Abstract
A photonic approach for both wideband Doppler frequency shift (DFS) measurement and direction ambiguity resolution is proposed and experimentally demonstrated. In the proposed approach, a light wave from a laser diode is split into two paths. In one path, the DFS information is converted into an optical sideband close to the optical carrier by using two cascaded electro-optic modulators, while in the other path, the optical carrier is up-shifted by a specific value (e.g., from several MHz to hundreds of MHz) using an optical-frequency shift module. Then the optical signals from the two paths are combined and detected by a low-speed photodetector (PD), generating a low-frequency electronic signal. Through a subtraction between the specific optical frequency shift and the measured frequency of the low-frequency signal, the value of DFS is estimated from the derived absolute value, and the direction ambiguity is resolved from the derived sign (i.e., + or −). In the proof-of-concept experiments, DFSs from to 90 kHz are successfully estimated for microwave signals at 10, 15, and 20 GHz, where the estimation errors are lower than . The estimation errors can be further reduced via the use of a more stable optical frequency shift module.
© 2015 Optical Society of America
Full Article | PDF ArticleMore Like This
Xiaoyan Li, Aijun Wen, Wei Chen, Yongsheng Gao, Shuiying Xiang, Huixing Zhang, and Xiaoming Ma
Appl. Opt. 56(8) 2084-2089 (2017)
Qiang Zhang, Sihan Chen, Yan Li, and Hui Yu
Opt. Express 31(9) 14509-14520 (2023)
Shangjian Zhang, Heng Wang, Xinhai Zou, Yali Zhang, Rongguo Lu, and Yong Liu
Opt. Lett. 40(12) 2854-2857 (2015)