Multi-access RF transfer with passive phase correction

A multi-access RF transfer method with passive phase correction is proposed and demonstrated to achieve phase-stable RF signal distribution. First, a predistorted signal is generated from the probe RF signal and transmitted round-trip through a fiber link. Then, the probe signal and the pre-distorted signal modulate the orthogonally polarized components of an optical carrier, respectively, at a dual-polarization Mach-Zehnder modulator. The modulated signals are transferred to the remote nodes. The phase jitter of the fiber link can be eliminated by mixing the probe and pre-distorted signal in the electrical domain at each node. A proof-of-concept experiment is performed. A 5-GHz RF signal is successfully transmitted to two nodes with distances of 10 km and 15 km to the central office. The residual phase jitters are less than 1.09 ps (about 0.03 rad) and 1.59 ps (about 0.05 rad).