This paper presents a 3-stage differential cascode power amplifier (PA) for 109–137 GHz applications. At 120 GHz the circuit delivers 16.5 dBm saturated output power with 12.8 % power-added efficiency (PAE) without using power combining techniques. The chip was fabricated in 130 nm SiGe BiCMOS technology offering heterojunction bipolar transistors (HBT) with f T /f max of 300/500 GHz. The PA consists of three stages optimized accordingly to the design goals. The first stage operates in class A to provide high gain while the two following stages are biased in class AB and deep class AB in order to increase the efficiency. The circuit draws a maximum current of 100 mA from 3.3 V and 4 V supplies. It occupies only 0.24 mm 2 chip area excluding baluns and bondpads, which makes it attractive for future power combiners. The presented amplifier is suitable for radar applications, that require a high dynamic range.
This paper presents a highly power efficient amplifier. By stacking inverters and splitting the capacitor feedback network, the proposed amplifier achieves 6-time current reuse, thereby significantly boosting gm and lowering noise but without increasing power. A novel biasing scheme is devised to ensure robust operation under 1V supply. A prototype in 180nm CMOS has 5.5uV rms noise within 10kHz BW while consuming only 0.25uW, leading to a noise efficiency factor (NEF) of 1.07, which is the best among reported amplifiers.
Structures of the two-dimensional atomic nuclei on ZnO (0001)-Zn and (0001)-O polar surfaces were studied by first principles density functional theory. The polarity-dependent nucleation dynamics was investigated by simulating two-dimensional (2D) nuclei consisting of 1-8 ZnO monomers on both polar surfaces. According to total energy calculations, average binding energy per ZnO monomer of the surface nuclei was analyzed to investigate if the nucleation and growth will proceed reasonably in physics. We found nucleation on (0001)-Zn surface was easier than that on (0001)-O surface. By using atomistic thermodynamics analysis, we calculated the Gibbs free energy of formation of these nuclei and made a comparison between the two polar surfaces. On (0001)-Zn surface, the critical Gibbs free energy of formation is much lower than that on (0001)-O surface under the same supersaturation, which leads to a much larger ZnO growth rate and rougher morphology, in accordance with experimental results. In addition, energetic analysis of nucleation at real thermodynamic conditions was achieved by introducing the temperature-and pressure-dependent chemical potentials of ZnO precursors. (C) 2017 Elsevier B.V. All rights reserved.
Introduction: The prevalence of multimorbidity is increasing in developed countries, while corresponding research in Chinese population is limited.Methods: A population-based cohort in Yinzhou located in an eastern coastal area of China (961,008 adults >=18 years in 2009; latest mortality follow-up: Nov 2015; 22,637 deaths; 6.53 million person-years at risk) was assembled by linking epidemiological surveys, electronic records for chronic disease management, health administrative and medical records databases. Multimorbidity was defined as the presence of two or more following disorders: hypertension, diabetes, cardiovascular disease or cancer. History of selected diseases was extracted from the electronic records for chronic disease management. Follow-up on fatal events is achieved through records linkage to the regional system of death surveillance.Results: Overall age- and sex-standardized prevalence of one, two or >=3 disorders were 16.16% (16.09% - 16.23%), 4.11% (4.07% - 4.15%) and0.36% (0.35% - 0.38%) respectively, whereas 41.73%, 14.41% and 1.67% were observed in people aged 60 years and older. The all-cause mortality rate adjusted to the age of 60 was 4.77 per 1000 person-years. Comparing to people without any selected diseases, the age- and sexadjusted HRs for all-cause mortality were 1.17 (1.14, 1.21) in those with one disorder, 1.78 (1.72, 1.86) in those with two morbidities, and 2.97 (2.76, 3.19) in those with >=3 morbidities. The HRs in those with multimorbidites were higher in younger people and were heterogeneous among different combinations of multimorbidites. Population-attributable fractions (PAF) for all-cause mortality due to one, two or >=3 disorders were 2.63%, 3.04% and 0.67% respectively (1.28%, 7.69% and 2.34% in people aged 60 years and older).Conclusions: The CHERRY study can serve as a valuable big data resource for scientific research in China. Multimorbidity is becoming acommon condition in Chinese population, especially in older population, and is associated with high mortality. A complementary strategy is required for population health interventions.Author Disclosures: H. Lin: None. D. Zhang: None. P. Shen: None. Z. Xu: None. Y. Si: None. X. Tang: None. P. Gao: None.
