Ultra-low phase noise synchronization of microwave sources with fiber-optic timing system

We describe two different schemes for residual phase noise measurement of a dual-link optical-microwave timing system. The lengths of the fiber links are 1.2 km and 3.5 km. The residual single-sideband (SSB) phase noise of 10.833 GHz local oscillators lays below −135 dBc at 10 kHz offset. The RMS jitter integrated from 1 Hz to 10 MHz does not exceed 3 fs.