理论提出了一种获得高倍频因子的毫米波产生方案并对产生毫米波的Ro F下行链路性能进行分析。方案中利用三角波替代正弦波来驱动双驱动马赫增德尔调制器。通过三角波扫频,可以产生更多的频率分量。均匀光纤布拉格光栅可以选择出所需的频率分量进行拍频产生毫米波信号。倍频因子的调谐可以通过调节两个均匀光纤布拉格光栅的中心波长来实现。方案可获得倍频因子分别为4,6,8,10,12 mm的波信号,并对各种倍频因子下的Ro F下行链路性能进行了分析。结果表明,在各种倍频因子下,经过10 km光纤的传输,解调后眼图均能保持一定的张开度,满足通信需求。该方案为未来的无线电通信系统提供了一定的支持。
A tunable optical millimeter-wave generation scheme was proposed theoretically which was capable of obtaining high multiplication factor(MF), and the performance of Radio over Fiber(Ro F)downlink was numerically analyzed. The scheme was based on a dual-driving Mach-Zehnder modulator(DD-MZM) which was driven by triangular wave instead of sine-wave. More harmonics can be generated by using triangular wave sweep. With the help of uniform fiber Bragg grating(UFBG), two of the harmonics can be selected to generate millimeter-wave signal of different MFs. The MF can be tunable by adjusting the Bragg wavelengths of two UFBGs respectively. Millimeter-wave signals with MFs of 4, 6, 8, 10 and 12 were achieved. The Ro F downlink transmission performance of all these MFs was evaluated. The eye diagram after 10 km transmission is still wide open under the conditions of all the MFs. The results demonstrate that such a scheme can offer realistic solution to support future wireless systems.