title: A collapse of the cross-spectral function in phase noise metrology.
abstract: Cross-spectral analysis is a mathematical tool for extracting the power spectral density of a correlated signal from two time series in the presence of uncorrelated interfering signals. We demonstrate and explain a set of amplitude and phase conditions where the detection of the desired signal using cross-spectral analysis fails partially or entirely in the presence of a second uncorrelated signal. Not understanding when and how this effect occurs can lead to dramatic under-reporting of the desired signal. Theoretical, simulated and experimental demonstrations of this effect as well as mitigating methods are presented.
authors.affiliation: National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA.
authors.forename: C W
authors.initials: CW
authors.lastname: Nelson
authors.affiliation: National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA.
authors.forename: A
authors.initials: A
authors.lastname: Hati
authors.affiliation: National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Howe