This paper presents a fully-differential CMOS dynamic comparator for use in high-speed pipelined ADCs with low stage resolution. Because the architecture is based on the coupled current sources and differential input ...This paper presents a fully-differential CMOS dynamic comparator for use in high-speed pipelined ADCs with low stage resolution. Because the architecture is based on the coupled current sources and differential input pairs, this comparator＇s threshold voltage can be adjusted to a desired level. Compared with traditional comparators, this one shows significant improvement in area,power,and speed. Fabricated in 0.35μm CMOS technology,it occupies only 30μm × 70μm. Simulation and measurement results indicate the comparator has a sampling frequency up to 1GHz with 2Vpp differential input signal range and only 181μW power consumption under a 3.3V supply. The speed/power ratio reaches up to 5524GS/J.展开更多
The establishment of crop yield estimating model based on microwave and optical satellite images can conduct the mutual verification of the accuracy of the reported crop yield and the precision of the estimating model...The establishment of crop yield estimating model based on microwave and optical satellite images can conduct the mutual verification of the accuracy of the reported crop yield and the precision of the estimating model. With Shou County and Huaiyuan County of Anhui Province as the experimental fields of winter wheat producing areas, the linear winter wheat yield estimating models were established by adopting backscattering coefficient and Normalized Difference Vegetation Index（NDVI） based on images from the synthetic aperture radar（SAR）—RDARSAT-2 and HJ satellite photographed in mid-April and early May, 2014, and then comparisons were conducted on the accuracy of the yield estimating models. The accuracies of the yield estimating models established using co-polarized（HH） and cross-polarized（HV） modes of SAR in Jiangou Town, Shou County were 68.37% and 74.01%, respectively, while the accuracies in Longkang Town, Huaiyuan County were 63.10%and 69.10%, respectively. Accuracies of yield estimating models established by HJ satellite data were 69.52% and 66.43% in Shou County and Huaiyuan County, respectively. Accuracies of winter yield estimating model based on HJ satellite data and that based on SAR were closed, and the yield difference of winter wheat in the lodging region was analyzed in detail. The model results laid the foundation and accumulated experience for the verification, parameters correction and promotion of the winter wheat yield estimating model.展开更多
文摘This paper presents a fully-differential CMOS dynamic comparator for use in high-speed pipelined ADCs with low stage resolution. Because the architecture is based on the coupled current sources and differential input pairs, this comparator＇s threshold voltage can be adjusted to a desired level. Compared with traditional comparators, this one shows significant improvement in area,power,and speed. Fabricated in 0.35μm CMOS technology,it occupies only 30μm × 70μm. Simulation and measurement results indicate the comparator has a sampling frequency up to 1GHz with 2Vpp differential input signal range and only 181μW power consumption under a 3.3V supply. The speed/power ratio reaches up to 5524GS/J.
基金Supported by the National Natural Science Foundation of China(41205126)the Discipline Construction and Macroscopic Agricultural Research Project of Anhui Academy of Agricultural Sciences(13A1424)+2 种基金the Fund for Youth Innovation of Anhui Academy of Agricultural Sciences(14B1460)the Innovative Research Team for Agricultural Disaster Risk Analysis in Anhui ProvinceAnhui Academy of Agricultural Sciences(14C1409)~~
文摘The establishment of crop yield estimating model based on microwave and optical satellite images can conduct the mutual verification of the accuracy of the reported crop yield and the precision of the estimating model. With Shou County and Huaiyuan County of Anhui Province as the experimental fields of winter wheat producing areas, the linear winter wheat yield estimating models were established by adopting backscattering coefficient and Normalized Difference Vegetation Index（NDVI） based on images from the synthetic aperture radar（SAR）—RDARSAT-2 and HJ satellite photographed in mid-April and early May, 2014, and then comparisons were conducted on the accuracy of the yield estimating models. The accuracies of the yield estimating models established using co-polarized（HH） and cross-polarized（HV） modes of SAR in Jiangou Town, Shou County were 68.37% and 74.01%, respectively, while the accuracies in Longkang Town, Huaiyuan County were 63.10%and 69.10%, respectively. Accuracies of yield estimating models established by HJ satellite data were 69.52% and 66.43% in Shou County and Huaiyuan County, respectively. Accuracies of winter yield estimating model based on HJ satellite data and that based on SAR were closed, and the yield difference of winter wheat in the lodging region was analyzed in detail. The model results laid the foundation and accumulated experience for the verification, parameters correction and promotion of the winter wheat yield estimating model.
