Distributed coherent microwave photonic radar with a high-precision fiber-optic time and frequency network

Release time:2023-05-08  Hits:

• DOI number:10.1364/OE.405465
• Journal:OPTICS EXPRESS
• Abstract:In this paper, we present a distributed aperture coherent microwave photonic radar (DCMPR) system by means of a high-precision fiber-optic time-frequency synchronization network (OTFSN). The microwave photonic radar units distributed at different geographic locations are connected with the fiber network. Meanwhile, the time and frequency reference of the central controlling station are stably transferred over the fiber network to each radar unit, of which transmit and receive times are synchronized by the reference signal to cohere the multiple radar apertures. Experimentally, we demonstrate a two-unit DCMPR system with a 12-km OTFSN, where both radar units are operated in X-band and with a bandwidth of 4 GHz. Through the OTFSN, the time difference of the transmitted waveforms at the two radar units can be maintained within about 26 ps. When full coherence on transmit and receive is achieved, the signal-to-noise ratio (SNR) can be increased by about 8.1 dB and 7.9 dB respectively for two unit radars. Moreover, three radar reflectors are clearly imaged and probed by utilizing the mutually coherent operation, yet they are not be detectable by the single radar case. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
• First Author:wang, Haojie, Li, Shangyuan, Xue, Xiaoxiao, Xiao, Xuedi, Zheng, Xiaoping
• Indexed by:J
• Document Type:Article
• Volume:28
• Issue:21
• Page Number:31241
• ISSN No.:1094-4087
• Translation or Not:no