• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.5 s.347
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• pp.156-161
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• 2006

In this paper, GPS/IMT2000/Wireless LAN compact chip antenna is designed for mobile communication system. The proposed antenna size is $10.2mm{\times}21mm{\times}1mm$. It consists of three meander lines. dual resonance frequencies is achieved by two effective current paths using two meander lines and via. also The parasitic meander line structure is added. The coupling is adjusted by arranging parasitic meander line for triple-band. The fabricated antenna achieve triple-band. The resonance frequencies are 1.672GHz, 2.092GHz, 2.504GHz. The impedance bandwidths of each resonance frequencies are 156MHz, 272MHz, 64MHz. The maximum radiation gains of fabricated antenna are 0.08dBi, 1.67dBi, -1.44dBi. The proposed antenna achieve quasi monopole radiation pattern.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.230-237
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• 2012

The ultrasonic resonance method was applied to detect the disbond interface and empty layer between steel and FRP of the exit cone. The ultrasonic resonance method can easily detect the disbond interface and empty layer by amplifying the ultrasonic signal, but pulse echo method is difficult to distinguish adhesive interface from disbond interface or empty layer. The resonance frequency was predicted using the pressure reflection coefficient of 3-layered medium, and measured from ultrasonic signal of the test block using Fast Fourier Transform. The ultrasonic resonance proved that the predicted resonance frequency was in good agreement with the measured resonance frequency.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.2 s.105
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• pp.178-183
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• 2006

The proposed triple-band compact chip antenna using coupled meander line and stacked meander structure for mobile RFID/PCS/WiBro. The proposed antenna is designed to operate at 900, 1,800, and 2,350 MHz, and is realized by parasitic coupled and stacked a meander line. Meander lines are using extend length of effective current path more than monopole and contribute miniaturization. The coupled meander line controls the excitations of the mobile RFID and PCS, stacked meander line controls the excitation of the WiBro. The fabricated antenna size is $10.98{\times}22.3{\times}0.98\;mm$. The resonance frequencies are 905 MHz, 1.77 GHz and 2.32 GHz. The impedance bandwidths are 24 MHz, 140 MHz and 92 MHz. The maximum gains of antenna are 0.34 dBi, 2.58 dBi and 0.4 dBi at resonance frequencies.

• Proceedings of the Optical Society of Korea Conference
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• 2009.10a
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• pp.386-387
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• 2009

• Korean Journal of Optics and Photonics
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• v.22 no.1
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• pp.40-45
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• 2011

Design and fabrication of a TCRR (Triple-coupler Ring Resonator) filter which can provide a doubled FSR (Free Spectral Range) compared with a conventional DCRR (Double-coupler Ring Resonator) filter, are discussed. Through the use of a polymer material with a good thermo-optic property and with high contrast between core and cladding polymer, a compact TCRR filter composed of straight and curved buried waveguides of small radius is designed and fabricated. The transmission characteristics from the through and drop ports are measured using a tunable laser and a fiber array block, and the FSR is observed to be 4.4 nm, about twice that of DCRR filter, and almost the same as that obtained from the analysis using a transfer matrix method.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.2
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• pp.267-276
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• 1999

A 2 stage 6-pole bandpass filter (BPF) is designed and implemented by using K-band triple-mode cavity. The BPF has an 100MHz bandwidth at the center frequency of 18.5GHz and the response of the filter is Chebyshev function. The cavity filter uses two orthogonal $TE_{113}$ modes and one $TM_{012}$ mode. To obtain a Chebyshev response, the intercavity coupling between the adjacent cavities is accomplished by H-field component of TE modes parallel to slot plate. In this paper, the size and location of intercavity slot are determined by the detailed coupling equation from H-field of TE resonant modes in circular cavity. The measured results agree well with the theoretical one.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.12
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• pp.2210-2216
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• 2007

In this paper, triple-band plastic chip antennas for mobile terminal are investigated. Plastic chip antenna is composed of Foamex material with circle of PVC(Polyvilyl chloride). For its electric characteristics, the dielectric constant is 1.9, the insulation intensity is 112KV/cm. Plastic chip antennas are don't tend to break easily against to external shock, have more gain and efficiency than ceramic chip antennas. Triple-band plastic chip antennas of four type are implemented and experimented. From the experiments results, the antenna resonate at the triple-band, the gain of the antennas has about above -2dB, the pattern is ommidirectional the same as the conventional antennas. So, the antennas realized with Foamex material will be application for mobile phone antenna operated at the triple band which is cellular band and Korea-PCS band and ISM band or the antenna for other wireless communication system.

• Journal of Advanced Navigation Technology
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• v.16 no.3
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• pp.433-439
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• 2012

In this paper, we proposed the triplexer using unit-cell of CRLH transmission line which has a bandpass characteristic to reduce adjacent channel interference. The input impedance of triplexer with each channel filter is operated open-circuit at the resonance frequencies of other channels. Such property is due to the combination a series and parallel resonance circuits of CRLH-TL unit-cell. The measured triplexer results are showed a measured insertion loss of each channel, less than 1.5 dB, matching at each port, less than 15dB and isolation between channel, better than 25 dB. Also, to validate the triplexer, a small signal amplifier with triple-band is designed and tested. the measured amplifier results show good agreements with prediction.

• Korean Journal of Materials Research
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• v.7 no.12
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• pp.1041-1046
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• 1997

본 연구에서는 분자선 에피택시 방법으로 비대칭 AIAs/GaAs(001)이중 장벽, 삼중장벽구조를 성장한 수 이를 이용하여 2단자 소자를 제작하여 전기적 특성을 분석하였다. 에피층은 쌍결정 X-ray회절 분석과 단면투과 전자현미경을 이용하여 결정성 및 격자 정합성을 확인하였다. 전기적 성능을 보다 향상시키기 위해 n-GaAs에 대한 오믹 접촉등의 소자 제작 공정을 최적화하였다. 삼중장벽 구조를 이용하여 제작한 소자의 전기적 특성 연구 결과 두개의 주요 공진 터널링 전류 피크 사이에 X-valley에 의한 구조를 확인할 수 있었으며, 이중 장벽구조에 제2의 양자우물 구조를 첨가함으로써 낮은 전압위치에서 전류 피크가 향상하는 결과를 얻었다.

• Journal of IKEEE
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• v.22 no.1
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• pp.127-135
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• 2018

This paper was studied the tri-band folded monopole antenna design with Mu-negative metamaterial unit cell, which operates at 700 MHz UHD broadcast band and 2.45 GHz/5 GHz WiFi band. The MNR metamaterial is fabricated by forming a capacitor on the backside of the antenna substrate and connecting it to the ground plane through a strip line and a via hole so that a single cell can operate in the MZR (Mu zero resonator). Through this, the resonance point can be controlled to resonate in the zero mode in 700 MHz band, and the bandwidth is improved. Experimental results show that the 10dB bandwidth and gain are 309 MHz (41.2%) and 5.298 dB at the first resonance point, and the 10dB bandwidth and gain at the second resonance point are 821.9 MHz (33.5%) and 2.7840 dB respectively. At the third resonance point, the gain and bandwidth were 1.1314 GHz (20.6%) and 2.9484 dB respectively. We confirmed that the resonance point with theoretical value is in agreement with experimental value. And the radiation pattern is generally omnidirectional, and it has been confirmed that the radiation pattern is good in both forward and backward directions at 0.75 GHz and 2.45 GHz, and has a radiation pattern with multiple lobes at 5.5 GHz.