A 60-GHz Radio-Over-Fiber Fronthaul Using Integrated Microwave Photonics Filters

To lower the cost and to improve the reliability of next generation fronthaul links, we propose and demonstrate an analog 60-GHz radio-over-fiber fronthaul link employing two wavelength-tunable integrated microwave photonics filters for the first time. An integrated notch filter is cascaded with an integrated bandpass filter to offer the optical filtering function, resulting in a dual-passband filter profile with frequency separation of 60.25 GHz. We prove that the integrated optical filters are able to provide acceptable system performance through both experiment and numerical simulation. 4QAM signal with a bit rate of 5 Gb/s is transmitted in a fiber-based fronthaul link achieving a receiver sensitivity of -5.8 dBm at the forward error correction limit with 7% overhead.