频扫天线慢波线的幅相误差对天线方向图影响的分析

从理论上分析计算了频扫阵列天线慢波线的幅相分布误差对天线方向图的影响 ,给出了几组误差分布条件下频扫天线扫描波束指向偏离和副瓣电平变坏的结果 ,与试验小阵的测试数据比较 ,两者吻合较好 ,这对频扫天线慢波线的工程设计具有重要的指导作用。本文的分析方法也同样可用于相扫、频相扫以及相控阵天线的工程设计     

频扫天线慢波线的幅相误差以天线方向图影响的分析

从理论上分析计算了频扫阵列天线慢波线的幅相分布误差对天线方向图的影响,给出了凡组误差分布条件下频扫天线扫描波束指向偏离和副瓣电平变坏的结果,与试验小际的测试数据比较,两者吻合较好,这对频扫天线慢波线的工程设计具有重要的指导作用。本文的分析方法也同样可用于相扫、频相扫以及相控阵天线的工程设计。     

低成本宽角相频扫阵列研究

大角度的两维相频扫阵列具有更广阔的空域覆盖能力。本文,通过对普通直波导的改进,设计了一种新型波导慢波线窄边缝隙线阵,大大增加了波导在固定频带内的频扫范围。该阵列在10%的带宽内,具有方位相扫±45°、俯仰频扫大于20°的扫描能力。通过理论仿真与实测结果可以验证,该低成本宽角相频扫阵列具备可实现性,具有很高的工程应用价值。改进后的波导缝隙阵为进一步提升雷达天线的空域覆盖能力奠定基础。     

频扫单脉冲天线技术研究

为了提高采用频扫天线的雷达系统在频扫维的测角能力,本文重点讨论了频扫单脉冲天线的实现技术,分析了三种不同实现方法,并以带状线形式、脊波导宽边缝隙形式和窄边波导缝隙形式为具体实现形式,设计了三种基于不同实现原理的频扫单脉冲天线实例,仿真及实测结果表明,三种实现方法都的有效性和正确性,可以应用于实际工程中.     

一种Ku波段混合馈电频扫天线阵设计

研制了一种俯仰向波束固定,方位向频扫的Ku波段频扫平面天线阵.采用双层微带结构获得带宽约18%的宽带微带贴片天线作为阵列单元.天线阵俯仰向采用微带功分器及该种天线单元组成线阵.方位向为实现波束较大范围的频扫能力, 并提高天线阵的工作效率采用波导慢波线缝隙与线阵微带线电磁耦合结构进行馈电.在采用HFSS软件完成仿真设计的基础上,加工并测试了一套12×40规模的天线阵,结果表明该天线阵在工作频段内驻波比优于1.5,波束扫描范围大于80, 副瓣电平优于-20 dB,除中心频点外,增益大于26.5 dB.     

小驻波、低损耗慢波线设计

介绍了频扫雷达天线中小驻波、低损耗慢波线设计的关键技术,着重描述了经过改型的小驻波、低损耗慢波线耦合单元、180°波导E面弯头的设计和性能,最后给出了研制出的两型慢波线与国内国外同型慢波线的性能比较。     

快速机扫对系统角度偏差影响分析

机扫雷达在波束扫描过程中,由于天线转动引入额外的系统角度偏差导致测角精度的下降,尤其在快速机扫时引入的系统角度偏差甚至超过测角标准差。文中基于常见的单脉冲测角,从机理上推导了机扫天线转速对系统角度偏差的影响,并提出了一种系统角度偏差补偿方法,计算机仿真结果验证了文中推导和系统角度偏差补偿方法的有效性。     

超宽带天线极化特性对相位干涉仪测角精度的影响

在超宽带相位干涉仪体制测角系统的使用过程中发现,该体制对天线极化特性敏感,严重影响测角精度,尤其在低频段表现明显.文章对一种超宽带Vivaldi天线的极化特性进行了建模,从理论上分析了天线极化特性对来波信号极化测量的影响,其导致相位干涉仪测角系统精度降低.最后,试验测试证明了天线交叉极化特性对相位干涉仪测角精度的负面影响,并提出一种通过修正接收天线极化特性提高测角精度的途径,试验结果表明其可以显著提高测角精度.     

随机误差对电扫阵列天线副瓣和方向性系数的影响

研究随机误差对电扫阵列天线（包括频扫和相扫天线）方向性和副瓣电平的影响，根据频扫阵列天线实际存在的随机误差给出了计算结果。     

900MHz移动通信抗同频干扰天线的研究

本文采用赋形波辐射方向综合的方法，研究了９００ＭＨＺ移动通信抗同频干扰天线，经分析，计算该天线在辐射角０°－９１°之间的辐射被抑制故有抗同频干扰的能力。并能提高天线的增益和效率。结果表明具有一定的实用价值。     

SRR and S-shape slot loaded triple band notched UWB antenna

This paper demonstrates the design of a triple band notched ultrawideband circular microstrip patch antenna loaded with Complementary Split RingResonator (CSRR) and S-shaped slot in microstrip feed line. Complementary Split Ring Resonator slot and S-shaped slot are used to produce band notched characteristics for WiMAX band (3.30–3.60 GHz) and WLAN band (5.10–5.80 GHz) respectively. The downlink frequency band (7.25–7.75 GHz) of X-band for satellite communication is notched using Symmetrical Split Ring Resonator Pair (SSRRP) as electromagnetic coupling element near microstrip feed line which produces band stop characteristics. Measured results of fabricated antenna prototype are compared with simulated results and found in correspondence. The VSWR and vector current plots show evidence of the significant suppression in the desired frequency bands.     

