Dynamic range improvement strategy for Mach-Zehnder modulators in microwave/millimeter-wave ROF links

作者：Zhang, Guoqiang^*; Li, Shangyuan; Zheng, Xiaoping; Zhang, Hanyi; Zhou, Bingkun; Xiang, Peng

来源：Optics Express, 2012, 20(15): 17214-17219.

DOI：10.1364/OE.20.017214

• RADIO
• SYSTEM

Intermodulation distortions are generated by Mach-Zehnder modulators when they are driven by signals with certain bandwidth in microwave (MW) and millimeter-wave (MMW) radio-over-fiber (ROF) links. The optical spectral structure of the distorted optical signal is investigated. A strategy to improve the dynamic range of MW and MMW ROF links directly in the optical domain is proposed and experimentally demonstrated. Based on optical spectrum processing, the third-order intermodulation distortions (IMD3s) of the generated signals are suppressed. A 107.2dB center dot Hz(2/3) spurious-free dynamic range (SFDR) of the MW/MMW ROF link is obtained, which is improved more than 20dB. A 16QAM signal is transmitted in the system and the error vector magnitude (EVM) is measured with and without the proposed technique. The influence of the nonlinearity of modulators on EVM is almost completely eliminated.

• 出版日期2012-7-16
• 单位清华大学; 中国人民解放军陆军工程大学