• Title/Summary/Keyword: Equivalent circuit model

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A Study on the Design of 26GHz Band Thin Duplexer (26GHz 대역 박막 Duplexer 설계에 관한 연구)

  • Yoon Jong-nam;Lee Hyun-Ju;Oh Young-Bu;Lee Cheong-Won;Kim Ki-Don;Lee Jeong-Hae
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2003.11a
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    • pp.208-213
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    • 2003
  • In this paper, we have designed the duplexer using non-radiative dielectric (NRD) guide in millimeter band. The designed duplexer is composed of two stepped-impedance filters and T-junction. Stepped-impedance filters are designed with an equivalent circuit model of evanescent waveguide and the T-junction is optimized to minimize return loss. The characteristics of duplexer shows a good agreement with the expected results.

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Investigation on the Electromagnetic Characteristics of CMOS Rectangular Spiral Inductors according to the Geometrical Change (CMOS 직사각형 나선 인덕터의 기하학적 변화에 따른 전자기적 특성에 관한 연구)

  • Jin Kyoung-Shin;Kim Young-Sik
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.41 no.12
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    • pp.125-130
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    • 2004
  • The characteristics of on-chip spiral rectangular inductors in CMOS process are investigated through the simulation and experiment. The ADS-momentum is used for EM simulation, and the spiral inductors are fabricated with Hynix 0.35㎛ CMOS process. This research mainly concerned the effects of the geometric change in terms of the number of turns and the width of micro strip line. The measured and simulated results show that the Hynix 0.35㎛ process could support a top metal spiral inductor of 1nH to 6nH with Q-factor less than 5.

Impedance Spectroscopy Studies on Corrosion Inhibition Behavior of Synthesized N,N’-bis(2,4-dihydroxyhydroxybenzaldehyde)-1,3-Propandiimine for API-5L-X65 Steel in HCl Solution

  • Danaee, I.;Bahramipanah, N.;Moradi, S.;Nikmanesh, S.
    • Journal of Electrochemical Science and Technology
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    • v.7 no.2
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    • pp.153-160
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    • 2016
  • The inhibition ability of N,N-bis(2,4-dihydroxyhydroxybenzaldehyde)-1,3-Propandiimine (DHBP) as a schiff base against the corrosion of API-5L-X65 steel in 1 M HCl solution was evaluated by electrochemical impedance spectroscopy, potentiodynamic polarization and scanning electron microscopy. Electrochemical impedance studies indicated that DHBP inhibited corrosion by blocking the active corrosion sites. The inhibition efficiency increased with increasing inhibitor concentrations. EIS data was analysed to equivalent circuit model and showed that the charge transfer resistance of steel increased with increasing inhibitor concentration whilst the double layer capacitance decreased. The adsorption of this compound obeyed the Langmuir adsorption isotherm. Gibbs free energy of adsorption was calculated and indicated that adsorption occurred through physical and spontaneous process. The corrosion inhibition mechanism was studied by potential of zero charge. Polarization studies indicated that DHBP retards both the cathodic and anodic reactions through adsorption on steel surface. Scanning electron microscopy was used to study the steel surface with and without inhibitor.

A Study on the Single Line-to-Ground Fault Analysis of HTS Power Cable (초전도 전력케이블의 1선 지락고장 특성 해석에 관한 연구)

  • Je, Hyang-Ho;Bang, Jong-Hyun;Kim, Jae-Ho;Sim, Ki-Deok;Jo, Jeon-Wook;Jang, Hyun-Man;Lee, Su-Kil;Park, Min-Won;Yu, In-Keun
    • Proceedings of the KIEE Conference
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    • 2006.07b
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    • pp.1259-1260
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    • 2006
  • High temperature superconducting(HTS) power cable is expected to be used for power transmission lines supplying electric power for densely populated cities in the near future. Commercializing of HTS power cable is coming. Simulation is required for safety before install of HTS power cable, a fabrication model used at the power system simulation. In this paper, we shows a single line-to ground fault analysis in the grid system which has a 100m length HTS power cable. The authors developed a single line-to-ground fault current calculation method which is considering the shield layer of HTS power cable. In the calculation, the T type equivalent circuit is used to derive the mutual inductance of the HTS power cable.

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Characterization of a LSCF/GDC Cathode Composite in Solid Oxide Fuel Cells Using Impedance Spectroscopy

  • Hwang, Jin-Ha;Lee, Byung-Kook
    • Journal of the Korean Ceramic Society
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    • v.42 no.12 s.283
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    • pp.793-799
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    • 2005
  • A composite cathode of LSCF$(La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_3)\;and\;GDC\; (Gd_2O_3-doped\;CeO_2:Ce_{0.9}Gd_{0.1}O_{1.95_})$ was characterized in terms of an electrode response, using a point contact in an Yttria-Stabilized Zirconia (YSZ) electrolyte incorporated into AC two-point impedance spectroscopy. The point-contacted configuration amplifies the responses occurring near the YSZ/cathode interface through the aligned point contact on the planar LSCF/GDC electrode. The point contact interface increases the bulk resistance allowing the estimation of the point contact geometry and resolving the electrode-related responses. The resultant impedance spectra are analyzed through an equivalent circuit model constructed by resistors and constant phase elements. The bulk responses can be resolved from the electrode-related portions in terms of spreading resistance. The electrode-related polarizations are measured in terms of temperature and oxygen partial pressure. The modified impedance spectroscopy is discussed in terms of methodology and analytical aspects, toward resolving the electrode-polarization issues in solid oxide fuel cells.

