A Flexible Multi-Format Signal Generation Method Based on Optically Coupled Selector Switch

An approach for microwave signal generation with adjustable formats including ASK, PSK, FSK and FPSK (FSK-PSK) is proposed and demonstrated in this paper. In the proposed scheme, a phase modulator (PM) and an optical coupler form optically coupled selector switch (OCSS), which transmit the optical signal on specified path by adjusting its driving signal. Two parallel-placed Dual-Drive Mach-Zehnder modulators (DD-MZM) and a followed photodetector (PD) are employed to generate the multi-format microwave signals. From a theoretical analysis, the microwave signals with tunable formats can be obtained by properly adjusting the amplitude of the coding signals. The simulation and experimental results show that the ASK, PSK, FSK and FPSK signals are successfully generated, and the modulation format can be switched simply by adjusting the system parameters. In addition, the frequency and bit rate of generated signal can be adjusted according to the demand, so flexible tunability can be realized easily.