• Title, Summary, Keyword: S-parameter

Search Result 5,266, Processing Time 0.049 seconds

An Analysis of Bias-Dependent S11-Parameter in Multi-Finger MOSFETs (Multi-Finger MOSFET의 바이어스 종속 S11-파라미터 분석)

  • Ahn, Jahyun;Lee, Seonghearn
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.53 no.12
    • /
    • pp.15-19
    • /
    • 2016
  • The gate bias dependence of kink phenomenon with a large deviation from the resistance circle in Smith chart is observed in the frequency response of $S_{11}$-parameter for large multi-finger RF MOSFETs. For the first time, this bias dependence is analyzed by measuring magnitude and phase of $S_{11}$-parameter, input resistance and input capacitance. As a result, $V_{gs}$ dependent $S_{11}$-parameter is largely changed by the magnitude of input capacitance as well as dominant pole and zero frequencies of input resistance. At $V_{gs}=0V$, the kink phenomenon occurs in the high frequency region because of very small phase difference of $S_{11}$-parameter and high pole frequency of input resistance. However, the kink phenomenon at higher $V_{gs}$ is generated in the low frequency region owing to large phase difference and low pole frequency.

Calculation of Interaction Parameters in Mixed Layer Minerals and their Application (층상형 혼합광물의 상호작용계수의 계산 및 응용)

  • 이성근;김수진
    • Journal of the Mineralogical Society of Korea
    • /
    • v.10 no.2
    • /
    • pp.97-104
    • /
    • 1997
  • Based on the method of determination for relative stability of each phase from the difference among the interaction parameters of the phases consisting the mixed layer, the types of interactions between layers were specified and interaction parameter between layers in ordered domain was analytically derived as a function parameter between layers in ordered domain was analytically derived as a function of not only temperature and mole fraction of layers but also ordering parameter. Interaction parameter between the different layers in ordered phase, L is as follows:{{{{ {L }_{1 } (X,Q,T)= { C} over { Q} -4(1-2Q) { L}^{2 } - { RT} over {2} ln { 1} over {2 } - { 2RT} over { { X}_{ s} } ln { { 4QX}`_{s } ^{2 } } over {(1- { X}_{s }- { QX}_{s })( { X}_{s }- {QX }_{s } ) } }}}}L2 is the interaction parameter between ordered and disordered phase in domain and is the mole fraction of the domain which represent the infinite length of mixed layer mineral and Q and C are the reaction progress parameter and arbitrary constant, respectively. This equation was used for the I/S mixed layer clay minerals to infer the relative stability of R1 type I/S mixed layer in the temperature range from 373K to 450K. The result of calculation suggest that, owing to the decrease in interaction parameter with increasing temperature. The interaction parameter decreases more rapidly with decreasing mole fraction of smectite in domain, which is consistent with the fact that the probability of finding the series smectite layer is lo in the domain with small mole fraction of smectite layers in natural system.

  • PDF

FATIGUE DAMAGE PARAMETER OF SPOT WELDED JOINTS UNDER PROPORTIONAL LOADING

  • KANG H. T.
    • International Journal of Automotive Technology
    • /
    • v.6 no.3
    • /
    • pp.285-291
    • /
    • 2005
  • In this paper, the author proposes a fatigue damage parameter of spot welded joints under proportional loading. The proposed fatigue damage parameter is developed based on von Mises' equivalent stress and local structural stress at the edge of spot weld nugget. The structural stress at the edges of the weld nugget in each sheet is calculated using the forces and moments that are determined by finite element analysis. A structural equivalent stress is then calculated by von Mises' equivalent stress equation. The structural equivalent stresses are correlated to experimental fatigue life of the spot welded joints. The proposed parameter is evaluated with fatigue test data of spot welds subjected to multi axial and tensile-shear loads. Sheppard's parameter and Rupp and co-workers' parameter are also evaluated with the same test data to compare with the author's parameter. This proposed parameter presents a better correlation with experimental fatigue data than those of Sheppard's and Rupp and co-workers' parameter. The proposed parameter should be very effective for durability calculations during the early design phase since coarsely meshed finite element models can be employed.

Method for High Frequency Modeling of Transformers Using the S-Parameter (S-Parameter를 이용한 변압기의 고주파 모델링 기법)

  • Jung, Hyeonjong;Yoon, Seok;Kim, Yuseon;Bae, Seok;Lim, Yeongseog
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.29 no.9
    • /
    • pp.677-684
    • /
    • 2018
  • In this paper, we propose a method for high-frequency modeling of transformers using the S-parameter. The open and short circuits of the primary and secondary sides were configured, and the reflection coefficient in each circuit was measured using a vector network analyzer. The equivalent circuit elements were extracted from the measured results to model the high-frequency equivalent circuit, and the validity of the method was verified by comparing the measured S-parameters in a 2-port network with the simulation results.

Measurement and Analysis of Gate Finger Number Dependence of Input Resistance for Sub-micron MOSFETs (Sub-micron MOSFET을 위한 입력 저항의 게이트 핑거 수 종속성 측정 및 분석)

  • Ahn, Jahyun;Lee, Seonghearn
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.51 no.12
    • /
    • pp.59-65
    • /
    • 2014
  • Two input resistances converted from $S_{11}$-parameter and $Z_{11}$-parameter of MOSFETs with various gate finger numbers Nf were measured in low frequency region. The 1/Nf dependent input resistance from $S_{11}$-parameter exhibits much lower values than that from $Z_{11}$-parameter in the range of $Nf{\leq}64$. This 1/Nf dependence was theoretically verified by using Nf dependent nonlinear equation derived from a MOSFET equivalent circuit.

