Signal integrity and crosstalk analysis of the transmission lines on SOI substrate for high-speed up to 50 GHz

On-chip RF loss management is a critical issue for the packaging of the silicon photonics ICs (Si-PIC) determining signal integrity of both devices and systems. In this paper, we present optimal condition of on-chip transmission lines (TLs) for Si-PIC based on SOI wafer. Optimal on-chip 3dB-loss length is studied and crosstalk is analyzed for the multichannel TLs. The 3dB length is calculated to be 8~10 mm, and adjacent channel crosstalk becomes less than -20dB when the channel separation is larger than 2 times of the TL width.