Mostrando recursos 1 - 20 de 657

  1. A tunable 1.4-2.5GHz bandpass filter based on single mode

    Yanyi Wang; Feng Wei; He Xu; Xiaowei Shi
    Abstract—A new type of varactor-tuned microstrip bandpass filter (BPF) based on a single 1/2λ resonator is investigated. The proposed resonator is composed of a transmission line with both ends short-ended and two varactors inserted symmetrically in the middle section. The variation of coupling coefficient can be controlled by using an inductor. With the proposed structure, it is easy to adjust the external quality factor of the filter and to control the bandwidth. Extra dc-block capacitors for the input and output ports are not necessary because the design of the proposed tunable 1/2λ resonator makes the varactor act as both a...

  2. Study and Application of ESD Generator Modele

    Wang Hui; Tian Wei
    Abstract. Phenomenon of electrostatic hazards is becoming increasingly prominent with wide application of microelectronic elements. Electrostatic Discharge (ESD) is an extremely complex process, which is not only related to the materials, the object shape and the value of discharging circuit resistance, but also always involved in very complicated process of gas breakdown, so ESD is also a stochastic process which is difficult to repeat. According to the request of standard IEC61000-4-2, simulation circuit of the equivalent Human-Metal Model is established, discharging process is simulated and analyzed, and the influence laws of circuit parameters and distribution parameters for ESD current waveform...

  3. Effect of Direct-Current Biasing on the Dielectric Properties of Barium Strontium Titanate

    Jih-wei Liou; Bi-shiou Chiou
    Ba1-xSrxTiO3 (BST, x = 0 to x = 1) ferroelectric ceramics doped with 1.0 mol % MgO and 0.05 mol % MnO2 were prepared with a rate-controlled sintering profile. As the strontium molar fraction x increased, the average grain size decreased from 14 µm for x = 0 to 2 µm for x = 1. Tem-perature dependence of the dielectric properties was mea-sured as a function of dc biasing. At 10°C above the Curie temperature, the changes of dielectric constant at 5000 V/ cm were 28%, 17%, 26%, and 36 % for x = 0, 0.25, 0.5, and 0.75, respectively....

  4. Dual Transmission Line with Charge-transfer Resistance for Conducting Polymers

    W. John Albery; Andrew R. Mountt
    To describe charge conduction in conducting polymers a dual transmission line with one resistance describing electronic motion in the polymer and a second resistance describing ionic motion in the pores has proved applicable to a number of systems. A further feature of ac impedance plots for these polymers is a high-frequency semicircle. This may be attributed to a charge-transfer resistance and double-layer capacitance at either the electrode/polymer or the polymer/electrolyte interface. A general expression for such a charge-transfer resistance is derived and it is shown that the current will be proportional to the difference in Nernst potential across such a...

  5. Characteristics of Linear Induction Motor Considering Material of Reaction Plate Change

    Meng Li; Zhongping Yang; Fei Lin; Hu Sun
    Abstract—In this paper, a method of calculating the parameters of equivalent circuit model of linear induction motor(LIM) is proposed based on numerical analysis and finite element method(FEM). The method is proved accurately through the traditional removed and locked tests. Material change of reaction plate’s effect on how equivalent circuit’s parameters change and the influence on thrust and vertical force are analyzed through this method. The co-simulation of Maxwell and SIMULINK is analyzed. A control algorithm to compensate the effect of material change is presented. The compensation is based on equivalent circuit parameters variation and indirect vector control. Simulation results have...


    Ing Daniel Mika; Doctoral Degree Programme
    In the paper the process of the test controller design and synthesis on register transfer level is described. The principle of circuit element access is discussed during the test plan scheduling. The formal tool – a mathematical logic and a set theory – is used as suitable tool for test controller design process. The problem of I-path is explained and a simple example of I-path was also demonstrated. 1

  7. Design and fabrication of a MEMS capacitive chemical sensor system

    Vishal Saxena; Todd J. Plum; Jeff R. Jessing; R. Jacob Baker
    Abstract — This paper describes the development of a MEMS sensor system to detect volatile compounds. The sensor consists of a MEMS capacitive sensor element monolithically integrated with a sensing circuit. The sensor element is a parallel plate capacitor using a chemically sensitive polymer as the dielectric. In presence of the target analyte, the polymer swells and changes the capacitance of the sensor element. This change in capacitance is sensed and converted to a digital bit stream by a delta-sigma sensing circuit. This paper provides an overview of the design of the sensor element, the sensing circuit and the process...

