• 대한전자공학회논문지TC
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• 제48권7호
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• pp.28-34
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• 2011

영차 공진과 반파장 공진을 이용한 이중 모드 Inductor loaded 패치 안테나의 방사 특성을 연구하였다. 반파장 공진 모드에서 수평방향으로의 방사 이득을 최소화시키는 동시에 전방 방사 이득을 향상시켜 영차 공진 모드 방사 패턴과의 격리도를 향상시켰다. 이중 모드 inductor loaded 패치 안테나 기판의 유전상수가 작을수록, 안테나의 동작 주파수 대역이 높을수록 두 모드 간의 공진 주파수 간격이 증가함을 확인하였다.

• 한국컴퓨터정보학회논문지
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• 제9권4호
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• pp.93-97
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• 2004

본 논문에서는 수분센서용으로 적합한 구조의 안테나로 소형 도체면 구조의 개루우프 안테나를 모델로 제시하고, 그 동작특성을 모멘트법을 이용하여 수치해석하였다. 수치해석 결과 동작주파수 $300{\sim}500[MHz]$ 대역에서 안테나의 파라미터 값들의 변화에 따라 입력임피던스는 $50[{\Omega}]$으로 정합시킬 수 있었으며, 또한 개루우프 반경, 높이, 폭은 안테나의 공진주파수를 변화시키는 파라미터로 작용하였으며, 부하로 사용되는 인덕턴스 값은 안테나의 입력임피던스를 조절할 수 있는 파라미터로 작용하고 있음을 알 수 있었다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 추계종합학술대회
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• pp.211-214
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• 2007

In this paper, the resonance characteristics of ZnO-based film bulk acoustic resonator (FBAR) devices with thick bottom electrode are investigated. The ultra-thin Cr film (300 ${\AA}-thick$) between $SiO_2$ film and W film is formed by a sputtering-deposition in order to enhance the adherence at their interfaces. The resonance frequency of three different resonator devices was observed to be ${\sim}2.7$ GHz, and the resonance characteristics $(S_{11})$ of the FBAR devices were found to have a strong dependence on the thickness of bottom electrode.

• 한국자동차공학회논문집
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• 제16권3호
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• pp.102-110
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• 2008

It is well known that the acoustic cavity inside the tire-wheel assembly contributes to vehicle interior noise and ride comfort. In this paper, we performed acoustic and structural modal testings by varying the temperature ranging from $20^{\circ}\;to\;45^{\circ}C$ to investigate the effects of temperature on acoustic cavity resonance and structural vibration characteristics for unloaded and loaded tires. The testing has given us some findings, which are reported in this paper.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.214-219
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• 2003

Recently, the optical disk drive that is thin in thickness has been demanded by the popularization of notebook PC. The device that controls the thickness of a drive is the height of optical pickup. Therefore, researches about this are going on and an asymmetric actuator is the good choice fur this target. However, the actuator of this design has troubles that a subsidiary resonance is likely to be actuated by discord between the center of force and the mass of renter. In this paper, relation between the tracking coil and the subsidiary resonance is analyzed and dynamic characteristics of an actuator are improved by using experiments design and response surface method.

• Current Optics and Photonics
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• 제2권4호
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• pp.378-382
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• 2018

In most previous investigations of plasmonic and metamaterial applications, the metallic film has been regarded as a perfect electrical conductor. Here we demonstrate the resonance characteristics of THz metamaterials fabricated from metal film that has a finite dielectric constant, using finite-difference time-domain simulations. We found strong redshift and spectral broadening of the resonance as we decrease the metal's plasma frequency in the Drude free-electron model. The frequency shift can be attributed to the effective thinning of the metal film, originating from the increase in penetration depth as the plasma frequency decreases. On the contrary, only peak broadening occurs with an increase in the scattering rate. The metal-thickness dependence confirms that the redshift and spectral broadening occur when the effective metal thickness drops below the skin-depth limit. The electromagnetic field distribution illustrates the reduced field enhancement and reduced funneling effects near the gap area in the case of low plasma frequency, which is associated with reduced charge density in the metal film.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.858-860
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• 2000

Recently, optical pickup actuators have been designed to have structures that extruded lens to decrease their height, because they are used in very thin drive for notebook computers. However because of discordant and undesirable of forces that are supposed to happen in this design feature, subsidiary resonance such as rolling and pitching mode exert bad influence on actuator. In this paper, we presented force constituents to clarify the cause of subsidiary resonance analysis to evaluate characteristics of actuators. As a result. we could find out design parameters to diminish the influence of subsidiary resonance. Sample actuators designed with appropriate parameters were fabricated and put to practical tests. Comparing analysis with experimental results, we verified the accuracy of the analysis and the effectiveness of the method presented.

• 한국전기전자재료학회논문지
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• 제13권7호
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• pp.563-567
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• 2000

We presented the etch results of indium-tin oxide thin films by using SF$_{6}$/O$_2$gas electron cyclotron resonance plasma and conducted X-ray phtoelectron spectroscopy and quadrupole mass spectrometer analyses for the etch characteristics. The etch rate of the films was greatly dependent on that of oxygen which was the major constituent element of the films. The oxygen was removed by the forms like $O_2$or SOF$_2$. We examined the ratio of atomic content of O and In and the change of this ratio was related to the removal rate of InF$_{x}$ and the S-metal bonding.ing.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1366-1367
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• 2006

Embedded capacitor technology is one of the effective packaging technologies for further miniaturization and higher performance of electric package systems. So we used the 3D EM simulator for embedded capacitor design in 8-layed PCB(Printed Circuit Board). The designed capacitors value are 2 pF, 5pF, 10 pF, respectly. we investigated characteristics of capacitance - frequency and SRF(Self Resonance Frequency) as changing the rate of hight and width of upper pad of embedded capacitors.

• Journal of information and communication convergence engineering
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• 제3권1호
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• pp.23-27
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• 2005

In this paper, the effects of various annealing conditions on the resonance characteristics of ZnO-based FBAR devices are compared. Several FBAR device samples were fabricated by using three different annealing methods while one sample remained non-annealed as a reference for comparison. Return loss ($S_11$) could be significantly improved by both Bragg reflector-annealing and/or post-annealing. Especially, the use of the combined annealings resulted in most desirable resonance improvement compared with the Bragg reflector-annealing or post-annealing method alone.