Simulation study on the high-quality 32-tupling millimeter-wave signal generation based on a filter-free photonic scheme with four DP-MZMs

In this work, a filter-free scheme of photonic generation of a high-quality 32-tupling millimeter-wave signal based on four dual-port MZMs (DP-MZMs) is proposed and simulated. In this scheme, four DP-MZMs are recombined into the two parallel DP-MZMs and the two cascaded DP-MZMs, respectively. After being modulated by a local oscillation signal, the light from the two parallel DP-MZMs is converted by a photodetector into an electrical signal, which is imposed on the electrodes of the two cascaded DP-MZMs. The simulation results show that the performances of the photonic microwave signal are affected by the modulation index, extinction ratio, and bias voltage of the DP-MZMs. Under the optimized operation parameters, a high-quality 32-tupling millimeter-wave signal with 46 dB radio frequency sideband suppression ratio (RFSSR) and 40 dB optical sideband suppression ratio (OSSR) is generated without using the filter. Because the two cascaded DP-MZMs are modulated by a small signal and there is no filter in the system, the high stability and high utilization rate of the sideband can also be realized in this scheme.