采用级联相位调制器和强度调制器产生四倍频光载毫米波的光纤无线通信系统

Radio-Over-Fiber System with Frequency Quadruple Optical Millimeter-Wave Generation Utilizing Cascaded Phase Modulator Along with an Intensity Modulator

理论和实验研究了基于载波抑制原理采用级联的相位调制器和强度调制器产生四倍频光载毫米波的原理。基于此原理,在中心站利用10 GHz的本振射频信号,通过调节两个调制器的相位差和强度调制器的偏置电压产生40 GHz光载毫米波信号,2.5 Gb/s的基带数据信号直接调制在光载毫米波上,经过20 km标准单模光纤传输至基站。实验研究表明,下行链路信号通过20 km标准单模光纤传输后,传输功率代价小于0.8 dBm,基带信号眼图依然清晰张开,简化了系统配置,信源稳定可靠。

We theoretically and experimentally analyzed the principle of frequency quadruple optical millimeter-wave generation utilizing phase modulator along with an intensity modulator based on optical carrier suppression （OCS） scheme. In the experiment,40 GHz optical millimeter wave （mm-wave） is generated by adjusting the bias of intensity modulator and the phase between the two modulators which are driven by 10 GHz radio frequency signal. 2.5 Gb/s baseband data is modulated on 40 GHz optical mm-wave directly and transmitted to the base station over standard single-mode fiber （SMF-28）. The experimental results show that the power penalty of downlink data signals which are transmitted over 20 km SMF-28 is less than 0.8 dBm. The eye diagram of the baseband signal is still clear. This scheme simplifies the radio-over-fiber system and mm-wave signals are stable and reliable.