无源二端口网络的综合

本文论述了双端接阻容负载RC二端口网络转移电压函数的极点与RC阻抗和导纳乘积的零,极点位置分布关系定理.导出了双端接载与等效单端接载网络转移电压函数之间关系的数学模型,利用一次归并和两次分解途径给出了双端接任意阻容负载网络的实现方法.     

复合多端口网络的参数矩阵计算

一些电路教材对二端口网络的连接方式进行了介绍并给出复合二端口参数矩阵的计算方法。多个二端口的任意连接可以构成复合多端口网络,其参数矩阵也可以由构成它的二端口网络的参数矩阵表示。本文类比了电路网络中的关联矩阵,建立描述二端口和复合多端口关系的端口关联矩阵,并利用二端口的特性和串并联的特点,给出了求解复合多端口网络参数矩阵的新方法。     

用变载法计算二端口无源网络参数

给出了用变载法计算无源二端口电路参数的方法。该方法可以充分利用已有的算法。简化了计算二端口电路参数的计算方法。具有较高的实用性。     

利用高斯消去法求无源二端口网络参数

历来求无源二端口网络参数，用网络两个端口的开路或短路分别去求出二端口网络的各个参数。求解时对于简单的网络尚可，然而只要网络稍复杂，即难于求解。本文提出一种统一的方法用于求解网络的参数，利用变形后的高斯消去法，对网络解耦，从而求得两端口网络的参数，算法统一，既可用以计算机辅助计算，亦可用于手工计算，方便简捷，尤其是对于Ｙ参数和Ｚ参数。     

二端口RC网络的实现条件

本文提出了二端口RC网络单、双端侧接任意RC负载时转移函数可实现的充要条件,使RC网络综合理论得到完善。     

基于Multisim10的二端口参数的测量

从本文使用Muhisim10仿真软件测试二端口网络的Y参数和A参数来看,在教学上用Multisim10软件研究二端口网络是很方便的。使用它可以在任意变换网络的元件及其位置,变换激励电源,变换输入端与输出端情况下,研究网络参数及参数间的相互转换关系。还可以借助仿真双踪示波器研究放大电路等二端口网络参数的相位特征。使二端口...     

计算网络多端口多参数高阶灵敏度的简便方法

本文首次给出了函数矩阵Hadamard乘积的微分性质,在文献[1]的基础上,推得了网络多端口多参数二阶灵敏度的矩阵表达式。该文指出计算网络多端口多参数二阶灵敏度的简便方法,是通过一个所谓“基础子阵”的Hadamard乘积的简单运算来实现的,这个基本思想同样适用于更高阶情况。     

无源对称五端口网络散射参数幅值和相角的分析

本文讨论了无源五端口网络,给出了网络损耗对S参数的影响。得到的结论可用于对六端口网络分析仪的分析。且结论适用于任何频率下的网络。     

关于互易二端口网络互连的讨论

互易电路及二端口电路互连是电路课程教学中的重要内容。本文讨论了互易二端口电路互连后总二端口电路的互易性,给出了一般性结论及证明,即互易二端电路互连后如仍满足端口定义,则互连后的总二端电路仍然是互易的。对于对称二端电路,也有类似的结论。本文的讨论对电路课程的教学具有一定的参考价值。     

Transistor S parameter measurement: 2-port to 3-port transforms

In 2-port s parameter measurements on active devices, residual common-electrode impedance can cause serious errors, particularly in the common-emitter configuration. Transforms have already been given for the elimination of this impedance prior to transformation to the corresponding 3-port parameters for checking the sum-to-unity property. It is shown that, by combining the two sets of transforms, it is possible to convert directly from the measured 2-port parameters, including the effect of common-electrode impedance, to 3-port parameters. The necessary circuit conditions that must be satisfied in the use of the transforms are re-emphasised.     

Transistor S parameter measurement: corrections for 2-port common-electrode impedance and the corresponding 2-port to 3-port transforms

In 2-port transmission-parameter measurements on active devices, a residual common-electrode impedance can cause serious errors, particularly in the common-emitter configuration. Transforms are given which enable the true S parameters to be derived in terms of the measured parameters and the common-electrode impedance. It is shown that the inverses of these transforms can be used to derive the 3-port S parameters in terms of measured 2-port values. It is also shown that a unique relationship exists between the 2-port driving-point s parameters in the three configurations, which can be used as a partial check on system accuracy without the need for transformation to 3-port parameters.     

