Low-Loss and Broadband Asymmetric Broadside-Coupled Balun for Mixer Design in 0.18-$mu{hbox {m}}$ CMOS Technology

This study presents an asymmetric broadside coupled balun with low-loss broadband characteristics for mixer designs. The correlation between balun impedance and a 3D multilayer CMOS structure are discussed and analyzed. Two asymmetric multilayer meander coupled lines are adopted to implement the baluns. Three balanced mixers that comprise three miniature asymmetric broadside coupled Marchand baluns are implemented to demonstrate the applicability to MOS technology. Both a single and dual balun occupy an area of only 0.06 mm². The balun achieves a measured bandwidth of over 120%, an insertion loss of better than 4.1 dB (3 dB for an ideal balun) at the center frequency, an amplitude imbalance of less than 1 dB, and a phase imbalance of less than 5deg from 10 to 60 GHz. The first demonstrated circuit is a Ku-band mixer, which is implemented with a miniaturized balun to reduce the chip area by 80%. This 17-GHz mixer yields a conversion loss of better than 6.8 dB with a chip size of 0.24 mm². The second circuit is a 15-60-GHz broadband single-balanced mixer, which achieves a conversion loss of better than 15 dB and occupies a chip area of 0.24 mm². A three-conductor miniaturized dual balun is then developed for use in the third mixer. This star mixer incorporates two miniature dual baluns to achieve a conversion loss of better than 15 dB from 27 to 54 GHz, and occupies a chip area of 0.34 mm².     

Optical and Electrical Characteristics of ZnO Films Grown on Nitridated Si (1 0 0) Substrate with GaN and ZnO Double Buffer Layers

The optical and electrical characteristics of zinc oxide (ZnO) films grown by molecular-beam epitaxy (MBE) on Si substrates were investigated. ZnO epitaxial layer was successfully grown on nitridated Si(100) substrate initially covered with high-temperature GaN and low-temperature ZnO double buffer layers using MBE. X-ray diffraction and photoluminescence results both indicated that a reasonable quality of ZnO epitaxial layer was obtained. As the CV measurement had indicated, the carrier concentration was reduced virtually in a linear fashion from ZnO surface down to GaN buffer layer. A reduction in electron concentration was caused by the carrier depletion due to the presence of the Schottky barrier of Ni/ZnO. The large density of electron accumulated at the ZnO/GaN interface was due to the large conduction band discontinuity and offset.     

Intelligent FinTech Data Mining by Advanced Deep Learning Approaches

Computational Economics - With the progress of financial technology (FinTech), real-time information from FinTech is huge and complicated. For various fields of research, identifying intrinsic...     

Low-Temperature Sintering and Microwave Dielectric Properties of Anorthite-Based Glass-Ceramics

TiO₂ nucleated anorthite-based glass-ceramics were fabricated from glass powders. After sintering and crystallization heat treatment, various physical properties, including apparent bulk density and water absorption, were examined to evaluate the sintering behavior of anorthite-based glass-ceramic. Results showed that the complete-densification temperature for specimens was as low as 900°C. Sufficient crystallization was achieved by subsequently raising the firing temperature to 950°C, and the dielectric quality factor was promoted to the maximum value. Contents of nucleating agent (TiO₂) played an important role in the dielectric constants. The crystallinity was controlled by raising the firing temperature at a constant heating rate. The degree of crystallization affected the dielectric properties of sintered glass-ceramics. At the resonant frequency of 10 GHz, anorthite glass-ceramics with 5 wt% TiO₂ possessed the lowest permittivity of 8 and exhibited appropriate dielectric properties as compared with those with B₂O₃ and 10 wt% TiO₂.     

Autointoxication mechanism ofOryza sativa

Ammonium sulfate and potassium nitrate added as a top dressing and rice straw were incorporated into soil to understand their effect on the chemical nature of the paddy soil and on the growth and yield of rice plants during two successive crop seasons. Redox potential (Eh) determination indicated that the paddy soil appeared to be the reduced form in mixture with rice residues. The amounts of ammonium nitrogen (NH₄ ⁺—N) and nitrate nitrogen (NO₃ ^–—N) were significantly higher in the second crop than in the first crop, and the quantity of NH₄ ⁺—N was about 10 times greater than that of NO₃ ^–—N. The incorporation of rice straw decreased both the available nitrogen and the soil cations, Zn²⁺, Cu²⁺, Ca²⁺, Mn²⁺, and Na⁺. The quantity of Zn²⁺, Cu²⁺, Mg²⁺, and Na⁺ was significantly lower in the second crop that that in the first. The growth and yield of rice plants were significantly affected by cultural treatment; thus the ammonium sulfate dressing treatment resulted in higher yields than the potassium nitrate treatment. The NH₄ ⁺—N treatment had an antagonistic effect on the phytotoxic nature of rice straw decomposed in soil. The phytotoxicity (primarily phenolic type compounds) of aqueous extracts of soil varied between treatments and was significantly higher in the soil which had been mixed with rice straw. This finding correlated well with the higher amounts of phytotoxic plant phenolics produced by the decomposing rice residues in the soil.This study was supported by the National Science Council of the Republic of China.Paper No. 215 of the Scientific Journal Series, Institute of Botany, Academia Sinica.     

Adaptive multilevel method for the air bearing problem in hard disk drives

An adaptive grid-generating algorithm is constructed and integrated with the multigrid method to form a numerical scheme that suits slider air-bearing simulation of hard disk drives. The relative truncation error, a by-product of the multigrid method, is used in grid adaptation criteria. Finer meshes are constructed over nodes of the current finest grid where the relative truncation error exceeds a predetermined tolerance. The union of these finer meshes forms a new level of grid, which may not cover the entire domain of the coarse grid underneath. The final grid system thus constructed is composed of levels of uniform grids with decreasing mesh sizes. This composite grid structure incorporates with numerical resolution as needed and efficiency of computation. A shaped rail, negative pressure slider is used to demonstrate the effectiveness of this numerical scheme. Compared with the traditional multigrid method, the proposed adaptive multilevel method can significantly reduce the computation work for achieving the same level of accuracy.     

Effect of montmorillonite clay addition on the morphological and physical properties of Jatropha curcas L. and Glycine max L. protein concentrate films

Protein concentrates from jatropha (JPC) and soy seeds (SPC) were obtained by solubilization and acid precipitation of proteins. JPC and SPC films were prepared by the casting method, using two different montmorillonite (MMT) clay concentrations and plasticized with glycerol. Film properties were evaluated by scanning electron microscopy, transmission electron microscopy, X‐ray diffraction (XRD), Fourier transform infrared spectroscopy, thermogravimetric analysis, tensile properties, water retention, and water vapor transmission rate (WVRT). Typical tactoid microcomposite structures were found to be heterogeneously dispersed in the films containing MMT. A small XRD peak was found in films with MMT. Slight improvements in thermal stability and tensile strength were observed in the films with MMT. Reductions in water retention and WVRT were obtained when MMT was added into the films. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44459.     

國道東部公路蘇澳花蓮段隧道规劃設計之探討

對計畫之隧道工程加以介紹外,並探討隧道通過困難地段之處理對策,兼對長隧道之通風系統及防災隧道之設計概念略作敘述,以期達成工程技術交流之日的。