Microwave Photonic Notch Filter And Phase Shifter Based On Fourier-Domain Optical Processor

Compared with the traditional microwave signal processing techniques, microwave photonic has advantages such as realizing high bandwidth, overcoming the inherent bottlenecks of electronic techniques, low loss and immunity to electromagnetic interference. Therefore, microwave photonics will own a bright application prospect in the future. In this thesis, we propose a novel Microwave Photonics Notch Filter(MPNF) and two novel photonic microwave phase shifters based on Fourier-domain optical processor(FD-OP), and it mainly consists the following contents:(1) Novel all-optical tunable flat-passband MPNF is proposed. The FD-OP is used to realize single sideband modulation by filtering out one phase modulated sideband. Then the FD-OP is programmed to control the amplitude and phase of the carrier and the remaining sideband. Experiment results demonstrate that this novel MPNF exhibited a flat passband with <1 dB ripples, a deep notch of <35 d B, and low group delay ripples of <±25 ps. The tunability, stability and repeatability of this scheme are also demonstrated.(2) We propose a broadband photonic microwave phase shifter based on the FD-OP. Detailed theoretical on the FD-OP based phase shifter and simulation results are provided. By controlling the amplitude and phase of the two RF modulation sidebands,we extend the FD-OP based phase shifter lower RF operating frequency to 7.5 GHz. This novel phase shifter can realize a phase shift range from-180°to +180°with < 3 dB amplitude variation and < 4° phase deviation over the 7.5 to 26.5 GHz frequency range. This novel phase shifter also has excellent stability with < 0.2 dB amplitude variation and < 2° phase variation over the period of almost 5 hours.(3) A high output power photonic microwave phase shifter is presented. It is based on dual sideband phase control technique. Experimental results demonstrate this high output power phase shift achieves 14 dB increase in the output RF signal power compared to a conventional singlesideband modulation based phase shifter over the frequency range from 11 to 26.5 GHz.