提出了一种基于改进的光载波抑制调制方式的光学生成高倍频可调谐毫米波的方案.该方案利用均匀光纤光栅型声光可调谐滤波器选取光载波抑制信号中的两个边带分量进行拍频, 实现高倍频且倍频因子可调的毫米波信号的生成.为避免色散所致的码元时移效应, 将基带数据信号仅调制到光载波抑制信号的一个边带分量上.仿真验证了倍频因子分别为2,6,10,14,18和22的毫米波信号的生成.另外, 对22倍频下的光载无线电系统的链路性能进行了仿真分析, 毫米波信号在调制2 Gbit/s的非归零码型数据信号经50 km的光纤传输后, 系统的眼图仍保持良好的睁开度, 链路的功率代价仅为0.4 dB.系统具有良好的传输性能, 可以满足通信系统的需求.

A tunable multi-frequency optical millimeter-wave signals generator scheme based on optical carrier-suppressed modulation was proposed theoretically. Millimeter-wave signals with tunable frequency multiplication factor can be obtained through the beating of two sideband components of the optical carrier-suppressed signal which are selected by the uniform fiber Bragg grating based on acousto-optic tunable filter. What′s more, in order to avoid the time shift of code effect caused by the chromatic dispersion of the fiber, the baseband data signals are modulated on only one sideband component of the optical carrier-suppressed signal. To investigate the scheme, some simulations have been done. It turns out that optical millimeter-wave signals with frequency multiplication factors of 2, 6, 10, 14, 18 and 22 will be generated. The transmission performance of the downlink of the radio-over-fiber system are also evaluated. Under the situation that the frequency multiplication factor is 22, when the optical millimeter-wave signals modulated with none-return-to-zero data signals of 2 Gbit/s, the eye diagrams are still wide open after transmitting through the fiber of 50km. Meanwhile, the power penalty is only 0.4 dB. The results show that the system with well transmitting performance can meet the requirements of communication.