提出了一个基于偏振调制的最佳接收灵敏度ROF链路系统。其根本原理在于实现具有最佳光载波边带比(OCSR)的光单边带调制技术,为此,利用偏振调制和滤波技术,线偏光首先经由一个特定偏振角α进入偏振调制器,然后一个固定起偏角β的起偏器...提出了一个基于偏振调制的最佳接收灵敏度ROF链路系统。其根本原理在于实现具有最佳光载波边带比(OCSR)的光单边带调制技术,为此,利用偏振调制和滤波技术,线偏光首先经由一个特定偏振角α进入偏振调制器,然后一个固定起偏角β的起偏器被用来合并偏振信息,最后利用一个光滤波器实现光双边带调制到光单边带调制的转换。研究发现所获得的OCSR只与两个偏振角(α和β)有关,通过仔细调节上述指标,可以将OCSR调谐至最佳值0 d B。利用仿真验证了上述结论,仿真发现通过将OCSR调谐至最佳值将大大提高ROF链路的接收灵敏度。展开更多
A broadband photonic analog-to-digital converter（ADC） for X-band radar applications is proposed and experimentally demonstrated. An X-band signal with arbitrary waveform and a bandwidth up to 2 GHz can be synchronou...A broadband photonic analog-to-digital converter（ADC） for X-band radar applications is proposed and experimentally demonstrated. An X-band signal with arbitrary waveform and a bandwidth up to 2 GHz can be synchronously sampled and processed due to the optical sampling structure. In the experiment, the chirp signal centered at 9 GHz with a bandwidth of 1.6 GHz is sampled and down-converted with a signal-to-noise ratio of 7.20 d B and an improved noise figure. Adopting the photonic ADC in the radar receiver and the above signal as the transmitted radar signal, an X-band inverse synthetic aperture radar system is set up, and the range and cross-range resolutions of 9.4 and 8.3 cm are obtained, respectively.展开更多
文摘提出了一个基于偏振调制的最佳接收灵敏度ROF链路系统。其根本原理在于实现具有最佳光载波边带比(OCSR)的光单边带调制技术,为此,利用偏振调制和滤波技术,线偏光首先经由一个特定偏振角α进入偏振调制器,然后一个固定起偏角β的起偏器被用来合并偏振信息,最后利用一个光滤波器实现光双边带调制到光单边带调制的转换。研究发现所获得的OCSR只与两个偏振角(α和β)有关,通过仔细调节上述指标,可以将OCSR调谐至最佳值0 d B。利用仿真验证了上述结论,仿真发现通过将OCSR调谐至最佳值将大大提高ROF链路的接收灵敏度。
基金supported in part by the National Natural Science Foundation of China(NSFC)(Nos.61690191,61690192,61420106003,and 61621064)Chuanxin Funding,and Beijing Natural Science Foundation(No.4172027)
文摘A broadband photonic analog-to-digital converter（ADC） for X-band radar applications is proposed and experimentally demonstrated. An X-band signal with arbitrary waveform and a bandwidth up to 2 GHz can be synchronously sampled and processed due to the optical sampling structure. In the experiment, the chirp signal centered at 9 GHz with a bandwidth of 1.6 GHz is sampled and down-converted with a signal-to-noise ratio of 7.20 d B and an improved noise figure. Adopting the photonic ADC in the radar receiver and the above signal as the transmitted radar signal, an X-band inverse synthetic aperture radar system is set up, and the range and cross-range resolutions of 9.4 and 8.3 cm are obtained, respectively.
