基于CFD/CSD耦合的超声速舵面动载荷计算

该文分析了超声速气动控制舵面在瞬态气动载荷作用下的位移及应力的时域变化.采用基于Volterra级数的气动弹性系统降阶模型快速获得了舵面的颤振边界.通过CFD/CSD耦合计算,确定了舵面在颤振速度下的瞬态气动载荷,并利用参数空间下的有限元四结点方法将每一时刻的气动载荷插值并施加到结构结点上,进行了瞬态响应分析,得到了舵...     

一种升余弦成形滤波器的设计

给出一种适用于PHS基带系统中高性能成形滤波器,对比两种实现方法在基带芯片中的性能,利用最少的非零比特位来表示符号数的编码技术即符号数Canonic Sign Digit表示(CSD),采用子结构共享技术改进数字滤波器结构,实现了二进制补码与CSD的转换和系统中升余弦Nyquist成形滤波器的ASIC设计,在SMIC 0.18μm工艺下进行了功能仿真、综合和后仿真。     

高性能升余弦滤波器设计

给出了一种适用于PHS基带系统中的高性能成形滤波器,对比两种实现方法在基带芯片中的性能,利用最少的非零比特位来表示符号数的编码技术即符号数（Canonic Sign Digit,CSD）。采用子结构共享技术改进数字滤波器结构,实现了2进制补码与CSD的转换和系统中升余弦Nyquist成形滤波器的ASIC设计,在TSMC 0．18μm工艺下进行了功能仿真、综合和后仿真。     

CSD在GSM-R手持终端的实现

介绍GSM-R手持终端实现CSD功能的方法.应用GSM模块MC55实现编组站调车指令500ms内端到端收发功能.     

Ferroelectric SrBi 2 Nb 2 O 9 Thin Films by Aqueous Chemical Solution Deposition

SrBi 2 Nb 2 O 9 (SBN) thin films on a Pt/Ti/SiO 2 /Si substrate were prepared by aqueous chemical solution deposition. The precursor solution was synthesized by means of an 'aqueous solution-gel method', starting with stable, inexpensive and easily available inorganic salts which are dissolved in an aqueous solution of chelating or coordinating ligands (acetates and citrates). Afterwards the synthesized precursor was spin-coated. However, problems arose as a consequence of insufficient 'wetting' of the substrate surface by the aqueous solution (poor film-substrate adhesion). Instead of improving surface adhesion by the addition of a surface-wetting reagent, a new strategy was developed: prior to spin-coating the platinum surface characteristics were modified using a UV/ozone technique. In this way the precursor solution was not chemically changed. Wetting/wettability was verified by means of contact angle measurements. A uniform, three-layer thin film with a total thickness of about 200 nm was obtained after thermal treatment, as could be verified using SEM and XRD.     

基于FPGA的高阶高速FIR滤波器设计与实现

提出了一种基于FPGA的高阶高速FIR滤波器的设计与实现方法。通过一个169阶的均方根升余弦滚降滤波器的设计,介绍了如何应用流水线技术来设计高阶高速FIR滤波器,并且对所设计的FIR滤波器性能、资源占用进行了分析。     

CAutoCSD – Evolutionary Search and Optimisation Enabled Computer Automated Control System Design

This paper attempts to set a unified scene for various linear time-invariant (LTI) control system design schemes, by transforming the existing concept of "computer-aided control system design" (CACSD) to novel "computer-automated control system design" (CAutoCSD). The first step towards this goal is to accommodate, under practical constraints, various design objectives that are desirable in both time and frequency domains. Such performance-prioritised unification is aimed at relieving practising engineers from having to select a particular control scheme and from sacrificing certain performance goals resulting from pre-commitment to such schemes. With recent progress in evolutionary computing based extra-numeric, multi-criterion search and optimisation techniques, such unification of LTI control schemes becomes feasible, analytical and practical, and the resultant designs can be creative. The techniques developed are applied to, and illustrated by, three design problems. The unified approach automatically provides an integrator for zero-steady state error in velocity control of a DC motor, and meets multiple objectives in the design of an LTI controller for a non-minimum phase plant and offers a high-performance LTI controller network for a non-linear chemical process.     

基于CSD方法滤波器的FPGA优化设计

在高速信号处理中，特别是在大时宽带宽积条件下，高速雷达信号的数字正交采样和脉冲压缩包含大量的乘加运算，运算量非常大，使用DSP芯片实现需多片处理完成，使系统的工作延迟大、成本高、功耗大、调试困难。文中采用CSD（Canonic Signed—Digital）算法的思想，实现数字正交采样和脉冲压缩滤波器算法优化，可显著降低运算量，使用可编程逻辑器件迅速快捷完成系统的硬件设计，并用Ahera公司的FPGA芯片进行了验证，最后给出了结果比较和分析。     

高速高精度CORDIC处理器的ASIC实现

针对数字信号处理领域复数运算的要求,实现了一种16位高速高精度复数运算的通用CORDIC处理器。电路采用半定制设计流程,在200M时钟频率下通过Nanosim后仿真表明,电路达到了高速高精度的设计要求。可广泛应用于雷达、信号处理、通信等涉及到复数运算的领域。