Reconfigurable microwave photonic system with cascaded double ring resonator for generating millimeter wave signals suitable for 5G applications

A cascaded double ring resonator based microwave photonic system for generating millimeter wave signals is designed and analyzed. Variations in coupling coefficients between ring cavity and bus waveguides of the microring resonator is one of the significant aspect of this analysis. In the proposed system, sixth order sidebands (corresponding to millimeter wave frequencies) are generated upon precise selection of coupling coefficients. The optimal values of coupling coefficients which result in highest power of 60 GHz frequency component are found to be t(3) = 0.7, t(4) = 0.2. The millimeter wave frequency components with highest power are generated in the RF spectra of the photodetector at the drop port of MRR 2. Variations in input RF frequencies (between 1 GHz and 20 GHz) results in generation of millimeter wave signals lying in the range of 30-60 GHz. The generated millimeter wave signals are suitable for 5G small cell applications.