• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.11 s.102
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• pp.1099-1105
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• 2005

TRL error correction method is widely used for measuring high frequency device mounted on PCB. In order to correct error more precisely, the characteristic impedance of standard transmission line should be known mounted for error correction. The capacitance per the unit length of transmission line is calculated by using standard transmission line which terminate resistor additionally at previous method and the characteristic impedance of standard transmission line is calculated with fitting method according to frequency, but the characteristic impedance extracted by a manufacturing inaccuracy is influenced. In this study, a novel method can reduce the manufacturing inaccuracy using measured s-parameters and can extract more accurate characteristic impedance than the previous method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.291-294
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• 2003

The circuit substrate was made from the Low Temperature Cofired Ceramics(LTCC) that a $\varepsilon_\gamma$ was 7.8. Accumulated Varactor and the low noise transistor which were a Surface Mount Device-type element on LTCC substrate. Let passive element composed R, L, C with strip-line of three dimension in the multilayer substrate circuit inside, and one structure accumulate band-pass filter, resonator, a bias line, a matching circuit, and made it. Used Screen-Print process, and made Strip-line resonator. A design produced and multilayer-type VCO(Voltage Controlled Oscillator), and recognized a characteristic with the Spectrum Analyzer which was measurement equipment. Measured multilayer structure VCO is oscillation frequency 1292[MHz], oscillation output -28.38[dBm], hamonics characteristic -45[dBc] in control voltage 1.5[V], A phase noise is -68.22[dBc/Hz] in 100 KHz offset frequency. The oscillation frequency variable characteristic showed 30[MHz/V] characteristic, and consumption electric current is approximately 10[mA].

• Journal of IKEEE
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• v.23 no.2
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• pp.474-478
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• 2019

In this paper, we analyze the degradation of receiving sensitivity due to the coupling between digital noise and mobile handset antenna using characteristic mode. First, we analyze the coupling mechanism between the antenna and digital noise, and analyze the role of the decoupling capacitor of the ground signal line, which is one of the ways to improve the antenna receiving sensitivity degradation due to camera noise. For the analysis, the digital signal line and the ground line of the FPCB of the camera module are modeled as a loop type feeder that excites the characteristic mode of the PCB ground, and improved model which has a ground line with a capacitor are analyzed.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.10
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• pp.39-47
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• 1994

In this paper, by modeling the Multilayer-Multiconductor Transmission Line(MMTL) with the characteristic parameters-effective dielectric constant, eigen modal voltages, characteristic impedances at each mode, pulse propagation characteristics of MMTL network are simulated. Transmission line modelling is performed in frequency domain, then time domain resposes are obtained by transforming the frequency domain response using fast Fourier transform.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2541-2548
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• 2010

This paper describes the calculation for characteristic impedance of transmission line with periodic structures such as defected ground structure (DGS) and photonic bandgap (PBG). The previous method which uses the ${\lambda}$/4 transmission line model is reviewed and its disadvantage that the calculated characteristic impedance is strongly dependent on the frequency is discussed. The characteristic impedance of transmission lines with periodic structures are calculated using the ${\lambda}$/4 transmission line model and analytic method. The calculated characteristic impedance by the latter method is an almost constant value while that from the first method depends on the frequency strongly. In addition, the characteristic impedance of the transmission line with PBG is calculated and proposed, while it has been rarely studied ever. S-parameters are obtained from the measurement using the fabricated sample as well as simulation, and used for calculating the characteristic impedances and comparison. The characteristic impedances calculated from the measured S-parameters agree well with the simulated results. It is well described that the analytic method to calculate the characteristic impedance of transmission lines on uniform dielectric structures can be applied successfully to the transmission lines with periodic structures such as DGS and PBG.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.7
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• pp.316-321
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• 2002

In this Paper, the channel characteristics of the medium voltage(22.9kV) power line to analysis the broadband power line communication in the frequency range up to 30MHz was measured. With the sideband electrical coupler in the operating frequency range from DC to 30MHz, we measured characteristic impedance, noise and attenuation of the medium voltage power line, and then characteristic impedance was measured at the state of unloaded medium voltage power line by Scattering parameter method of Vector Network Analyzer. As a measurement result, Channel impedance shows 100~380$\Omega$ at the less than 15MHz and 70~230$\Omega$ at the more than 15 MHz. Noise characteristics of power line shows -75dBm at 20MHz and Narrowband interference noise was from 3 MHz to 7MHz.

• The Journal of the Acoustical Society of Korea
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• v.10 no.5
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• pp.5-10
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• 1991

본 연구에서는 알루미늄 금속의 결합 검출을 위한 meander line 형 EMAT를 모의 실험을 통해 설계하고 그 대역특성을 연구분석 하였다.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.1
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• pp.159-165
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• 2009

In this study, using a periodical ground structure(PGS) on GaAs monolithic microwave integrated circuit(MMIC), transmission line with a high isolation characteristic was developed for application to compact signal/bias lines of highly integrated MMIC. And the origin of the high isolation characteristic was theoretically investigated. The high isolation characteristic was originated from a resonance between adjacent microstrip lines employing PGS. With only a spacing of $20{\mu}m$, the coupled microstrip line employing PGS showed an isolation value of -47 dB at 60 GHz. The frequency range for high isolation was easily controlled by changing the PGS structure. Above results indicate that microstrip lines employing PGS are very useful for application to compact signal/bias lines of highly integrated MMIC requiring a high isolation characteristics between lines. In addition, equivalent circuit employing closed-form equation for the coupled line with PGS was also extracted.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.238-240
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• 2017

Balun using a coaxial lines i often used in microwave circuits due to easy fabrication, high operating power, and stable operation. However, it is difficult to predict an accurate balun operation characteristic due to the parasitic reactance component to be generated when the coaxial line is connected to the microstrip line existing on the substrate, and the inductance and the capacitance component of the coaxial line itself. In this paper, it is measured the phase characteristics at two output ports of the coaxial line balun which should have opposite phase characteristics. Based on these results, it will examine closely the feasibility of making more improved coaxial line balun.

• Nuclear Engineering and Technology
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• v.42 no.4
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• pp.426-433
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• 2010

The characteristic X-rays emitted from materials after gamma ray exposure was simulated and measured. A CdTe semiconductor detector and a $^{57}Co$ radiation source were used for energy spectroscopy. The types of materials could be identified by comparing the measured energy spectrum with the theoretical X-ray transition energy of the material. The sample composition was represented by the $K_{\alpha1}$-line (Siegbahn notations), which has the highest intensity among the characteristic X-rays of each atom. The difference between the theoretic prediction and the experimental result of K-line measurement was < 0.61% even if the characteristic X-rays from several materials were measured simultaneously. 2D images of the mixed materials were acquired with very high selectivity.