基于级联调制器的微波光子变频的优化技术  

Optimization Techniques for Photonic Microwave Conversion Based on Cascaded Modulators

作　　者：刘丽莉[1] 赵文红[2] 杨力 王巍[4] 

机构地区：[1]宣化科技职业学院航空铁道学院,河北宣化075100 [2]嘉兴学院南湖学院,浙江嘉兴314001 [3]西安电子科技大学网络与信息安全学院,西安710071: [4]中国电子科技集团公司第三十六研究所,浙江嘉兴314001

出　　处：《控制工程》2018年第1期160-164,共5页Control Engineering of China

基　　金：中国电子科技集团公司第三十六研究所通信信息控制和安全技术重点实验室基金课题

摘　　要：研究分析了基于级联调制器的微波光子变频系统，并对其进行性能优化。射频信号通过1个调制器调制光载波，该振信号通过第2个调制器进行再调制，然后进入光电探测器检测出混频后的信号。该级联结构能够实现射频和本振信号的位置分离，隔离度无限大。另外，通过采用低偏置技术和光滤波技术，可以分别提高系统的变频效率和动态范围。仿真结果显示，采用低偏置技术后，变频效率提高11．1dB；采用FBG对光载波抑制后，三阶交调失真得到显著抑制，三阶无杂散动态范围提高20．7dB。The photonic microwave conversion based on cascaded modulators is analyzed and its performance is optimized in this paper. The optical carrier is modulated by the RF signal through the first modulator and re-modulated by the LO signal through the second modulator. Then the modulated optical signal is sent to the photodiode for detection. The RF signal can be separated far away from the LO signal in this cascaded structure, leading to a high RF-LO isolation. In addition, the conversion efficiency and dynamic range of the system can be improved by low biasing and optical filtering techniques, respectively. Simulation results show that the conversion efficiency is improved by 11.1 dB, and the noise figure （NF） is reduced by 9.2 dB after optimization by the low biasing technique. After optimization by a fiber bragg grating （FBG）, the third-order intermodulation distortion （IMD3） is significantly suppressed, and the spurious-free dynamic range （SFDR） is improved by 20.7 dB.

关 键 词：微波光子变频 级联调制器 变频效率 噪声系数 无杂散动态范围 

分 类 号：TP18[自动化与计算机技术—控制理论与控制工程]