# Definition

In microwave circuits described by scattering parameters, it is advantageous to regard noise as noise waves [5]. The noise characteristics of an n-port is then defined completely by one outgoing noise wave at each port (see 2-port example in fig. 2.1) and the correlation between these noise sources. Therefore, mathematically, you can characterize a noisy n-port by its scattering matrix and its noise wave correlation matrix .

 (2.1)

Where is the time average of and is the conjugate complex of . Noise correlation matrices are hermitian matrices because the following equations hold.

 Im   Im (2.2)

 (2.3)

Where Im is the imaginary part of and is the magnitude of .

This document was generated by Stefan Jahn on 2007-12-30 using latex2html.