连续波雷达测距中的解模糊技术

研究连续波雷达测距中的距离模糊问题，分析几种常用解模糊方法的性能，并讨论参差比的选取对测距范围的影响。     

Scaling planar silicon devices

The generation-over-generation scaling of critical CMOS technology parameters is ultimately bound by nonscalable limitations, such as the thermal voltage and the elementary electronic charge. Sustained improvement in performance and density has required the introduction of new device structures and materials. Partially depleted SOI, a most recent MOSFET innovation, has extended VLSI performance while introducing unique idiosyncrasies. Fully depleted SOI is one logical extension of this device design direction. Gate dielectric tunneling, device self-heating, and single-event upsets present developers of these next-generation devices with new challenges. Strained silicon and high-permittivity gate dielectric are examples of new materials that will enable CMOS developers to continue to deliver device performance enhancements in the sub-100 nm regime.     

基于水印的图像认证和完整性保护技术

数字水印技术的发展为解决图像认证和完整性保护问题提供了新的思路。对用于篡改检测和图像认证的水印技术做了综述。数字水印技术根据其识别差错的能力分为四种类型:易损水印、半易损水印、混合水印和自嵌入水印。最后还对水印认证技术的安全性问题进行了讨论。     

Whispering-gallery-like modes in square resonators

The mode frequencies and field distributions of whispering-gallery (WG)-like modes of square resonators are obtained analytically, which agree very well with the numerical results calculated by the FDTD technique and Pade approximation method. In the analysis, a perfect electric wall for the transverse magnetic mode or perfect magnetic wall for the transverse electric mode is assumed at the diagonals of the square resonators, which not only provides the transverse mode confinement, but also requires the longitudinal mode number to be an even integer. The WG-like modes of square resonators are nondegenerate modes with high-quality factors, which make them suitable for fabricating single-mode low-threshold semiconductor microcavity lasers.     

Low-temperature poly-SiGe alloy growth of high gain/speed pin infrared photosensor with gold-induced lateral crystallization (Au-ILC)

The hydrogenated poly-silicon germanium (poly-SiGe:H) epitaxial film has been investigated using gold-induced lateral crystallization (Au-ILC) technology on a-SiGe:H layers at 10-h 350/spl deg/C annealing temperature and 60-sccm hydrogen (H/sub 2/) content. Using this optimal condition, the growth rate of the induced Au was as large as 15.9 /spl mu/m/h. With a low annealing temperature (/spl les/400/spl deg/C) and large growth rate, this novel technology will be noticeably useful for poly-SiGe:H pin IR-sensing fabrication on a conventional precoated indium tin oxide (ITO)-glass substrate. Under a 1-/spl mu/W IR-LED incident light (with peak wave length at 710 nm) and at a 5-V biased voltage, the poly-SiGe:H pin IR sensor developed by the Au-ILC technology, i.e., an Al (anode)/n poly-SiGe:H/i poly-SiGe:H/p poly-SiGe:H/ITO (cathode)/glass-substrate structure allowed for maximum optical gain and response speed. The optical gains and the response speeds were almost 600 and 130%, respectively, better than that of a traditional pin type. Meanwhile, the FWHM of a poly-SiGe:H pin sensor with Au-ILC technology was reduced from 280 to 150 nm. This reveals excellent IR-sensing selectivity. These IR-sensing trials demonstrated again that the proposed Au-ILC technology has very useful application in the field of low cost integrated circuits on optoelectronic applications.     

化学复合镀层激光处理研究

研究了激光处理对Ni-P -SiC化学复合镀层的影响。借助于扫描电镜、能谱仪、X射线衍射、显微硬度计等设备对激光处理后复合镀层的表面形貌、组织结构及性能进行了综合分析。结果表明 ,对复合镀层进行激光处理可以获得与炉内加热同样的镀层硬度 ,且当激光功率 4 0 0W ,扫描速度 1.5m /min时 ,镀层硬度高于炉内加热的硬度     

Near-ML multiuser detection with linear filters and reliability-based processing

The prohibitive - exponential in the number of users - computational complexity of the maximum-likelihood multiuser detector for direct-sequence code-division multiple-access communications has fueled an extensive research effort for the development of low-complexity multiuser detection alternatives. We show that we can efficiently and effectively approach the error rate performance of the optimum multiuser detector as follows. We utilize a multiuser zero-forcing or minimum mean-square error (MMSE) linear filter as a preprocessor and we establish that the output magnitudes, when properly scaled, provide a reliability measure for each user bit decision. Then, we prepare an ordered, reliability-based error search sequence of length linear in the number of users; it returns the most likely user bit vector among all visited options. Numerical and simulation studies for moderately loaded systems that permit exact implementation of the optimum detector indicate that the error rate performance of the optimum and the proposed detector are nearly indistinguishable over the whole predetection. signal-to-noise ratio range of practical interest. Similar studies for higher user loads (that prohibit comparisons with the optimum detector) demonstrate error rate performance gains of orders of magnitude in comparison with straight decorrelating or MMSE multiuser detection.     

Characteristics of low-leakage deep-trench diode for ESD protection design in 0.18-/spl mu/m SiGe BiCMOS process

This paper proposes a novel low-leakage BiCMOS deep-trench (DT) diode in a 0.18-/spl mu/m silicon germanium (SiGe) BiCMOS process. By means of the DT and an n/sup +/ buried layer in the SiGe BiCMOS process, a parasitic vertical p-n-p bipolar transistor with an open-base configuration is formed in the BiCMOS DT diode. Based on the two-dimensional (2-D) simulation and measured results, the BiCMOS DT diode indeed has the lowest substrate leakage current as compared to the conventional p/sup +//n-well diode even at high temperature conditions, which mainly results from the existence of the parasitic open-base bipolar transistor. Considering the applications of the diode string in electrostatic discharge (ESD) protection circuit designs, the BiCMOS DT diode string also provides a good ESD performance. Owing to the characteristics of the low leakage current and high ESD robustness, it is very convenient for circuit designers to use the BiCMOS DT diode string in their IC designs.     

单元串联式多电平高压变频器的起源、现状和展望

本文对单元串联式多电平高压变频器的起源和现状进行了总结,同时从无速度传感器矢量控制、大容量化、冗余设计等方面对该技术未来的发展趋势进行了展望。     

应用激光活化饵料藻种的研究

应用Nd:YAG激光(波长1.06μm,功率5w,照射时间0.5-3 min)和Ar+激光(波长488nm,功率70mw,照射时间5-15min)对长期保存的不同保存形式的塔胞藻(Pyramidomonassp.)进行辐照处理。研究了不同剂量激光辐照对藻体生长和叶绿素含量的影响。实验结果表明:照射剂量为60s的Nd:YAG激光及剂量为15min的Ar+激光对液体保存形式的藻种有较明显的促长效果,接种后这两种激光处理组的比生长速率分别较对照提高达53.33%和28.89%,叶绿素含量分别增加73.33%和65.69%。两种激光对液体保存藻种的活化效果均好于固体保存种。