Due to the outstanding anti-interference capability against the ambient noise,LiDARs based on frequencymodulated continuous wave(FMCW)technology with high sensitivity and high signal-to-noise ratio(SNR)are essential t...Due to the outstanding anti-interference capability against the ambient noise,LiDARs based on frequencymodulated continuous wave(FMCW)technology with high sensitivity and high signal-to-noise ratio(SNR)are essential to achieve ideal photodetection of weak light.To significantly improve the weak light detection performance of balanced photodetectors,this work first demonstrates a novel near-infrared germanium-on-silicon(Ge/Si)avalanche photodetector with a three-electrode balanced scheme.The single three-electrode avalanche photodetector exhibits a high responsivity of>200 A=W near breakdown voltage.The three-electrode balanced avalanche photodetector(3ele-BAPD)achieves a common-mode rejection ratio(CMRR)of 50 dB at an operating wavelength of 1550 nm.We have set up the FMCW coherent detection system.The minimum detectable power of−93 dBm can be achieved,corresponding to an SNR of 3.2 dB and a detection probability of 54%.In comparison,the performance exceeds that of the two-electrode balanced avalanche photodetector(2ele-BAPD),which exhibits a minimum detectable power of−85 dBm with a corresponding SNR of 3.1 dB and a detection probability of 51%.The superior weak light detection performance enables the 3ele-BAPD to accomplish 3D imaging based on the FMCW LiDAR scheme.Moreover,the 3ele-BAPD is also applied to velocity measurement for 4D sensing.The applications of LiDAR velocity measurement and imaging are verified.展开更多
A new time-frequency transform, known as short-time Lv transform （STLVT）, is proposed by applying the inverse Lv distribution to process consecutive segments of long data sequence. Compared with other time-frequency...A new time-frequency transform, known as short-time Lv transform （STLVT）, is proposed by applying the inverse Lv distribution to process consecutive segments of long data sequence. Compared with other time-frequency representations, the STLVT is able to achieve better energy concentration in the time-frequency domain for signals containing multiple linear and/or non-linear frequency modulated components. The merits of the STLVT are demonstrated in terms of the effects of window length and overlap length between adjacent segments on signal energy concentration in the time-frequency domain, and the required computational complexity. An application on the spectrum sensing for cognitive ratio （CR） by using a joint use of the STLVT and Hough transform （HT） is proposed and simulated.展开更多
基金National Natural Science Foundation of China(62090054,61934003)National Key Research and Development Program of China(2022YFB2804504)+2 种基金Major Scientific and Technological Program of Jilin Province(20210301014GX)Jilin Provincial Development and Reform Commission Project(2020C056)Program for Jilin University Science and Technology Innovative Research Team(JLUSTIRT,2021TD-39).
文摘Due to the outstanding anti-interference capability against the ambient noise,LiDARs based on frequencymodulated continuous wave(FMCW)technology with high sensitivity and high signal-to-noise ratio(SNR)are essential to achieve ideal photodetection of weak light.To significantly improve the weak light detection performance of balanced photodetectors,this work first demonstrates a novel near-infrared germanium-on-silicon(Ge/Si)avalanche photodetector with a three-electrode balanced scheme.The single three-electrode avalanche photodetector exhibits a high responsivity of>200 A=W near breakdown voltage.The three-electrode balanced avalanche photodetector(3ele-BAPD)achieves a common-mode rejection ratio(CMRR)of 50 dB at an operating wavelength of 1550 nm.We have set up the FMCW coherent detection system.The minimum detectable power of−93 dBm can be achieved,corresponding to an SNR of 3.2 dB and a detection probability of 54%.In comparison,the performance exceeds that of the two-electrode balanced avalanche photodetector(2ele-BAPD),which exhibits a minimum detectable power of−85 dBm with a corresponding SNR of 3.1 dB and a detection probability of 51%.The superior weak light detection performance enables the 3ele-BAPD to accomplish 3D imaging based on the FMCW LiDAR scheme.Moreover,the 3ele-BAPD is also applied to velocity measurement for 4D sensing.The applications of LiDAR velocity measurement and imaging are verified.
基金supported by the National Natural Science Foundation of China(61571174)the Zhejiang Provincial Natural Science Foundation of China(LY15F010010)+3 种基金the Open Project of Zhejiang Key Laboratory for Signal Processing(ZJKL 4 SP–OP2013–02)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry[2013]693 and[2015]1098the Fundamental Research Funds for the Central Universities(ZYGX2014J097)the Technology Foundation for Selected Overseas Chinese Scholar
文摘A new time-frequency transform, known as short-time Lv transform （STLVT）, is proposed by applying the inverse Lv distribution to process consecutive segments of long data sequence. Compared with other time-frequency representations, the STLVT is able to achieve better energy concentration in the time-frequency domain for signals containing multiple linear and/or non-linear frequency modulated components. The merits of the STLVT are demonstrated in terms of the effects of window length and overlap length between adjacent segments on signal energy concentration in the time-frequency domain, and the required computational complexity. An application on the spectrum sensing for cognitive ratio （CR） by using a joint use of the STLVT and Hough transform （HT） is proposed and simulated.
