Stable Unidirectional Two-way Radio Frequency Transfer over 185 km Outdoor Optical Cable Based on Dual-PLL

Abstract

We design a novel phase-locked loop and demonstrate stable unidirectional two-way radio frequency transfer over 185 km outdoor optical cable based on dual-PLL. The fractional frequency stability of the received signal approaches 1.18 × 10 − 14@1 s and 1.63 × 10 − 15@10000 s.