Design of Microwave Photonic Bandpass Filter Based on Cascaded Silicon Microring Resonators

ABSTRACT

       Recently microwave photonic filters (MPF) have a great interest due to their advantages which include low loss, wide bandwidth tunability, reconfigurability, and no electromagnetic interference. This thesis presents a comprehensive optical transmission analysis of reflective-type microring resonators (R-MRR) using coupled mode theory, and design guidelines for MPF through two cascaded R-MRR using COMSOL software (version 6.1) for a 1550 nm wavelength communication system. The design is implemented using a silicon-on-insulator (SOI) platform based MPF that exhibits wide bandwidth tunability and reconfigurability, which is achieved by adjusting the coupling coefficient in the two coupling regions. In this structure, we introduce a grating coupler (GC) reflector to the drop port of MRR. The analysis and simulation results were confirmed by utilizing a GC reflector and Mach-Zehender-Interferometer (MZI) in the MRR, reconfigurable intensity responses were accomplished. The results of the proposed MPF showed the bandwidth and center frequency are adjusted from 0.3 to 6 GHz and 13 to 54.8 GHz, respectively, with a high rejection ratio reaching 70 dB. A new compact, low cost, and small loss design strategy may enable new integrated MPF in recent optical communication methods.