A Prediction of Radiation Power for the Planar Array Acoustic Transducer Considering Mutual Coupling Effects (상호 간섭 영향을 고려한 평면 배열형 음향 트랜스듀서의 방사 출력 예측)

  • Lee, Jong-Kil;Seo, In-Chang
    • The Journal of the Acoustical Society of Korea
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    • v.15 no.1
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    • pp.17-22
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    • 1996
  • Planar array of acoustic transducer is normally used in a sonar system. Acoustic radiation makes beam pattern in underwater uses. The main source of the beam pattern is due to the transducer array. Therefore, estimation of the acoustic radiated power is necessary to predict the performance and efficiency of the transducer. As an example of the acoustic radiation power, nine acoustic transducers mounted to a rigid infinite baffle are considered in a theoretical model. Each piston's acoustic radiation consists of self- and mutual-radiation impedances. Total radiation impedances and acoustic radiation power of the transducers are extracted using on the theory of an equivalent electric circuit. The theoretical results reveal that acoustic radiation power of the transducer depends on the mutual coupling effects.

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Electrode Charging Effect on Ion Energy Distribution of Dual-Frequency Driven Capacitively Coupled Plasma Etcher (이중 주파수 전원의 용량성 결합 플라즈마 식각장비에서 전극하전에 의한 입사이온 에너지분포 변화연구)

  • Choi, Myung-Sun;Jang, Yunchang;Lee, Seok-Hwan;Kim, Gon-Ho
    • Journal of the Semiconductor & Display Technology
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    • v.13 no.3
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    • pp.39-43
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    • 2014
  • The effect of electrode charging on the ion energy distribution (IED) was investigated in the dual-frequency capacitively coupled plasma source which was powered of 100 MHz RF at the top electrode and 400 kHz bias on the bottom electrode. The charging property was analyzed with the distortion of the measured current and voltage waveforms. The capacitance and the resistance of electrode sheath can change the property of ion and electron charging on the electrode so it is sensitive to the plasma density which is controlled by the main power. The ion energy distribution was estimated by equivalent circuit model, being compared with the measured distribution obtained from the ion energy analyzer. Results show that the low frequency bias power changes effectively the low energy population of ion in the energy distribution.

Effect of Permeability and Piezomagnetic Coefficient on Magnetostrictive/Piezoelectric Laminate Composite

  • Wu, Zhiyi;Wen, Yumei;Li, Ping;Yang, Jin;Dai, Xianzhi
    • Journal of Magnetics
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    • v.16 no.2
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    • pp.157-160
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    • 2011
  • The magnetostrictive material is magnetized in magnetic field and produces a nonuniform demagnetizing field inside and outside it. The demagnetization is decided by the permeability of magnetostrictive material and its size. The magnetoelectric performances are determined by the synthesis of the applied and demagnetizing fields. An analytical model is proposed to predict the magnetoelectric voltage coefficient (MEVC) of magnetostrictive/piezoelectric laminate composite using equivalent circuit method, in which the nonuniform demagnetizing field is taken into account. The theoretical and experimental results indicate that the MEVC is positively connected with the permeability and the piezomagnetic coefficient of magnetostrictive material. To obtain the maximum MEVC, both the permeability and the piezomagnetic coefficient of magnetostrictive material should be taken into account in selecting the suitable magnetostrictive material.

Position and Speed Sensorless Vector Control of SynRM for Efficiency Optimization Control (효율 최적화 제어를 위한 SynRM의 위치 및 속도 센서리스 벡터제어)

  • Lee , Jung-Chul;Chung, Dong-Hwa
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.39 no.6
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    • pp.59-70
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    • 2002
  • This paper proposes a position and speed sensorless vector control for Synchronous Reluctance Motor(SynRM) operating at optimum efficiency and high response, in which core loss is taken into account, and discusses the performance of system. The proposed control scheme is based on the flux estimation combined stator voltage and current. In this paper, current angle condition of efficiency optimization which minimizes the copper and iron losses is derived based on the equivalent circuit model of the SynRM. The research result of closed loop position and speed control with efficiency optimization control is given to verify the proposed scheme.

Analysis of Novel Approach to Design of Ultra-wide Stopband Microstrip Low-Pass Filter Using Modified U-Shaped Resonator

  • Karimi, Gholamreza;Lalbakhsh, Ali;Dehghani, Khatereh;Siahkamari, Hesam
    • ETRI Journal
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    • v.37 no.5
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    • pp.945-950
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    • 2015
  • A novel microstrip low-pass filter is presented to achieve an ultra-wide stopband with 11 harmonic suppression and very sharp skirt characteristics. The filter is composed of a modified U-shaped resonator (which creates two fully adjustable transmission zeroes), a T-shaped resonator (which determines a cut-off frequency), and four radial stubs (which provide a wider stopband). The operating mechanism of the filter is investigated based on a proposed equivalent-circuit model, and the role of each section of the proposed filter in creating null points is theoretically discussed in detail. The presented filter with 3 dB cut-off frequency ($f_c=2.35GHz$) has been fabricated and measured. Results show that a relative stopband bandwidth of 164% (referred to as a 22 dB suppression) is obtained while achieving a high figure-of-merit of 15,221.