基于光子技术的实时频率测量方法

研究了一种基于光子技术的实时频率测量方法,该方法利用两个级联强度调制器构成光子混频结构.通过理论分析与模拟仿真,设计了光通道与射频通道延时差,以优化测量带宽,同时保证测量精度.由于测量系统对微波信号实现混频后,输出的直流光功率与频率存在对应关系,利用光功率计对直流光功率进行监测,便可实现实时频率测量.该系统未采用光电探测器,极大地降低了系统成本.实验结果表明,在1~6GHz频率下,测量误差低于±0.12GHz.

Real-time frequency measurement method based on photonic technique

A real-time frequency measurement method based on photonic technique is investigated. In this scheme, two cascaded intensity modulators are utilized to make up the structure of photonic mixing. By theoretical analysis and simulation, the time delay between optical path and radio-frequency (RF) path is designed in order to optimize the measurement range and ensure the measurement accuracy as well. After the microwave signal mixed in the measurement system, there is a relationship between direct current (DC) optical power and microwave frequency, so the real-time frequency measurement by using optical power meter to monitor the DC optical power can be realized. The scheme has not employed photodetector, and thus the system cost is reduced. The experimental results demonstrate that the measurement error is less than ±0.12 GHz in the frequency range of 1 to 6 GHz.