Noise waves and passive linear multiports

摘要

Noise waves are a powerful means for characterizing noise in microwave circuits. A simple derivation is given for the relation between a passive circuit's noise-wave correlation matrix and its scattering matrix. It is shown that this relation, referred to as Bosma's theorem, can be readily derived from the fundamental principle that a passive multiport in thermodynamic equilibrium with reflectionless terminations produces uncorrelated output waves.