  8. Intelligent Temperature Controlling System Based on Single Chip Microcomputer

    Xie Fei; Zhong Fei; Ding Shanting; Wang Xuanze
    Abstract.Based on the principle of integral circuit and thermal element, the present study considers the application of 80C51 single-chip micro-computer into the design of intelligent temperature control system. In this paper, the main approach is to make the ambient temperature change in accordance with the pulse width variation. The process is realized through the integral circuit consisting of the thermal resistor, capacitor and operational amplifier. In this way, with the pulse width measurement, we can detect the ambient temperature as well as control the external circuit. The experiment indicated that the system simplifies the temperature measurement with high reliability, great...

  9. Large Signal Characterization and Modeling of G AFOSR-90-0302 Heterojunction Bipolar Transistors PR 2305/Ri a. AUTHORNS)

    U M Is; D. S. Whitefield; C. J. Wei; J. C. M. Hwang
    b~n Toiiovod /1 06..... sol%;- its 91-13063 I & ABSTRACT (M mmum2 00 vm Heterojunction bipolar transistors have been characterized up to 40GHz. In addition to direct current-voltage and high frequency small signal measurements, power and harmonic characterization has been performed. The measurement results were fitted to a ten-element equivalent circuit model in which only three elements were allowed to vary with bias. This bias dependant model is accurite to within 2 % over the entire bias range and is the first step toward a true large-signal model. The power and harmonic characteristics of the heterojunction bipolar transistor can also...

  10. El nacimiento de la deuda aduanera en la Unión Aduanera y en México. Estudio comparado

    Herrera Orozco, Carlos Gerardo
    El artículo 5 del “Acuerdo de Asociación Económica, Concertación Política y Cooperación entre los Estados Unidos Mexicanos y la Comunidad Europea y sus Estados Miembros”, junto con el artículo 17 de la “Decisión 2/2000 del Consejo Conjunto Comunidad Europea – México”, los cuales proponen un programa para establecer las divergencias y similitudes de ambos sistemas, para generar propuestas de aproximación de ambos sistemas aduaneros, fueron la inspiración para realizar esta tesis. En ella realizamos un estudio crítico, descriptivo y analítico de los sistemas jurídicos aduaneros de la Unión Europea y México, con especial énfasis en el nacimiento de la obligación de...

  11. A provably passive and cost-efficient model for inductive interconnects

    Hao Yu; Student Member; Lei He
    Abstract — To reduce the model complexity for inductive interconnects, the vector potential equivalent circuit (VPEC) model was introduced recently and a localized VPEC model was developed based on geometry integration. In this paper, we show that the localized VPEC model is not accurate for interconnects with non-trivial sizes. We derive an accurate VPEC model by inverting inductance matrix under the partial element equivalent circuit (PEEC) model, and prove that the effective resistance matrix under the resulting full VPEC model is passive and strictly diagonal dominant. This diagonal dominance enables truncating small-valued off-diagonal elements to obtain a sparsified VPEC model...

  12. Electrical Parameter Extraction of High Performance Package Using PEEC Method

    This paper proposes a novel electrical characterization approach for a high-performance package system using an improved Partial Element Equivalent Circuit (PEEC). As the effect of interconnects becomes a pivotal factor for the performance of high-speed electronic systems, there is a great demand for an accurate equivalent model for interconnects. In particular, an equivalent model of interconnects is established in this paper for the Fine-Pitch Ball Grid Array (FBGA) package using the improved PEEC method. Based on the equivalent model, electrical charac-teristics are analyzed; furthermore, these are verified through the measurement results of a Vector Network Analyzer (VNA).

  13. Analytical Calculation for DC Inductances of Rectangular Spiral Inductors With Finite Metal Thickness in the PEEC Formulation

    Jen-tsai Kuo; Senior Member; Ke-ying Su; Te-yu Liu; Hao-hui Chen; Shyh-jong Chung
    Abstract—Inductances of rectangular spiral inductors with fi-nite metal thickness are evaluated by the partial element equiva-lent circuit (PEEC) technique. The six fold partial self and mutual inductance integrals resulting from the PEEC partitions are found to have analytical expressions, so that the singularities of the in-tegrands can be overcome and the theoretical or “exact ” results can be obtained very efficiently. Via and underpath required for input/output connection can also be included in the calculation. Calculated inductance values for 20 square spiral inductors are checked against measured data published in open literature. De-pendence of inductance values on metal thickness is...

