Photonics Generation of Background-Free Multi-band Phase-Coded Signals

A background-free multi-band phase-coded microwave signal generator is proposed and experimentally demonstrated based on cascaded Mach-Zehnder modulator (MZM) and a dual-polarization dual-parallel Mach-Zehnder modulator (Dpol-DPMZM). A polarization beam splitter and a balanced photodetector (BPD) is followed to eliminate the interference of the baseband modulation signal and the single frequency signal. A proof-of-concept experiment is carried out. Multi-band phase-coded signals with frequencies of 5.5 GHz, 11.5 GHz and 22.5 GHz are obtained. The system is expected to be applied in multi-band and multi-mission radar systems.