Full-duplex radio-over-fiber system based on a novel octupling mm-wave generation scheme

A novel mm-wave generation scheme based on two phase modulators and two unbalanced Mach-Zehnder interferometers is proposed. Compared with the conventional Mach-Zehnder modulator-based scheme, the phase-modulator-based scheme can work steadily without an electrical control circuit for the DC bias, and it has smaller insertion loss. A full-duplex radio-over-fiber system was investigated by simulation, and its performance is not affected by chromatic dispersion for both downstream and upstream transmission. A 40-GHz mm-wave is generated from a 5-GHz driving signal. The system performance is analyzed by using eye diagrams and bit error rate. Results demonstrate that the performance is still very good, even after a 50-km transmission.