Analog radio-over-fiber links with a high SFDR for passive distributed antenna system applications using Lagrange...

Area of Science:

• Optoelectronics
• Radio-over-fiber communications
• Antenna systems

Background:

• Analog radio-over-fiber (ROF) systems are crucial for distributed antenna systems (DAS).
• Minimizing signal distortion, such as intermodulation and harmonic distortion, is essential for high-performance ROF-DAS.

Purpose of the Study:

• To propose a novel analog radio-over-fiber scheme for passive distributed antenna systems.
• To achieve a high spurious-free dynamic range (SFDR) by suppressing nonlinear distortions.

Main Methods:

• Development of a Lagrange multiplier constrained optimization model.
• Analysis of the trade-offs between RF output power, polarization incident angle, and RF power ratio.
• Simultaneous suppression of third-order intermodulation distortion and second-order harmonic distortion through polarization angle adjustment.

Main Results:

• The proposed scheme effectively suppresses key signal distortions.
• Optimization model successfully balances RF power, polarization, and power ratio.
• Simulated and experimental results validate the scheme's effectiveness and feasibility.

Conclusions:

• The developed analog ROF scheme offers a viable solution for passive DAS.
• The findings provide significant insights into nonlinear optimization for ROF systems.
• This work holds potential for future advancements in the design and manufacture of ROF-DAS.