This paper proposes a novel low distortion high linearity CMOS bootstrapped switch, and the proposed switch can alleviate the nonlinear distortion of the on-resistance by eliminating first order signal-dependent varia...This paper proposes a novel low distortion high linearity CMOS bootstrapped switch, and the proposed switch can alleviate the nonlinear distortion of the on-resistance by eliminating first order signal-dependent variation of the overdrive voltage. Based on a 0.18 mm standard CMOS process, the simulation results show that at 100 MHz sampling clock frequency and 49 MHz input signal with 2Vpp, the proposed switch in differential mode has a Spurious-Free Dynamic Range(SFDR) of 90.1 dB.展开更多
A correlation-based digital background calibration algorithm for pipelined Analog-to- Digital Converters (ADCs) is presented in this paper. The merit of the calibration algorithm is that the main errors information, w...A correlation-based digital background calibration algorithm for pipelined Analog-to- Digital Converters (ADCs) is presented in this paper. The merit of the calibration algorithm is that the main errors information, which include the capacitor mismatches and residue amplifier distortion, are extracted integrally. A modified 1st pipelined stage is adopted to solve the signal overflow caused by the Pseudo-random Noise (PN) sequences. Behavioral simulation results verify the effectiveness of the algorithm. It improves the Signal-to-Noise-plus-Distortion Ratio (SNDR) and Spurious-Free-Dynamic-Range (SFDR) of the pipelined ADC from 41.8 dB to 78.3 dB and 55.6 dB to 98.6 dB, respectively, which is comparable to the prior arts.展开更多
Star fruit(Averrhoa carambola)is an important fruit tree in tropical and subtropical Asia.The tree blooms several times and fruits accordingly within one year.Controlling the flowering time and understanding the physi...Star fruit(Averrhoa carambola)is an important fruit tree in tropical and subtropical Asia.The tree blooms several times and fruits accordingly within one year.Controlling the flowering time and understanding the physiological mechanism of the induction of floral buds in A.carambola are indispensable to the industry.In this study,A.carambola potted trees were subjected to drought stress in a growth chamber.To avoid excessive drought stress and leaf abscission,trees were watered every 7 d and were sprayed with water every 2 d.The flowering rate was recorded,and the carbohydrate contents of the leaves,phloem,and xylem tissues were determined during the treatment and after re-watering.The results showed that drought stress increased the flowering rate in both drooping and water shoots,increased the relative conductivity,decreased the relative water content(RWC)of leaves.The total soluble sugar,sucrose,fructose,and glucose in leaves of the drooping shoots were increased.The starch contents in the xylem of both drooping and water shoots were also increased by the treatment.The results indicated that drought stress enhances carbohydrate accumulation in A.carambola.This study provides a potential way by water control to induce flowering without chemical in A.carambola.展开更多
基金Supported by the National Natural Science Foundation of China(Grant No.61404043)Doctoral Program Foundation of Institutions of Higher Education of China(No.201201111-20008)Key Laboratory of Infrared Imaging Materials and Detectors,Shanghai Institute of Technical Physics,Chinese Academy of Sciences(No.IIMDKFJJ-13-06)
文摘This paper proposes a novel low distortion high linearity CMOS bootstrapped switch, and the proposed switch can alleviate the nonlinear distortion of the on-resistance by eliminating first order signal-dependent variation of the overdrive voltage. Based on a 0.18 mm standard CMOS process, the simulation results show that at 100 MHz sampling clock frequency and 49 MHz input signal with 2Vpp, the proposed switch in differential mode has a Spurious-Free Dynamic Range(SFDR) of 90.1 dB.
基金Supported by the Doctoral Program Foundation of Institutions of Higher Education of China (No.20120111120008)State Key Lab of ASIC & System(Fudan University) (No. 11KF001)Special Fund for Doctoral Program (Hefei University of Technology) (No.2011HGBZ0953)
文摘A correlation-based digital background calibration algorithm for pipelined Analog-to- Digital Converters (ADCs) is presented in this paper. The merit of the calibration algorithm is that the main errors information, which include the capacitor mismatches and residue amplifier distortion, are extracted integrally. A modified 1st pipelined stage is adopted to solve the signal overflow caused by the Pseudo-random Noise (PN) sequences. Behavioral simulation results verify the effectiveness of the algorithm. It improves the Signal-to-Noise-plus-Distortion Ratio (SNDR) and Spurious-Free-Dynamic-Range (SFDR) of the pipelined ADC from 41.8 dB to 78.3 dB and 55.6 dB to 98.6 dB, respectively, which is comparable to the prior arts.
基金funded by the National Natural Science Foundation (31572080)the Guangdong Agriculture Research System (2016LM1130)
文摘Star fruit(Averrhoa carambola)is an important fruit tree in tropical and subtropical Asia.The tree blooms several times and fruits accordingly within one year.Controlling the flowering time and understanding the physiological mechanism of the induction of floral buds in A.carambola are indispensable to the industry.In this study,A.carambola potted trees were subjected to drought stress in a growth chamber.To avoid excessive drought stress and leaf abscission,trees were watered every 7 d and were sprayed with water every 2 d.The flowering rate was recorded,and the carbohydrate contents of the leaves,phloem,and xylem tissues were determined during the treatment and after re-watering.The results showed that drought stress increased the flowering rate in both drooping and water shoots,increased the relative conductivity,decreased the relative water content(RWC)of leaves.The total soluble sugar,sucrose,fructose,and glucose in leaves of the drooping shoots were increased.The starch contents in the xylem of both drooping and water shoots were also increased by the treatment.The results indicated that drought stress enhances carbohydrate accumulation in A.carambola.This study provides a potential way by water control to induce flowering without chemical in A.carambola.
