Multi-band QPSK signal transmission implemented with remote up-conversion and Schottky RF detectors in a 60-GHz millimeter wave radio-over-fiber system

A simple multi-band QPSK signal transmission scheme, constructed by using an optical remote up-conversion technique and a Schottky diode RF detector, is theoretically analyzed and experimentally implemented in a 60-GHz millimeter wave (mm-wave) radio over fiber (RoF) system, for the first time. There is no need for complex system architecture or any expensive high-frequency clock source in our scheme. Simulation results show that our scheme is highly tolerant to fiber dispersion, compared with the conventional 60 GHz multi-band RoF system. In the experimental demonstration, successful delivery of QPSK signals at two 60-GHz sub-bands is achieved over 50-km fiber and 4-m wireless distance.

► A multi-band RoF system is proposed with optical remote up-conversion.
► There is no need of any high-frequency clock source in our scheme.
► Our scheme is highly tolerant to fiber dispersion compared with conventional ones.
► Successful delivery of QPSK signals is achieved experimentally.