  14. The Finite Element Analysis of the Leakage Inductance for High Frequency Switching Mode Power Supply Transformer

    Peng Sun; Jun Huang
    Abstract. In order to improve the stability and reliability of switch mode power supply, the mathematical model of high frequency transformer is established with considering the effects of the leakage inductance of the high frequency transformer on the working state of DC-DC full bridge converter circuit. A finite element analysis method for two dimensional transient field circuit directly coupled of transformer in the case of full bridge inverter is proposed. Transformer inductance parameters are calculated using the method of field energy, which may provides the basis for the design of switching mode power supply transformer.

  15. Assessment of Power Losses of an Inverter-Driven Induction Machine With Its Experimental Validation

    Carlos A. Hern; Tim C. Green; Senior Member; Y Smith; Senior Member
    Abstract—Detailed power loss distribution in induction ma-chines is assessed using time-stepped finite-element analysis coupled to circuit equations of an inverter. Losses are examined for various load conditions. Iron losses are largely unexplored and so particular attention is paid to them here. The simulation has revealed the division between ohmic, hysteresis, classic eddy-current, and anomalous losses; and the distribution in the frequency spectrum between fundamental, slotting, and multiples of the switching frequency. Insight is also gained into the spatial location of the loss. Experimental validation is provided for several fundamental frequencies from full-load to light-load conditions. Index Terms—Efficiency, finite element (FE),...


    [pt] Neste material estão apresentados os elementos que compõe a programação do curso de Circuitos Elétricos/Eletrônicos.

  17. Design for Drive Circuit of Solid Micro-thruster Ignition System

    Yang Shen; Zhihua Chen; Zhanqiang Hou; Yaomin Chen
    Abstract. Aiming at the lack of standard design method and the shortcomings of main functions of the existing drive circuit, a “Element-level Design under Transmission Voltage Switch Theory ” is set forth and a smallest circuit structure namely as drive-unit, which contains Superstratum-unit, Substratum-unit and LC-unit, is designed in this paper to achieve the necessary functions. The drive circuit of n×n ignition bridges has been got from the structure expansion formula along with the expected life estimation. The Ebers-Moll Model of transistor and the internal circuit of MOSFET were used to make a theoretical analysis and the conclusion of such...

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    Rainee N. Simons; Richard Q. Lee; Rainee N. Simons; Richard Q. Lee
    A frequency multiplier with active linearly tapered slot antennas (LTSAs) has been demonstrated at the second harmonic frequency. In each antenna element, a GaAs monolithic microwave integrated circuit (MMIC) distributed amplifier is integrated with two LTSAs. The multiplier has a very wide bandwidth and large dynamic range. The fundamental-to-second harmonic conversion efficiency is 8.1 percent. The spatially combined second harmonic signal is 50 dB above the noise level. The design is suitable for constructing a large array using monolithic integration techniques.

  19. Transient electromagnetic field numerical analysis of self-excited retarder

    Yang Xiaojun; A He Ren; B Wang Fan; C Feng Yizeng
    analysis Abstract: Power generation performance of a self-excited retarder determines whether the design goal of its braking torque could be achieved. The numerical analysis of transient electromagnetic field took magnetic vector potential as variable and made six reasonable assumptions to simplify calculation. Based on above, definite solution about transient electromagnetic field and the finite element received a detailed description. The external circuit and end effect of the power generation unit were taken into account so as to improve the calculation accuracy. Let the finite element equation and external circuit equation combine to form field-circuit coupled equations and then using Crank...

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    Agustino Martínez-antonio
    Protein and mRNA levels support the notion that a genetic regulatory circuit controls growth phases in E. coli populations Agustino Martínez-Antonio Bacterial populations transition between growing and non-growing phases, based on nutrient availability and stress conditions. The hallmark of a growing state is anabolism, including DNA replication and cell division. In contrast, bacteria in a growth-arrested state acquire a resistant physiology and diminished metabolism. However, there is little knowledge on how this transition occurs at the molecular level. Here, we provide new evidence that a multi-element genetic regulatory circuit might work to maintain genetic control among growth-phase transitions in Escherichia...

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