Extraction of Passive Device Model Parameters Using Genetic Algorithms

The extraction of model parameters for embedded passive components is crucial for designing and characterizing the performance of multichip module (MCM) substrates. In this paper, a method for optimizing the extraction of these parameters using genetic algorithms is presented. The results of this method are compared with optimization using the Levenberg‐Marquardt (LM) algorithm used in the HSPICE circuit modeling tool. A set of integrated resistor structures are fabricated, and their scattering parameters are measured for a range of frequencies from 45 MHz to 5 GHz. Optimal equivalent circuit models for these structures are derived from the s‐parameter measurements using each algorithm. Predicted s‐parameters for the optimized equivalent circuit are then obtained from HSPICE. The difference between the measured and predicted s‐parameters in the frequency range of interest is used as a measure of the accuracy of the two optimization algorithms. It is determined that the LM method is extremely dependent upon the initial starting point of the parameter search and is thus prone to become trapped in local minima. This drawback is alleviated and the accuracy of the parameter values obtained is improved using genetic algorithms.     

Parameter extraction and electrical characterization of highdensity connector using time domain measurements

Two coupled connector pins can be represented by an equivalent circuit consisting of six parameters, namely, self capacitance/self inductance per pin, mutual capacitance between pins and mutual inductance between pins. A systematic parameter extraction algorithm has been discussed in this paper using time domain reflectometry (TDR) measurements. This method uses a combination of stand-alone, common mode, and differential mode measurements to extract the connector parasitics. The accuracy of the equivalent circuit has been studied in detail using crosstalk measurements     

A Hybrid Method for Electromagnetic Propagated Resistivity Logging Data Inversion

Using an inverse technique for the array electromagnetic propagated resistivity logging (EPRL) data, a fine interpretation can be obtained about the resistivity distribution of an invaded profile. Generally, the Gauss-Newton algorithm (GN) is an efficient technique for the inverse problems; however, as a gradient-type optimization method, its accuracy and convergence depend strongly on the initial value. Even though this problem can be avoided by using a differential evolutionary algorithm (DE) as a global search optimization, it is computationally less efficient. In this paper, a hybrid inversion method of differential evolution has been developed to remove the strong dependence of the accuracy and convergence on the initial value. In this new method, an additional operation, which is designed with GN, is performed only to the best individual with a delay in the evolution processes of DE. Hence, the GN operation is used for the improvement of the convergence speed without leading to any decrease of the robustness of DE. The hybrid method is then extended to apply the inversion of EPRL data. Our results demonstrate its speed, steadiness, and efficiency of this hybrid method     

一种基于Kriging模型和受限差分进化的电磁结构快速优化算法

进化算法在各类电磁结构优化设计中有着广泛的应用，但由于需要在参数空间中进行随机搜索并仿真试探，优化效率普遍较低.针对这一问题，提出受限差分进化（Differential Evolution，DE）算法与Kriging代理模型相结合的电磁结构快速优化算法.算法根据参考设计结果建立圆柱管道空间，通过参数变换将进化区域限制在管道内部.Kriging模型学习管道内样本及其仿真数据，代替电磁仿真快速预测进化产生下一代种群的响应.相比整个参数空间，该算法DE寻优和Kriging学习的区域被显著减小，优化效率得到提升.通过一个波导双孔定向耦合器的优化设计，表明该方法的求解质量和收敛速度优于现有算法.     

混合粒子群和差分进化的定位算法

针对传统无线传感器网络(wireless sensor network,WSN)中节点定位精度不高的问题,提出了一种混合粒子群(particle swarm optimization,PSO)和差分进化优化(differential evolution,DE)算法。首先在PSO中引入惯性权重的自适应更新策略,以兼顾开发和勘探能力,在种群经过PSO进化后,然后根据提前设定的阈值,将其分为适应度值较大的Su种群和适应度值较小的In种群,In中的粒子使用DE算法继续优化。HPSO-DE算法结合PSO算法和DE算法的优点,达到较好的性能。然后用标准测试函数来检测该算法的性能,验证结果表明所提出的HPSO-DE在寻优速度和收敛精度较PSO和DE而言都有了较大提高。接下来将HPSO-DE方法应用到WSN网络节点定位场景上,从实验测试结果可以看出,其精度相比PSO平均提高了0.5 m左右,在定位上具有更大的优势。     

基于改进差分进化算法的连续小波变换电路

提出一种基于改进差分进化算法和开关电流微分器的连续小波变换实现的新方法。引入混沌初始化种群、自适应变异和指数递增交叉概率因子,提高差分进化算法的收敛速度和精度,构造小波函数逼近模型,并利用改进差分进化算法,求得小波逼近函数及频域传递函数。采用开关电流微分器作为基本单元,设计冲激响应为小波逼近函数的开关电流滤波器组,通过调节小波滤波器的时间常数,获得多尺度小波函数,实现连续小波变换。实验结果表明该方法可行。     

