Open AccessInstantaneous microwave frequency measurement using few-mode fiber-based microwave photonic filters
Author(s) -
Zhiyong Zhao,
Kun Zhu,
Linyue Lu,
Chao Lü
Publication year - 2020
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.410847
Subject(s) - photonics , microwave , optics , radio frequency , broadband , frequency offset , band pass filter , physics , materials science , telecommunications , computer science , channel (broadcasting) , orthogonal frequency division multiplexing
Instantaneous frequency measurement (IFM) of microwave signals using photonic methods provides a novel and efficient approach for fast and broadband radio frequency (RF) signal analysis. Here, we propose and experimentally demonstrate a photonic-assisted IFM method utilizing a few-mode fiber-based microwave photonic technique. By offset splicing the few-mode fiber (FMF) with a single mode fiber, both LP01 and LP11 modes can be excited, which is used to develop a microwave photonic filter (MPF). A detailed analysis of the FMF as the true time delay line is presented. An amplitude comparison function (ACF) that is the ratio of frequency response traces of an MPF pair is established, which is used to determine the unknown microwave frequency instantaneously. The proof-of-concept experiment demonstrates a frequency measurement range of 0.5 GHz to 17.5 GHz and a measurement accuracy of ±0.2 GHz in most of the frequency points. The proposed system has the merits of simplicity, cost-effectiveness, compactness and robustness.