星载宽带跨频段微波光子射频通道实现技术研究

目前基于微波技术的射频通道带宽与频率受限、多频率变频能力受限、通用性差,严重制约了高通量卫星的频谱覆盖范围和大带宽多路变频能力.针对这一问题,本文在对微波光子射频通道研究现状对比分析的基础上,提出基于并联型架构的宽带跨频段微波光子射频通道实现方法,开展了相应的仿真分析及实验验证.测试结果表明：该射频通道下变频输入频率可覆盖27 GHz～52 GHz,输出频率可覆盖17 GHz～24 GHz;上变频输入频率可覆盖25 GHz～27 GHz,输出频率可覆盖37 GHz～43 GHz,且该射频通道工作带宽优于2 GHz,带内平坦度优于3 d B,变频增益优于-10 d B,无杂散动态范围优于100 d B?Hz^2/3.     

光子辅助太赫兹通信技术研究进展

面对互联网时代呈指数增长的全球数据流量,超高速通信的发展需求日益迫切,太赫兹通信因拥有巨大的可用带宽资源,成为下一代超高速无线通信关键技术之一。太赫兹通信系统分为电子学与光子辅助两种类型,其中后者在通信速率、频率灵活调控、与光纤接入网无缝融合等方面具有独特优势。首先介绍了典型光子辅助太赫兹通信系统的基本原理,在此基本原理框架下,梳理了系统中信号生成与接收、多维复用以及概率整形等技术的研究进展,并探讨了该类通信系统需要进一步解决的问题。     

Bandwidth-reconfigurable single-passband microwave photonic filter based on stimulated Brillouin scattering

A bandwidth-reconfigurable filter is necessary to meet the need of growing communication capacity and signal coverage frequency range. The stimulated Brillouin scattering (SBS) gain spectrum as a filter passband is used to extract desired microwave signals. Due to the fact that the passband is formed by mapping the Brillouin gain spectrum, bandwidth reconfigurability can be implemented by changing Brillouin gain linewidth. In this paper, a scheme using a 5-lines optical comb acting as a Brillouin pump is experimentally demonstrated. The spectrum of the 5-lines optical comb is extended by a binary phase shift keying (BPSK) pulse modulated signal. Experiments have shown that the 3-dB and 20-dB bandwidths of the filter are 196 MHz and 257 MHz, respectively, and its 20-dB shape factor is 1.31. The passband ripple is ~3.5 dBm with stop-band rejection of 20 dBm under 15 dBm optical pump power.