Architecture for high-scalability multiple-node wideband fiber-optic radio frequency distribution

Area of Science:

• Electrical Engineering
• Optical Communications
• Signal Processing

Background:

• Distributed antenna systems require precise phase and time synchronization for coherent signal superposition.
• Scaling these systems often introduces significant power penalties and synchronization challenges.
• Existing methods struggle with simultaneous calibration and phase error correction in wideband RF signal distribution.

Purpose of the Study:

• To develop a multi-node phase-stabilized distribution scheme for wideband radio frequency (RF) signals.
• To enable quasi-lossless scaling of remote sites in distributed antenna systems.
• To facilitate simultaneous time-delay calibration and phase error correction for coherent aperture systems.

Main Methods:

• Utilized an optical switch for quasi-lossless network expansion.
• Implemented a co-located radio frequency (RF) switch for time-division multiplexing (TDM).
• Employed an active phase compensation scheme with a phase-locked loop (PLL) and optical time delay line (OTDL).

Main Results:

• Achieved quasi-lossless scaling of remote sites with minimal power penalty.
• Enabled simultaneous time-delay calibration and phase error correction on a single wavelength.
• Demonstrated excellent phase noise suppression and wideband characteristics through experimental validation.

Conclusions:

• The proposed scheme is highly attractive for large-scale distributed antenna arrays.
• The system effectively supports key functions required for distributed coherent aperture systems.
• The method provides a robust solution for phase synchronization and time delay calibration in wideband RF signal distribution.