一种新的HEMT小信号模型参数提取方法

介绍了一种高电子迁移率晶体管(HEMT)的小信号参数提取方法——综合多偏置点优化参数提取法。该文首先推导并提出了器件的模型、确定外部参数和内部参数，其次介绍了多偏置点优化算法。最后，以PHEMT器件为例进行鲁棒性和精确性测试，实验采用一系列随机起始值，结果表明，提取的参数值与经验值相差小于1％。     

基于改进差分进化算法的合成孔径圆阵优化

天线阵列设计是合成孔径辐射计的一项关键技术。圆阵可以实现零冗余基线分布,具有结构简单、 易于与平台共形等特点,是当前广泛关注和应用的合成孔径辐射计天线阵列形式之一。针对以u-v 覆盖均匀程度最 大化为目标的合成孔径圆阵优化问题,利用一个新的目标函数,提出了一种基于改进差分进化算法的优化方法. 新 的目标函数具有计算量小和u-v 覆盖均匀程度衡量精度高的优点,并且改进的算法可以保持种群规模。典型的数值 仿真结果给出了16 ~40 个天线单元的优化圆阵排列, 验证了本文方法的有效性。     

Equivalent radiation source of 3D package for electromagnetic characteristics analysis

An equivalent radiation source method is proposed to characterize electromagnetic emission and interference of complex three dimensional integrated circuits (IC) in this paper. The method utilizes amplitude-only near-field scanning data to reconstruct an equivalent magnetic dipole array, and the differential evolution optimization algorithm is proposed to extract the locations, orientation and moments of those dipoles. By importing the equivalent dipoles model into a 3D full-wave simulator together with the victim circuit model, the electromagnetic interference issues in mixed RF/digital systems can be well predicted. A commercial IC is used to validate the accuracy and efficiency of this proposed method. The coupled power at the victim antenna port calculated by the equivalent radiation source is compared with the measured data. Good consistency is obtained which confirms the validity and efficiency of the method.     

Design of Digital FIR Filters Using Differential Evolution Algorithm

The differential evolution (DE) algorithm is a new heuristic approach with three main advantages: it finds the true global minimum of a multimodal search space regardless of the initial parameter values, it has fast convergence, and it uses only a few control parameters. The DE algorithm, which has been proposed particularly for numeric optimization problems, is a population-based algorithm like the genetic algorithms and uses similar operators: crossover, mutation, and selection. In this work, the DE algorithm has been applied to the design of digital finite impulse response filters, and its performance has been compared to that of the genetic algorithm and least squares method.     

An automatic parameter extraction technique for advanced CMOS device modeling using genetic algorithm

We in this paper present an computational intelligence technique to extract semiconductor device model parameters. This solution methodology is based on a genetic algorithm (GA) with an exponential type weight function, renew operator, and adaptive sampling scheme. The proposed approach automatically extracts a set of complete parameters with respect to a specified compact model, such as a BSIM model for deep-submicron and nanoscale complementary metal-oxide-semiconductor (CMOS) devices. Compared with conventional artificial step-by-step fitting approaches, the proposed extraction methodology automatically tracks the shape variation of current-voltage (I-V) curves and examines the first derivative of I-V curves; therefore, highly accurate results can be obtained directly. Applying the renew operator will keep the evolutionary trend improving by removing the individuals without mainly features. The sampling strategy will speed up the evolution process and still maintain the extraction accuracy in a reasonable range. A developed prototype is successfully applied to extract model parameter of N- and P-metal-oxide-semiconductor field effect transistors (MOSFETs). This optimization method shows good physical accuracy and computational performance, and provides an alternative for optimal device modeling and circuit design in nanodevice era. Genetic algorithm based automatic model parameter extraction bridges the communities between circuit design and chip fabrication; in particular, it will significantly benefits design of system-on-a-chip.     

一种稀布矩形平面阵的多约束优化方法

针对矩形孔径平面稀布阵的多约束优化问题(包括阵元数、阵列孔径和最小阵元间距约束), 提出了一种基于矩阵映射的差分进化算法.该方法把差分进化算法的优化变量与阵元位置坐标按照特定的关系进行矩阵映射, 使含有多约束的阵元分布优化问题转换为仅含差分进化算法优化变量上、下限约束的优化问题, 从根本上避免了进化过程中的不可行解.通过抑制阵列峰值副瓣电平进行仿真实验, 结果显示了该算法的高效性和稳健性, 且能获得比现有方法更好的优化结果.     

垂直腔表面发射激光器的小信号等效电路模型的研究

结合分析法和优化法,在ADS软件中对垂直腔体表面发射激光器(VCSEL)的小信号模型进行模型参数的提取,给出了具体的计算公式、参数提取数值及不同偏置电流下模拟结果和测量结果之间的误差,可以清楚的看出,这种提取参数的方法是十分高效的,可以使模拟结果和测量结果之间的误差相对于用单一的分析法提取出来的误差更小.     

