Characterization of Photonic Integrated Circuit for Millimeter-Wave-Band Carrier Generation

A silicon photonics radio-frequency (RF) synthesizer operating in the millimeter (mm-) wave and sub-THz bands suitable for clock signal distribution in b5G/6G radio access networks is realized and experimentally characterized. The photonic integrated circuit (PIC) operates as a frequency multiplier for an input local oscillator (LO) microwave signal reference, and is specifically designed for maximizing the available optical power level at its output for improved performance of the generated mm-wave band signal. Preliminary measurements performed on two different replicas of the circuit confirms that low-loss dual-tone selection from an on-chip optical frequency comb source can be achieved through high-order multi-resonant photonic integrated filter for the synthesis of 100 GHz and 200 GHz carrier waves.