基于T-S模糊模型的非线性时滞系统H∞滤波器设计

基于Takagi-Sugeno模糊模型, 研究了时变时滞非线性模糊系统的滤波器设计方法. 通过构造改进的Lyapunov泛函, 结合自由权矩阵与矩阵解耦方法, 提出模糊H∞滤波器存在充分条件. 此充分条件较已有文献中类似条件具有更低的保守性. 并给出示例说明了所给出方法的有效性.     

可重构振荡器与双频滤波器的协同设计

实现了一种可重构振荡器与双频率滤波器的协同设计模块。振荡器通过开关二极管的通断来实现频率的可重构,工作频率分别为1.1 GHz和2.0 GHz。与双频滤波器协同设计后,振荡器在两个频率上频偏1 MHz的相位噪声分别从-109.1 dBc/Hz和-112.9 dBc/Hz改善为-125.6 dBc/Hz和-127.9 dBc/Hz,二次谐波抑制分别由协同设计之前的-25 dB和-10 dB改善为-44 dB和-55 dB。     

Extended Kalman and Particle Filtering for sensor fusion in motion control of mobile robots

Motion control of mobile robots and efficient trajectory tracking is usually based on prior estimation of the robots’ state vector. To this end Gaussian and nonparametric filters (state estimators from position measurements) have been developed. In this paper the Extended Kalman Filter which assumes Gaussian measurement noise is compared to the Particle Filter which does not make any assumption on the measurement noise distribution. As a case study the estimation of the state vector of a mobile robot is used, when measurements are available from both odometric and sonar sensors. It is shown that in this kind of sensor fusion problem the Particle Filter has better performance than the Extended Kalman Filter, at the cost of more demanding computations.     

一种改进的粒子滤波跟踪算法

传统粒子滤波跟踪算法的退化现象和巨大的计算量不利于其应用,尤其在实时性要求较高的视频监控场合。引入均值漂移算法进行粒子的采样调整,采用积分直方图加快每个粒子的直方图计算速度,以改进传统粒子滤波跟踪算法的速度和跟踪效果,满足实时跟踪需要。实验结果证明了改进算法的有效性。     

“数字信号处理”的MATLAB应用研究

针对“数字信号处理”课程教学过程中出现的由于概念抽象、公式繁杂引起的学生对知识点理解肤浅的问题,在讲解过程中采用了矩阵实验室（MATLAB）编程技术,将数字信号处理的基本理论和处理方法用图形化演示方式表示出来。给出的实例和教学实践表明,该方法能够增强学生的理解能力,牢固掌握数字信号处理的理论知识和分析设计方法,提高了教学质量。     

光纤陀螺在船载天线上的应用

光纤陀螺在船载天线的稳定控制中承担着十分重要的作用,根据光纤陀螺的零偏、标度因数（SF）、随机游走系数（RWC）等关键指标可以对光纤陀螺划分精度等级。在光纤陀螺的应用方面,讨论了设计方法,比如：供电设计、接口设计以及陀螺输出的数字滤波器设计和数字调试中的可视化设计,同时也对陀螺环的数字化实现、复合控制设计以及PID调试的常用技术以及隔离度的计算及分配方法进行了阐述。     

基于Linux的网络准入控制代理服务器的设计与实现

网络准入控制体系中,终端与策略服务器通过代理服务器连接。该文给出网络准入控制的实现流程,定义了代理服务器的功能。以Linux内核的网络模块为基础,提出一种两级过滤规则链的网络报文过滤方法,实现了准入控制代理的安全阻断功能。该文工作可作为网络准入控制代理服务器的实现参考与依据。     

Design and optimization of LNA topologies with image rejection filters

An important problem in designing RFIC in CMOS technology is the parasitic elements of passive and active devices that complicate design calculations. This article presents three LNA topologies including cascode, folded cascade, and differential cascode and then introduces image rejection filters for low‐side and high‐side injection. Then, a new method for design and optimization of the circuits based on a Pareto‐based multiobjective genetic algorithm is proposed. A set of optimum device values and dimensions that best match design specifications are obtained. The optimization method is layout aware, parasitic aware, and simulation based. Circuit simulations are carried out based on TSMC 0.18 μm CMOS technology by using Hspice. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010.     

A current‐mode tunable low‐supply‐voltage ring oscillator

A new circuit topology using a current‐mode low‐pass filter for sinusoids has been presented. The technique is relatively simple, in the proposed circuit, only three identical current‐mode low‐pass filters are connected to each other to realize the small signal path. No external passive components are required except for three capacitors. When compared with LC oscillators, the die area of this work, without inductors, is much smaller. When compared with voltage‐mode ring oscillators, the supply voltage of this work is much lower. As a particular example, a 2.4 GHz, 1.2‐V power supply, 5‐mW sinusoidal oscillator is demonstrated. The oscillation frequency is tuned by the value of that three capacitors, over ～900 MHz, and the tuning range is 37.5%. The phase noise results in ?94 and ?120 dBc/Hz at 1 and 10 MHz from the carrier, respectively. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010.     

A modified design approach for compact ultra‐wideband microstrip filters

A modified design approach for compact ultra‐wideband microstrip filters with cascaded/folded stepped‐impedance resonators is described. The key feature of the proposed method is to facilitate stronger coupling between stepped‐impedance resonators and, at the same time, eliminate the requirement of extremely small gaps in coupled‐line sections, as found in traditional designs. Simulations and measurements demonstrate that the filters designed with this technique exhibit good reflection, insertion‐loss, and group‐delay performance within the 3.1–10.6 GHz band. © 2009 Wiley Periodicals, Inc. Int J RF and Microwave CAE 2010.