基于差分进化算法的多维传感器动态解耦方法

差分进化算法(differential evolution algorithm,DE)是近年来比较流行的进化算法,被广泛应用于复杂的优化问题中.但常规的差分进化算法存在停滞现象,容易使算法收敛停止,鉴于此本文提出一种改进的差分进化算法,防止了停滞现象也加快了收敛速率并使算法能收敛到全局最优.基于小生境差分进化算法,提出...     

Four-Port Network Parameters Extraction Method for Partially Depleted SOI with Body-Contact Structure

This work presents a model parameter extraction method based on four-port network for RF SOI MOSFET modeling. The gate, drain, source and body terminals are served as four separate ports. Four-port measurement simplifies the determination of small-signal equivalent circuit model elements such as parameters related to the body terminal which become clear in the equivalent circuit analysis. The extraction method of the RF SOI MOSFET extrinsic parasitic elements was also presented. The accuracy of the model extraction was verified by measurement and simulation from 100 MHz to 20 GHz.     

Stepping toward standard methods of small-signal parameterextraction for HBTs

An improved HBT small-signal parameter extraction procedure is presented in which all the equivalent circuit elements are extracted analytically without reference to numerical optimization. Approximations required for simplified formulae used in the extraction routine are revised, and it is shown that the present method has a wide range of applicability, which makes it appropriate for GaAs and InP-based single and double HBTs. Additionally, a new method is developed to extract the total delay time of HBTs at low frequencies, without the need to measure h₂₁ at very high frequencies and/or extrapolate it with -20 dB/dec roll-off. The existing methods of finding the forward transit time are also modified to improve the accuracy of this parameter and its components. The present technique of parameter extraction and delay time analysis is applied to an InGaP/GaAs DHBT and it is shown that: (1) variations of all the extracted parameters are physically justifiable; (2) the agreement between the measured and simulated S- and Z-parameters in the entire range of frequency is excellent; and (3) an optimization step following the analytical extraction procedure is not necessary. Therefore, we believe that the present technique can be used as a standard extraction routine applicable to various types of HBTs     

基于混合变异差分进化算法的均匀面阵稀疏优化

差分进化算法(DE)已被广泛应用于解决稀疏面阵优化问题,针对DE 算法早熟、全局搜索能力差、容易陷于局部最优的问题,提出一种混合变异差分进化算法,通过加入概率因子来平衡算法收敛速度与全局搜索能力,以阵列孔径、阵元数量以及阵元间距为约束条件,将算法中的实数编码转化为二进制编码,以方向图平面峰值旁瓣电平之和最低为目标函数,通过优化后得到的阵元分布,得到稀疏优化阵列的三维方向图。仿真结果表明:该方法在满足约束条件的同时,能够避免算法早熟得到较优的目标函数值,概率因子为算法提供了额外的自由度。     

光纤陀螺稳定平台控制系统的设计与实现

针对重力测量中海空重力仪需要时刻保持稳定的垂直指向的问题,设计了一种双环比例、积分、微分(PID)控制方法来控制平台水平,隔离外界扰动;针对力矩电机设计中存在死区的特性,提出了一种死区补偿函数,减小电机死区对控制精度的影响;针对双环PID参数难以整定的问题,设计了一种优化的差分进化（DE）算法,减小参数整定时的工作量。仿真和实测实验结果表明,基于双环PID控制和死区补偿的系统稳定性高,控制精度优于30″;改进DE算法的参数整定性能优于遗传(GA)算法和粒子群(PSO)算法,且计算量小。     

广义切比雪夫滤波器等效电路参数的提取

通过对等效电路的分析,对广义切比雪夫滤波器各归一化参数的物理意义做了明确的说明,并且,在指定传输零点位置和电路拓扑结构的情况下,采用优化方法,提出了一种灵活有效的提取广义切比雪夫滤波器等效电路参数的方法。最后,用MATLAB编程实现了等效电路参数的自动化提取。     

一种求解约束优化问题的自适应差分进化算法

自适应算子选择方式已被用于差分进化算法求解全局优化问题及多目标优化问题,然而在求解约束优化时难于为自适应算子选择方式找到一种方式来恰当分配信用。为此,本文提出了一种基于混合种群的自适应适应值方式来对约束优化问题中变异策略进行信用分配并采用概率匹配方法自适应选择差分变异策略,同时对算法变异缩放因子与交叉率进行自适应设置提高算法的成功率。实验结果表明算法在求解约束优化问题相比于CODEA／OED, ATMES,εBBO-dm,COMDE 以及εDE算法有较高的收敛精度及收敛速度,同时验证了自适应方式的有效性。该算法可用于预报、质量控制、会计过程等科学和工程应用领域。