电力线载波芯片ST7536在数据通信系统中的应用

电力线载波通信是用电力线路作为通信媒介进行数据传输。本文介绍了在低压配电线上用电力线载波专用芯片ST7536实现数据的传输,给出了应用实例,并详细说明了硬件和软件的实现方法。     

平行耦合线滤波器

介绍了交错平行耦合带状线滤波器的设计方法及其过程，用此方法设计了7．5～18GHz的带通滤波器，使用Microwave Office软件对此滤波器进行了仿真，并对滤波器进行了安装测试。     

Anti-buckling S-shaped vertical microprobes with branch springs

We propose the S-shaped vertical probes with branch springs for the wafer-level testing of IC chips. The conventional S-shaped vertical probe requires a guide structure to prevent buckling due to the large overdrive actuation involved. However, the guide structure not only increases the cost of fabrication, but it also requires a troublesome assembly procedure. In this paper, we present the S-shaped vertical probe with branch springs on the left and right sides of the main spring to prevent buckling. This probe was designed using finite-element methods and fabricated using Ni-Co electroplating. The performances of the probe for the wafer-level testing of IC chips were measured with the probe test equipments. Compared to the identical conventional S-shaped probe, the proposed probe has the overdrive (60 μm) that is 1.2 times larger and the contact force (25 mN) that is 2.5 times larger. This new S-shaped vertical probe satisfies the design requirements for a vertical probe without the guide structure and has the potential for use as a cost-effective guide-free probe card for the wafer-level testing of IC chips.     

An Assessment of Testing-Effort Dependent Software Reliability Growth Models

Over the last several decades, many Software Reliability Growth Models (SRGM) have been developed to greatly facilitate engineers and managers in tracking and measuring the growth of reliability as software is being improved. However, some research work indicates that the delayed S-shaped model may not fit the software failure data well when the testing-effort spent on fault detection is not a constant. Thus, in this paper, we first review the logistic testing-effort function that can be used to describe the amount of testing-effort spent on software testing. We describe how to incorporate the logistic testing-effort function into both exponential-type, and S-shaped software reliability models. The proposed models are also discussed under both ideal, and imperfect debugging conditions. Results from applying the proposed models to two real data sets are discussed, and compared with other traditional SRGM to show that the proposed models can give better predictions, and that the logistic testing-effort function is suitable for incorporating directly into both exponential-type, and S-shaped software reliability models     

两种不同Y分支光波导的弯曲损耗研究

针对低损耗S型弯曲Y分支的分析与设计,分别用弯曲损耗理论和有限差分光束传输法分析了两种不同的S型弯曲Y分支的损耗特性,比较了不同的波导宽度、分支间距和分支张角对波导输出损耗特性的影响,得出了一组最优化的Y分支波导设计参数.     

Study of the DC biasing effect on insertion losses in high-frequency interconnections

The paper deals with an experimental investigation of the behavior of high-frequency Si/SiO₂/Al based interconnects when an extra DC bias voltage is applied, by means of which the conductor line changes the surface properties of the semiconductor substrate. By superposing a DC bias to the high-speed signal applied to the line, the insertion losses caused by the semiconductor substrate show a significant decrease over the observed frequency range. In order to study this effect a number of test samples containing several microstrip asymmetric transmission lines were prepared and measured. The obtained results suggest a way of controlling the performance and energy propagation of interconnects on semiconductor substrates. The observed effect can be successfully applied in high-speed blocks with tunable parameters.     

瞬时超宽谱脉冲串产生方式

通过对国内外瞬时多脉冲产生技术的调研,结合超宽谱脉冲的特点,开展脉冲分割方式产生超宽谱多脉冲、形成线串联方式产生超宽谱多脉冲、多脉冲合成方式产生超宽谱多脉冲的技术研究,确定利用形成线串联方式产生超宽谱多脉冲的技术路线;对充电时间和开关电容等对产生多脉冲的影响因素进行分析和实验研究,改进了四脉冲形成线充电方式,完成超宽谱四脉冲产生实验装置的设计,在负载上获得瞬时超宽谱多脉冲,脉冲数4个,脉冲宽度3.5 ns,输出脉冲之间的间隔小于10 ns。     

基于S形函数的变步长LMS算法

针对定步长LMS算法在收敛速度、时变跟踪能力和稳态失调噪声几个重要指标上不能兼顾的问题,引入人工神经网络中一种常用激励函数———S形函数,并将其应用于变步长LMS算法中。结合算法对收敛速度、精度及稳态失调噪声的要求,引入改变S形函数曲线曲率及收敛终值的2个参数：α和β。分析当α和β值固定时的情况,仿真结果表明定参数算法若其值选择不当会引起较大误差。按照步长值在时变阶段自适应增大,在稳态阶段步长很小的原则,构造了变参数α（n）和β（n）,仿真结果表明变参数算法兼顾多个参数,整体表现较好。