Open AccessPhase noise coherence of two continuous wave radio frequency signals of different frequency
Author(s) -
Rönnow Daniel,
Amin Shoaib,
Alizadeh Mahmoud,
Zenteno Efrain
Publication year - 2017
Publication title -
iet science, measurement and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.418
H-Index - 49
eISSN - 1751-8830
pISSN - 1751-8822
DOI - 10.1049/iet-smt.2016.0203
Subject(s) - uncorrelated , spurious relationship , phase noise , acoustics , frequency offset , coherence (philosophical gambling strategy) , phase (matter) , offset (computer science) , physics , multiplicative function , noise (video) , mathematics , optics , computer science , mathematical analysis , statistics , estimator , orthogonal frequency division multiplexing , programming language , quantum mechanics , artificial intelligence , image (mathematics)
A method is proposed for determining the correlated and uncorrelated parts of phase noise spectra (PNS) of two continuous wave radio signals of different frequencies, ω 1 and ω 2 . The PNS of the two signals and of mixed signals are measured. The PNS are modelled as having a correlated part that is the same for both signals, except for a multiplicative factor, and uncorrelated parts, that are different for the two signals. A property of the model that the PNS of some mixing products are linear combinations of the PNS of the signals at ω 1 , ω 2 , and ω 1 − ω 2 is experimentally verified. The difference of the PNS at ω 1 + ω 2 and ω 1 − ω 2 is proportional to the correlated part of the PNS and is a part of auxiliary functions that are used for finding the multiplicative factor and the correlated, partly correlated, and uncorrelated phase noise at different offset frequencies. A conventional spectrum analyser was used to characterise two signal generators, a phase‐coherent and a non‐phase‐coherent one. For the phase‐coherent generator the phase noise of two signals was found to be correlated for offset frequencies below 10 Hz, partly correlated for 10 Hz–1 kHz and uncorrelated above 1 kHz.