高阶边带对高倍频光毫米波系统的影响
Influence of High-Order Sideband on High-Frequency Millimeter Wave System
黄馨菂 1卢嘉 1王杨 1刘剑飞 1曾祥烨1
作者信息
- 1. 河北工业大学电子信息工程学院,天津 300401;天津市电子材料与器材重点实验室,天津 300401
- 折叠
摘要
在传统的高倍频光毫米波系统中, 当边带间的抑制比较大时, 高阶边带的存在可直接忽略.当边带抑制比很小时, 高阶边带的功率较高, 将对光毫米波产生影响.为研究高阶边带对生成高倍频光毫米波的影响, 利用级联马赫-曾德尔调制器 (MZM) 的抑制偶数阶边带方式产生8倍频光毫米波.在实际的光毫米波产生系统中, 高阶边带经过调制后会生成冗余的低阶边带, 使得边带功率累加, 相位不相干, 从而造成系统无法解调.为此, 详细讨论了不同调制深度下调制器输出的高阶边带对系统的影响.通过对高阶边带的分析可知, 当射频信号满足最优的相位关系式时, 由第1个MZM输出±1, ±3, ±5, ±7阶平坦边带后, 无需光滤波器, 即可直接经过第2个MZM调制得到4阶边带的8倍频光毫米波.利用该方法, 不需要大幅度的射频信号就可得到纯净的8倍频毫米波.该方案结构简单, 频谱纯度高.
Abstract
In the conventional high-frequency millimeter wave system, the high-order sidebands can be directly ignored when the sideband suppression ratio is relatively large.However, for a small sideband suppression ratio, the big power of a high-order sideband obviously influences the generation of millimeter waves.The effects of high-order sidebands on the generated high-frequency millimeter waves are mainly demonstrated in this paper.In addition, an eightfold-frequency millimeter wave is obtained based on even-order sideband suppression by the cascaded MachZehnder modulators (MZMs).In an actual optical millimeter wave system, the redundant low-order sidebands usually occur after the modulation of high-order sidebands, which makes the power of low-order sidebands accumulated.However the phases are incoherent, and thus the system is unable to demodulate.Therefore, the influences of high-order sidebands outputted from the modulators with different modulation depths are discussed in detail.From the analysis of high-order sidebands, one can know that when the radio-frequency signals satisfy the optimal phase formula, the±1 st, ±3 rd, ±5 th, ±7 th order flat sidebands are generated by the first MZM, and the eightfold-frequency millimeter wave with a 4 th order sideband can thus be obtained through the second MZM without a filter.With this scheme, apure eightfold-frequency millimeter wave can be obtained without large radio-frequency signals.For this scheme, not only the design structure is simple, but also the spectral purity is high.
关键词
光通信/偶数阶边带抑制/马赫-曾德尔调制器/毫米波Key words
optical communications/even-order sideband suppression/Mach-Zehnder modulator/millimeter wave引用本文复制引用
基金项目
天津市自然科学基金(15JCYBJC17000)
河北省科技计划项目(17275404D)
出版年
2019
NETL
NSTL
维普
万方数据