广义网络理论结合平面电路法优化功率分配元件

本文研究的一分为二功率分配元件是无耗偶对称互易网络。采用网络理论研究了元件的最佳工作点；提出了广义网络理论结合平面电路法优化了功率分配元件。文中还给出了计算实例，所得结果与实验结果比较吻合。     

耦合纵缝馈电的短路波导宽边纵缝阵的分析与设计

基于三层结构（馈电缝、耦合缝、辐射缝）平面缝隙阵天线设计的需要,用场分析法对由耦合纵缝馈电的两端短路波导宽边直线纵缝阵进行了分析和综合。该法考虑了所有的互耦、高次模及波导壁厚的影响,得到了耦合纵缝馈电的两端短路波民宽边纵缝直线阵在辐射缝偏心距相同和缝长相同时直线缝阵口径分布等幅同相的结论。利用所得结论并结合泰勒线阵综合法提出了适合于对文中系统进行综合的有效方法。     

氦—氖激光血管内照射治疗脑梗塞疗效观察与机制探讨

目的：探讨低能量He-Ne激光血管风照射治疗脑梗塞的疗效。方法：将144例脑梗塞患者附机分为实验组和对照组,各72例,实验组采用低能量He-Ne激光血管内照射治疗,同时结合药物治疗,对照组仅给予药物治疗。结果：实验组和对照组总有效率分别是91.67%和75％,两组疗效显著（P＜0.05）。结论：低能量He-Ne激光血管内照射治疗脑梗塞疗效显著,安全可靠,无付作用。     

New Syndrome Check Error Estimation and Its Concatenated Coding

A low-complexity and high performance SCEE (Syndrome Check Error Estimation) decoding method for convolutional codes and its concatenated SCEE/RS (Reed–Solomon) coding scheme are proposed. First, we describe the operation of the decoding steps in the proposed algorithm. Then deterministic values on the decoding operation are derived when some combination of predecoder-reencoder is used. Computer simulation results show that the computational complexity of the proposed SCEE decoder is significantly reduced compared to that of conventional Viterbi decoder without degradation of the P_e performance. Also, simulation results of BER performance of the concatenated SCEE/Hard Decision Viterbi (HD-Viterbi) and SCEE/RS (Reed–Solomon) codes are presented.     

Intermetallic growth of wire-bond at 175°C high temperature aging

Two types of samples were applied in this wire-bond evaluation work for an Al-pad diffusion process. One was finished product for the cross-section examination of wire-bond and the other was without compound encapsulant used for the plane view examination of wire-bond interface. These samples were aged at 175 C in air from 0 h to 1008 h. It is found that the normal product which was ready on board existed ∼1 μm Au₂Al and Au₅Al₂ phases. The Au₂Al phase was then transformed to Au₅Al₂ phase in a 4 ∼ 72 h aging period. The Au₄Al phase formed along with the Au₅Al₂ phase in 72 h to 240 h aging period showing some porosity within the reacted phases. The total phase thickness increased to ∼4μm after 240 h aging. The Au₄Al phase became the major phase after 336 aging h. The reacted phase layer thickness increased to ∼6 μm and reached the steady state. A titanium-rich thin layer was also induced within the reacted phase layer. Three ternary phases as AlAu₂Ti, AlAuTi, and Al₂Au₂Ti are found in this titanium-rich layer. In particular, Al₂Au₂Ti could be a new phase.     

Uniplanar one-dimensional photonic-bandgap structures andresonators

This paper presents uniplanar one-dimensional (1-D) periodical structures, so-called photonic-bandgap (PBG) structures, and defect high-Q resonators for coplanar waveguide, coplanar strip line, and slot line. Proposed uniplanar PBG structures consist of 1-D periodically etched slots along a transmission line or alternating characteristic impedance series with wide band-stop filter characteristics. A stop bandwidth obtained is 2.8 GHz with a stopband rejection of 36.5 dB. This PBG performance can be easily improved if the number of cells or the filling factor is modified in a parametric analysis. Using uniplanar 1-D PBG structures, we demonstrate new high-Q defect resonators with full-wave simulation and measured results. These structures based on defect cavity or Fabry-Perot resonators consist of a center resonant line with two sides of PBG reflectors. They achieve a loaded Q of 247.3 and unloaded Q of 299.1. The proposed circuits should have many applications in monolithic and hybrid microwave integrated circuits     

Sub-50 nm P-channel FinFET

High-performance PMOSFETs with sub-50-nm gate-length are reported. A self-aligned double-gate MOSFET structure (FinFET) is used to suppress the short-channel effects. This vertical double-gate SOI MOSFET features: 1) a transistor channel which is formed on the vertical surfaces of an ultrathin Si fin and controlled by gate electrodes formed on both sides of the fin; 2) two gates which are self-aligned to each other and to the source/drain (S/D) regions; 3) raised S/D regions; and 4) a short (50 nm) Si fin to maintain quasi-planar topology for ease of fabrication. The 45-nm gate-length p-channel FinFET showed an I_dsat of 820 μA/μm at V_ds=V_gs=1.2 V and T _ox=2.5 mm. Devices showed good performance down to a gate-length of 18 nm. Excellent short-channel behavior was observed. The fin thickness (corresponding to twice the body thickness) is found to be critical for suppressing the short-channel effects. Simulations indicate that the FinFET structure can work down to 10 nm gate length. Thus, the FinFET is a very promising structure for scaling CMOS beyond 50 nm     

A multimodule parallelable series-connected PWM voltage regulator

This paper presents the analysis and design of a single-phase voltage regulator (VR) and its multinodule parallel control. The VR employs the pulsewidth modulation three-arm rectifier-inverter topology. The inverter side adjusts the load voltage with the series regulating structure aiming to minimize converter capacity and attain higher efficiency. The rectifier side regenerates the load power and executes the active power filter function to achieve unity power factor. Based on such high-performance VR, a resistive droop method combined with the P-V droop and Q-δ shift scheme is then proposed to control the current sharing such that multiple VRs can be paralleled directly without any control interconnection. The proposed parallel control technique possesses the features of fast response, precise voltage regulation, equal fundamental and harmonic current sharing, tolerance for parameter mismatch, and so on. Two prototype 1 KVA VRs are implemented, and the effectiveness is demonstrated by some simulation and experimental results     

Noise characteristics of GaAs-AlGaAs heterojunction punch-throughphototransistors

Novel GaAs-AlGaAs heterojunction phototransistors with a δ-doped base have been fabricated. Very high gain and low output noise have been measured. The measured noise is composed of shot noise associated with collector quiescent bias current and amplified shot noise due to collector leak current for nonpassivated devices. The high gain and low intrinsic noise characteristics of these transistors make them very promising in weak light detection     

通信光纤偏振模色散的在线测试-干涉法及其应用

重点讨论了干涉法测试单模光纤偏振模色散 ( PMD)的原理、方法 ,并对长飞光纤光缆有限公司生产的 G.65 2、G.65 5单模光纤进行了在线测试 ,根据测试数据 ,分别计算出了这两种光纤 PMD的链路值 .结果表明 ,长飞光纤光缆有限公司生产的这两种光纤的 PMD值均在标准范围之内