Performance Evaluation at the Remote Site for RF Frequency Dissemination Over Fiber

Abstract

In the frequency dissemination system over fiber, users can obtain highly stable RF frequency signal from one frequency source. To ensure that the stability loss of the system meets the user's need, performance evaluation for RF frequency dissemination over fiber is necessary. Considering the numerous users over fiber links and the long dissemination distance, traditional transfer quality evaluation method is not very practical, because the cost of the loop-back configuration is relatively large. In this paper, we propose a method to directly evaluate the radio frequency transfer quality via fiber links at the remote site. At the local site, the radio frequency signal is amplitude-modulated on continuous-wave lasers with two wavelengths. After multiplexing, the frequency signal is disseminated to the remote site. At the remote site, RF signal is detected from the continuous-wave optical carrier and transfer performance can be evaluated by measuring the phase fluctuation difference between two different RF signals. The remote signal does not need to be sent back to the local site. It will greatly simplify the structure of the frequency dissemination link, like in an antenna array system.