Design of 60GHz RF Transceiver in CMOS:Challenges and Recent Advances

With more than 40 years Moore scaling, the speed of CMOS transistors is around 100 GHz. Such fact makes it possible to realize mm-wave circuits in CMOS. However, with the target of achieving broadband and power-efficient operation, 60 GHz CMOS RF transceiver faces severe challenges. After reviewing the technology issues, regarding the 60 GHz applications, this paper discusses design challenges both from the system and the building block levels, and also presents some simulated or measured circuits results.     

Fabrication of Pb1‐xSnxTe/PbTe heterojunctions by liquid phase epitaxy

Abstract

Pb_1‐x Sn _x Te epitaxial layers were successfully grown on PbTe substrates by liquid phase epitaxy (LPE) technique. The compositions and surface morphology of the epitaxial Pb_1‐x Sn _x Te layers were controlled in the LPE growth, and p‐Pb_1‐x Sn _x Te/n‐PbTe heterodiodes with a good junction‐perfection factor were made.     

Propagation characteristics of the ten-parameter family of partially coherent general anisotropic gaussian schellmodel (AGSM) beams passing through first-order optical system

Abstract

Based on the closed property of AGSM beams under the action of first-order optical systems, the explicit transformation and twist expressions for the principal axes of intensity distribution, transverse coherence distribution and the principal curvatures of phase front in the cross-spectral density function of AGSM beams are derived. For typical applications, for AGSM beams passing through free space, the twist and variation regularities of the principal axes and the principal curvatures are analysed in detail. The twist-free conditions are discussed and the twist influenced by the physical parameters of the incident beam analysed. It is shown from the analysis that the principal curvatures of phase front are not zero at the reference planes where any of the corresponding principal axes of the beam spot obtains its minimum, and the conditions where the principal curvatures are zero is discussed.     

Enhanced Mechanical Properties by Cyclic Compression in TiNb/Zr-Based Metallic Glassy Composite

A significant enhancement of yield strength and large plasticity was obtained in TiNb/Zr₅₅Cu₃₀Al₁₀Ni₅ composite by cyclic compression at the yield point. This phenomenon resulted from the cooperation of the metallic crystalline alloy TiNb and metallic glassy matrix Zr₅₅Cu₃₀Al₁₀Ni₅ in the composite. It was found that a large dislocation density of TiNb was produced during cyclic compression, which resulted in the increase of the strength. Meanwhile, the improvement of plasticity of the composite benefited from the propagation of excess shear bands in the glassy matrix, which were produced during the cyclic compression process. Hence, the collective effect of both resulted in the improved yield strength and large plasticity of the composite.     

环境γ辐射剂量率受降水影响规律研究

利用高气压电离室连续测量我国东部某地环境γ辐射剂量率,同时监测降水参数。研究发现:降水引起剂量率升高,最大升幅达38.1%,降水总量最大的夏季升幅最大;剂量率升幅大雨中雨小雨;降水强度越大,降水开始后剂量率升高越快,剂量率最大值出现点比降水强度最大值出现点晚约1h。同一降水强度条件下,剂量率升高幅度,冬季春季秋季夏季,降雪降雨。     

Influence of Substrate Temperature on Stress and Morphology Characteristics of Co Doped ZnO Films Prepared by Laser-Molecular Beam Epitaxy

Znl_xCoxO （x = 0.05） thin films are deposited on sapphire （0001） substrates by laser-molecular beam epitaxy technique at different substrate temperatures. The structural, stress and morphology evolution features are investigated by means of X-ray diffraction and atomic force microscopy. The surface parameters of roughness exponent α, root mean square （RMS） roughness w and autocorrelation length ~ are calculated and the surface parameters are preliminarily analyzed. The values of ~ vary from 0.7 to 0.9. The RMS roughness w is less than 2.2 nm, and it increases with increasing Ts from 300 to 400 °C, and then decreases when Ts is 500 °C. The autocorrelation length ~ decreases monotonously with the increase in Ts from 300 to 500 °C, which indicates that the increase in Ts restrains the spread of the surface fluctuations until Ts is higher than 400 °C.     

Information technology adoption and continuance: A longitudinal study of individuals’ behavioral intentions

Extant research on information technology (IT) adoption and continuance has not adequately modeled the times of adoption by individuals. This study argues that individuals adopt an innovation at different times and are likely to be influenced by different factors over time. The theoretical models are empirically validated using data gathered at three points in time through surveys of 132 users of a new innovation. The results indicate that the innovation attributes and individual characteristics influence individuals’ intentions to adopt the innovation during the early stage, and the innovation attributes and contextual factors impact the individuals’ intentions during the later stage.     

Microstructure and mechanical properties of friction stir welded oxide dispersion strengthened alloy

Effect of friction stir welding (FSW) on microstructure and mechanical properties of oxide dispersion strengthened alloy MA956 was investigated. Fine grained microstructure was developed in the processed region with slight particle coarsening. Tensile behavior of the processed material was compared with that of the as-received material at room temperature. Results indicated that significant grain refinement during FSW compensated for the reduced particle strengthening contribution and enhanced tensile strength by 145 MPa without loss in ductility. Further analysis indicated a good agreement between experimentally measured yield strength and the strength calculated by Pythagorean superimposition of strengthening contribution in FSWed material.     

Delphi通过ADO技术访问数据库方法研究

Delphi是一种功能强大的编程语言,可以编写任何类型的程序。在众多的软件中,在数据库方面,Delphi表现出色,可以开发多种数据库结构的客户服务器模式数据库应用程序。文中研究了数据库程序开发中的最基本的一步,即如何用ADO连接数据库的方法。通过实例演示,展示了这种方法的细节,具有可操作性和可重复性,可供其他程序员借鉴,提高开发效率。     

Symbolic Reasoning About Quantum Circuits in Coq

A quantum circuit is a computational unit that transforms an input quantum state to an output state.A natural way to reason about its behavior is to compute explicitly the unitary matrix implemented by it.However,when the number of qubits increases,the matrix dimension grows exponentially and the computation becomes intractable.In this paper,we propose a symbolic approach to reasoning about quantum circuits.It is based on a small set of laws involving some basic manipulations on vectors and matrices.This symbolic reasoning scales better than the explicit one and is well suited to be automated in Coq,as demonstrated with some typical examples.