Research On Photonic True-Time-Delay System Based On MOMES Optical Switch

True-Time-Delay (TTD) is the main technology for phased array antennas (PAAs) beamforming applications. The research for photonic TTD has attracted more and more attention recently. In this thesis, we compare several kinds of TTD technologies and two structures of TTD networks, then propose and demonstrate a photonic TTD system based on micro-optical-electro-mechanical-system (MOMES) optical switch. The system realizes a 7-Bit TTD by using an OMM 8×8 MOMES optical switch. Every antenna element in the system corresponds to a different optical carrier. Different time delays between adjacent channels are obtained due to the chromatic dispersion of fiber delay lines (FDLs). Because all of the optical carriers share with the same light paths, the time delay differences between adjacent channels are independent of external factors and the beampointing of antennas is accurate.Hardware and software design are done for the system. The hardware design includes the driver circuit for the MOMES optical switch and the control circuit of single-chip. Otherwise, the software design includes the control program for the optical switch and the PC human-machine interface. In the experiments, a two-element TTD unit is constructed, and the time delay responses of the TTD system are measured. The results show that the time delay differences vary linearly with the wavelength spacing between adjacent optical carriers and the lengths of FDLs, which agrees well with theoretical analysis. Also, they indicate that the system has good antijamming ability and delay accuracy, which meets the design requirements.