Use of a mm-Wave Band Packaged Silicon Photonics Clock Generator in Hybrid Fiber-Wireless Systems for 6G
The ever-increasing requirements of current B5G and upcoming 6G networks in terms of low latency, high signal integrity and multi-gigabit per second data rates translate into ultra-wideband wireless transmissions operating in the mm-wave and sub-THz ranges and featuring low phase noise. Microwave photonics solutions fulfill all these needs beside providing wide tunability and low-loss radiofrequency signal distribution over fiber optics or free-space optics links. In addition, CMOS-compatible silicon photonics integration allows system miniaturization. Here, an optoelectronic packaged silicon photonics frequency-tunable optical clock generator is successfully used in a W-band wireless transmission of complex modulated data signals up to 4Gb/s. The device is used to generate a 98 GHz optical clock converted, after photodetection, to the electrical domain, starting from a lower-frequency 19.6-GHz local oscillator. An improved architecture for extending the frequency range an improving the output power is also discussed.