研究了在采用光单边带(SSB)调制方式的光纤承载射频(ROF)系统中,射频(RF)信号对光载波的调制指数对调制产生的光载毫米波信号中光载波和光边带分量之间功率对比关系的影响。针对单边带光载毫米波信号中的光载波分量和光边带分量的功率相差较大时,ROF系统的接收灵敏度较低的问题,分析了决定光载波和光边带分量的功率的主要因素。并指出通过选择最佳的射频调制指数可以使光载波和光边带分量的功率平衡,给出了最佳调制指数的值。仿真结果证实了最佳射频调制指数能够使光载波和光边带分量的功率平衡,进而使微波光纤系统的光接收灵敏度达到最高。

The influence of the modulation index of the radio frequency (RF) signal on the optical carrier on the relation between power of the carrier component and that of the sideband component of the optical millimeter-wave signal generated by single sideband (SSB) modulation in the radio over fiber (ROF) system is theoretically and numerically investigated. In order to address the problem that when the carrier component is much larger than the sideband component in the optical SSB millimeter-wave signal that the receiver sensitivity of the radio over fiber (ROF) system is relatively low,the determinant of the power of carrier component and sideband component is analyzed. It is shown that an optimum RF modulation index can bring on a balance between the powers of these two components. It is verified by simulation results that the optimum RF modulation index can make the power of sideband equivalent to that of carrier component,thus results in the best receiver sensitivity of the radio over fiber system.