Simulation Input Modeling : Sample Size Determination for Parameter Estimation of Probability Distributions (시뮬레이션 입력 모형화 : 확률분포 모수 추정을 위한 표본크기 결정)

  • Park Sung-Min
    • Journal of the Korean Operations Research and Management Science Society
    • /
    • v.31 no.1
    • /
    • pp.15-24
    • /
    • 2006
  • In simulation input modeling, it is important to identify a probability distribution to represent the input process of interest. In this paper, an appropriate sample size is determined for parameter estimation associated with some typical probability distributions frequently encountered in simulation input modeling. For this purpose, a statistical measure is proposed to evaluate the effect of sample size on the precision as well as the accuracy related to the parameter estimation, square rooted mean square error to parameter ratio. Based on this evaluation measure, this sample size effect can be not only analyzed dimensionlessly against parameter's unit but also scaled regardless of parameter's magnitude. In the Monte Carlo simulation experiments, three continuous and one discrete probability distributions are investigated such as ; 1) exponential ; 2) gamma ; 3) normal ; and 4) poisson. The parameter's magnitudes tested are designed in order to represent distinct skewness respectively. Results show that ; 1) the evaluation measure drastically improves until the sample size approaches around 200 ; 2) up to the sample size about 400, the improvement continues but becomes ineffective ; and 3) plots of the evaluation measure have a similar plateau pattern beyond the sample size of 400. A case study with real datasets presents for verifying the experimental results.

A Parameter Extraction Method for BJT Gummel-Poon Model (BJT Gummel-Poon 모델 파라미터 추출 방법)

  • 윤신섭;이성현
    • Proceedings of the IEEK Conference
    • /
    • /
    • pp.763-766
    • /
    • 2003
  • A direct parameter extraction method using several two-port parameter equations derived in cutoff and active bias modes has been studied to obtain an accurate Gummel-Poon BJT model. First, dc model parameters were extracted from slopes and y-axis intercepts of I-V curve and Gummel plot. The pad capacitances and junction capacitance parameters were determined by using measured S-parameter sets in the cutoff bias. The resistance and transit time parameters were extracted by using measured S-parameter sets in the active bias.

  • PDF

Computer Simulation for the Crossing Time in the Three-State Coupled Discrete-Time, Mutation-Selection Model in an Infinitely Large Asexual Population

  • Lee, Kyu Sang;Gill, Wonpyong
    • New Physics: Sae Mulli
    • /
    • v.67 no.6
    • /
    • pp.776-785
    • /
    • 2017
  • Most previous studies have focused on the two-state, haploid, coupled, discrete-time, mutation-selection (HCDMS) model. The present study examined the error threshold in the n-state HCDMS model in an infinitely large asexual population. The error threshold in a sharply-peaked landscape in the n-state HCDMS model is given as k/(n - 1) when $k{\ll}1$, where k is the fitness parameter. The crossing time in an asymmetric sharply-peaked landscape in the three-state HCDMS model was calculated by grouping the alleles into two-dimensional classes. The crossing time became saturated at a large fitness parameter when s > 0, scaled as a power law in the fitness parameter when s = 0, and diverged as the fitness parameter approached the critical fitness parameter when s < 0, where s is the selective advantage. The crossing time for the fixed extension parameter in the three-state model was saturated at a long sequence length when s > 0 and increased exponentially with increasing sequence length when s = 0. The method developed in this study can be extended to the four-state model describing four different nucleotides for a real DNA sequence.

Prediction of visual search performance under multi-parameter monitoring condition using an artificial neural network (뉴럴네트?을 이용한 다변수 관측작업의 평균탐색시간 예측)

  • 박성준;정의승
    • Proceedings of the ESK Conference
    • /
    • /
    • pp.124-132
    • /
    • 1993
  • This study compared two prediction methods-regression and artificial neural network (ANN) on the visual search performance when monitoring a multi-parameter screen with different occurrence frequencies. Under the highlighting condition for the highest occurrence frequency parameter as a search cue, it was found from the requression analysis that variations of mean search time (MST) could be expained almost by three factors such as the number of parameters, the target occurrence frequency of a highlighted parameter, and the highlighted parameter size. In this study, prediction performance of ANN was evaluated as an alternative to regression method. Backpropagation method which was commonly used as a pattern associator was employed to learn a search behavior of subjects. For the case of increased number of parameters and incresed target occurrence frequency of a highlighted parameter, ANN predicted MST's moreaccurately than the regression method (p<0.000). Only the MST's predicted by ANN did not statistically differ from the true MST's. For the case of increased highlighted parameter size. both methods failed to predict MST's accurately, but the differences from the true MST were smaller when predicted by ANN than by regression model (p=0.0005). This study shows that ANN is a good predictor of a visual search performance and can substitute the regression method under certain circumstances.

  • PDF

Structure Parameter Change Estimation of a Forward Osmosis Membrane Under Pressurized Conditions in Pressure-assisted Forward Osmosis (PAFO) (가압형 정삼투 시 압력에 따른 정삼투막의 Structure Parameter 변화양상 예측)

  • Kook, Seungho;Kim, Sung-Jo;Lee, Jinwoo;Hwang, Moonhyun;Kim, In S.
    • Membrane Journal
    • /
    • v.26 no.3
    • /
    • pp.187-196
    • /
    • 2016
  • Pressure-assisted forward osmosis (PAFO) process has recently been under spotlight for its potential to improve forward osmosis (FO) process performance by applying low hydraulic pressure on the feed side. Structure parameter, one of the governing factors in estimating water flux and solute flux across FO membranes in the solution-diffusion model (S-D model), determines solute resistivity in FO and PAFO processes. This study aims to estimate the trend of structure parameter change with respect to varying additional hydraulic pressure condition in PAFO.