A Novel Approach to Compute Discrete W Transform

The discrete W transform (DWT) is widely used in digital signal processing. This paper proposes a novel approach to compute DWT via computation of the first-order moments without multiplications. A scalable and efficient systolic array is designed to implement this approach. Compared with the other existing methods, the proposed algorithms are simpler and more applicable.     

Estimating Soil Hydraulic Parameters Using Passive Microwave Data

Useful quantitative information about soil properties may be obtained by calibrating energy and moisture balance models with remotely sensed data. In this study, a soil physics model solves heat and moisture flux equations in the soil profile and is driven by the surface energy balance. Model-generated surface temperature and soil moisture and temperature profiles are then used in a microwave emission model to predict the soil brightness temperature. The model hydraulic parameters are varied until the predicted temperatures agree with the remotely sensed measurements. Using this method, values were estimated for hydraulic conductivity, matric potential and soil moisture at saturation, and a soil texture parameter. The conductivity agreed with values measured with an infiltration ring and the other parameters agreed with values in the literature.     

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.     

双端口RAM在主从并行处理系统中的应用

本文介绍双端口ＲＡＭ的特性及使用方法，并给出了在以ＰＣ机为主机，以８０９８单片机为从机的主从式系统中，通过双端口ＲＡＭ实现高速并行通信的应用实例。     

Nonreciprocity in helicon crossed-coil 2-port

Nonreciprocity characteristics observed at room temperature and v.h.f. and higher frequencies in an InSb helicon crossed-coil device are described.     

New technique for 2-port measurement using an 8-port directional coupler

It is shown that the complex scattering parameters of an arbitrary 2-port can be determined using an 8-port microwave network of suitable design and five power sensors.     

A State-Space Approach to Multiuser Parameters Estimation Using Central Difference for CDMA Systems

In this paper, it is shown that a state-space model applies to the code-division multiple-access (CDMA) channel, and Central Difference Filter (CDF) produces channel estimates with the minimum mean-square error (MMSE). This result may be used as compare to Extended Kalman Filter (EKF) which used as channel estimator in CDMA system. The main purpose of this paper is to compare robustness of channel estimator for realistic rapidly time-varying Rayleigh fading channels. To overcome the highly nonlinear nature of time delay estimation and also improve the accuracy, consistency and efficiency of channel estimation, an iterative nonlinear filtering algorithm, called the CDF has been applied in the field of CDMA System. The proposed channel estimator has a more near-far resistant property than the conventional Extended Kalman Filter (EKF). Thus, it is believed that the proposed estimator can replace well-known filters, such as the EKF. The Cramer-Rao lower bound (CRLB) is derived for the estimator, and simulation result show that it is nearly near-far resistant and clearly outperforms the EKF. Jang Sub Kim was born June 15, 1974, in Yeongdeok, Korea. He received the M.S. degree in school of electrical and computer engineering from Sungkyunkwan University, Seoul, Korea. He is currently with the School of Information and Communication Engineering, Sungkyunkwan University, where he was a Ph. D. student since 1999. His research interests include code-division multiple access, channel estimation, position location, and wireless communications. Seokho Yoon (S‘99–M‘1) received the B.S.E. (summa cum laude), M.S.E., and Ph.D. degrees in electrical engineering from KAIST, Daejeon, Korea, in 1997, 1999, and 2002, respectively. From April 2002 to June 2002, he was with the Department of Electrical Engineering and Computer Sciences, Massachusetts Institute of Technology, Cambridge, MA, and from July 2002 to February 2003, he was with the Department of Electrical Engineering, Harvard University, Cambridge, MA, as a Postdoctoral Research Fellow. In March 2003, he joined the School of Information and Communication Engineering, Sungkyunkwan University, Suwon, Korea, where he is currently an Assistant Professor. His research interests include spread spectrum systems, mobile communications, detection and estimation theory, and statistical signal processing. Dr. Yoon is a member of the IEEK and KICS. He was the recipient of a Bronze Prize at Samsung Humantech Paper Contest in 2000. Dong-Ryeol Shin (M‘97) was born in Seoul, Korea, in 1957. He received the B.S., M.S. and Ph.D degree in electrical engineering from the Sungkyunkwan University in 1980, and the Korea Advanced Institute of Science and Technology (KAIST) in 1982 and the Georgia Institute of Technology in 1992, respectively. During 1992-1994, he had worked for Samsung Data Systems, Ltd., Korea. Since 1994, he has been with network research group at the Sungkyunkwan University, Korea, as a professor. His current research interests include wireless communications and ubiquitous computing.