand how a number of variables affect the overall measurement uncertainty. For measurements with a noise figure analyzer the measurement system contributors would typically include the noise figure 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, 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.

Online Materials
To run the Java™ Model you must have a world wide web browser that supports Java™. Netscape Navigator 3.0 supports Java™ for HP-UX, other flavors of UNIX™, Windows® 95, Windows® NT, Macintosh™ 680xx and Power Macintosh™. Microsoft Internet Explorer supports Java™ for Windows® 95, Windows® NT, and Macintosh™. Unfortunately, Java™ is not supported by any browser on Windows® 3.1 due to platform limitations. Since Java™ is a rapidly evolving technology, the quality of Java™ implementations vary across platforms.

Netscape Navigator 3.0
Microsoft Internet Explorer

The uncertainty calculator web page containing the uncertainty calculator Java™ applet and some user instructions. This has been tested on Microsoft Internet Explorer 4.0 and on Netscape Navigator as bundled with Netscape Communicator 4.6.