一种基于并联DPMZM结构的无滤波器16倍频光生毫米波方案

A filter-less scheme for frequency 16-tupling millimeter-wave generation based on double parallel DPMZM

提出了一种新的基于并联的双平行马赫曾德尔调制器(Dual parallel Mach Zehnder modulator,DPMZM)结构的光生毫米波方案,该方案无需滤波器即可产生高质量的16倍频毫米波。通过适当调节DPMZM下臂上的马赫曾德尔调制器(Mach Zehnder modulator,MZM)的偏置电压,可以灵活控制光的零阶边带的幅度;通过调节DPMZM上臂上MZM的调制系数和直流偏压,可以抑制奇次谐波;然后通过适当调节两DPMZM之间的相移,可以得到仅有±8阶边带的光谐波,后经光电探测器(Photo detector,PD)拍频得到高质量的16倍频毫米波信号。对16倍频毫米波产生的原理进行了详细分析,并通过仿真对方案的可行性进行了验证,光载波抑制比(Optical sideband suppression ratio,OSSR)为30.3 dB,RF杂散抑制比(Radio frequency spurious sideband suppression ratio,RFSSR)为23.5 dB。

In this research,a new millimetre wave(mm-wave)generation scheme based on parallel dual parallel Mach Zehnder modulator(DPMZM)structure is proposed,generating high-quality frequency 16-tupling millimetre wave without a filter.By properly adjusting the bias voltage of the MZM on the lower arm of DPMZM,the amplitudes of zeroth-order optical sideband can be flexibly controlled.Meanwhile,odd harmonics can be suppressed by adjusting the amplitude of the RF signal,the modulation index and a bias voltage of the MZM on the upper arm of DPMZM.Then,by appropriately adjusting the phase shift between two DPMZMs,only eighth order optical sidebands are retained which can beat a frequency 16-tupled mm-wave at the photodetector(PD).Theoretical analysis is given out in detail,and simulations are carried out to verify the proposed scheme.Results show that optical sideband suppression ratio(OSSR)higher than 30.3 dB and radiofrequency spurious sideband suppression ratio(RFSSR)not less than 23.5 dB are achieved using this method.