Affiliation of Author(s):电子信息工程学院
Journal:IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
Key Words:Digital phase demodulation frequency discriminator microwave photonics phase noise measurement photonic delay line
Abstract:A simple and high-sensitivity frequency-discriminator-based phase noise measurement system using photonic time delay and digital phase demodulation is comprehensively investigated and experimentally demonstrated. By applying a low-loss optical fiber to provide a large amount of time delay, high phase noise measurement sensitivity and large operation bandwidth are guaranteed. Meanwhile, digital phase demodulation is employed to avoid sophisticated feedback control and complex calibration required in conventional frequency-discriminator-based phase noise measurement scheme, which not only eliminates the phase noise measurement error introduced by the feedback loop but also suppresses the influence of the amplitude noise in the signal under test. In addition, a solution for the in-phase and quadrature mismatch problem in the digital phase demodulation is proposed. An experiment is performed. Accurate phase noise measurement is achieved in a large bandwidth from 2 to 35 GHz. With a 2-km single-mode fiber serving as the delay line, phase noise measurement sensitivity as low as -134 dBc/Hz at 10 kHz is achieved at a RF frequency of 10 GHz. The phase noise sensitivity can be further improved by applying a longer fiber. The proposed system is simple, accurate, and stable, and can be applied for analysis of high-frequency and ultralow phase noise microwave signal sources.
ISSN No.:0018-9480
Translation or Not:no
Date of Publication:2018-09-01
Co-author:史经展,Shilong PAN
Correspondence Author:张方正,潘时龙,zfz
Date of Publication:2018-09-01