Author(s): Cao, XH (Cao, Xu Hua); Fan, XJ (Fan, Xiao Jie); Li, GY (Li, Guang Yi); Li, M (Li, Ming); Zhu, NH (Zhu, Ning Hua); Li, W (Li, Wei)

Source: IEEE PHOTONICS TECHNOLOGY LETTERS Volume: 34 Issue: 1 Pages: 19-22 DOI: 10.1109/LPT.2021.3132423 Published: JAN 1 2022

Abstract: We report a novel simple photonic approach for measuring the Doppler frequency shift (DFS) and the angle of arrival (AOA) of a microwave signal in a radar detection system. The echo signals combined with a reference signal are applied to a dual-polarization Mach-Zehnder modulator (DPol-MZM), and a low-frequency electrical signal is generated after beating between the two signals in a low-speed photodetector. The DFS without direction ambiguity can be calculated by the value of the low-frequency signal. A phase difference is introduced between two echo signals which are sent to two sub-MZMs of the DPol-MZM respectively. The AOA is determined by the peak power of the down-convert signals, and a simple calibration is used to remove the amplitude of the echo signals and the reference signal by switching the output polarization states of the system. Compared with previously reported works, the proposed method carries out a comprehensive and multifunction measurement system based on a filterless and simple structure. Experimental results demonstrate the DFS errors within +/- 0.5 Hz for a 15 GHz echo signal with a frequency offset of +/- 100 kHz, and AOA measurement errors are within +/- 1 degrees for a range of 16 degrees - 82 degrees

Accession Number: WOS:000733210900005

ISSN: 1041-1135

eISSN: 1941-0174

Full Text: https://ieeexplore.ieee.org/document/9634050