提出了一种基于双平行马赫-曾德尔调制器(DPMZM)和受激布里渊散射(SBS)效应的10倍频mm波信号生成方案,具有覆盖频段高和频谱纯度高等优点。在本文方案中,低频率的射频(RF)信号通过DPMZM对激光器发出的光波进行调制,调节直流偏置电压,使DPMZM的主调制器和两个子调制器均工作在最小传输点(MITP),抑制光载波和偶数边带,进一步调节两个子调制器的调制深度和移相器的相移,抑制一阶和七阶边带,留下三阶和五阶边带,然后利用SBS效应进行布里渊边带滤波滤除三阶边带,仅保留五阶边带,再经光电探测器(PD)拍频即可获得10倍频mm波信号。通过仿真实验,以10GHz的RF信号为驱动信号,得到了100GHz的mm波信号,验证了方案的可行性。
A scheme based on dual-parallel Mach-Zehnder modulator (DPMZM) and stimulated Brillouin scattering (SBS) effect is proposed to generate millimeter wave signals with a frequency 10 times of the radio frequency (RF) signal, which possesses the advantages of wide frequency and high spectral purity. In this scheme, a low frequency RF signal modulates the lightwave by a dual-parallel Mach-Zehnder modulator in which the main modulator and two sub modulators are all biased at the minimum transmis- sion point via adjusting the dc bias to suppress the even-order sidebands. Then the first-order and sev- enth-order sidebands at the output of dual-parallel Mach-Zehnder modulator can be suppressed by prop- erly adjusting modulation indices of the sub modulators and phase shift of the phase shifter,so that the third-order and fifth-order sidebands can be retained. The third-order sidebands can be filtered out by SBS-assisted filter of stimulated Brillouin scattering effect,with fifth-order sidebands retained only. And then through beat frequency of the photoelectric detector (PD) ,millimeter wave signals with a frequency 10 times of RF signal can be obtained. Finally, simulation is performed to verify the feasibility of the scheme. When the frequency of the RF driving signal is 10 GHz, the millimeter wave signal with fre- quency of 100 GHz is achieved.