• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.91-96
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• 2017

In this paper, we proposed a meander sleeve monopole antenna for low earth orbit satellite communications. The antenna has broadband property with the planar monopole and ground of meander sleeve. Monopole and ground conductors of the antenna are on the same plane, and exited through coaxial cable feeding. In order to confirm the property of antenna parameters, it was used a commercial software, HFSS, For the antenna fabrication, a FR4 dielectric substrate has a dielectric constant of 4.4 was used. The size of the antenna was $600mm{\times}20mm{\times}1.6mm$. Frequency band of the fabricated antenna was 130MHz~151MHz, and the bandwidth was 20MHz. Measurement results of the fabricated antenna, the return loss is more than -10dB return loss in the band could be obtained. Radiation pattern has a maximum gain of 2.64dBi value.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.268-270
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• 2004

There are various researches on MPEG techniques. MPEG technique is used to digital TV(DTV) and internet image communication. Connection method between server and client is usually using wire. Applications may be expanded, if wireless technology is used between server and client system. In this paper, Bluetooth is used for connection method between server and client. Bluetooth offers fast and reliable transmissions of both voice and data over the globally available 2.4GHz ISM (Industrial, Scientific and Medical) band. One of the major application purposes of Bluetooth is the cable replacement for mobile and peripheral devices. Bluetooth has the advantage of small size, low power and low cost. It has the disadvantage of limited bandwidth and limited range. In order to transfer effectively image Information between server and client using Bluetooth, we apply MPEG-2 and MPEG-4 image compression techniques and the results are compared with each other.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.10a
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• pp.156-159
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• 2001

Recently, side scan sonar system has been developed and operated to survey cable laying, sunken bodies, geometry of sea bottom and so on. It uses the acoustic signals, which are emitted from two transducer arrays, left and right sides, to get geometric information of the specified area. This system consists of transceiver board, towed body, deck unit and GPS receiver. The transceiver board, nested in a watertight canister, controls the transmitting and receiving of the acoustic pulses from transducer arrays. After receiving the scattered signals, it processes BP(Band Pass) filtering, AGC(Automatic Gain Control), TVG(Time Varying Gain) and Heterodyne. The deck init has the signal processing part, A/D converter, power supplier, and real-time monitoring part. The towed body has been designed to satisfy the optimal hydrodynamic behavior during towing, In this paper, brief introductions on the design theory of transceiving part and some results from the field which have been operated recently will be introduced.

• 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.193-197
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• 2006

Radiation properties of flush mounted circular patch antennas are investigated. The patch is fed axis-symmetrically by a coaxial cable. Rigorous analysis iscarried out using integral transform and mode matching techniques. The presented method can accommodate a radiating patch, integrated matching section and band pass filter.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1491-1494
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• 2008

Typically internal mobile LCD display modules are connected to the mobile product baseband PCB with flexible printed circuit board equipped with board-to-board connector. This solution has a drawback of limiting the product concept work to certain solutions that are based on connector size, location, flexible PCB length, bending, etc. in the display module. Also flexible printed circuit board based solutions are not completely optimized from reliability point of view, causing flex circuit board breakings. For the external displays in the PC or Home entertainment market, the cable solution is too expensive and resource demanding. The wireless solution has obvious advantages over reliability, low cost and flexibility. This paper describes a wireless audio-visual interface solution.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.4
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• pp.636-644
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• 1999

Experimental and simulation results are presented on the Aperture-Coupled microstrip patch antennal with U-shaped slot. Experiment and simulation results include impedance bandwidth, copolar and crosspolar-pattern characteristics and gain measurements. Simulation results show the advantages of U-slotted patch antenna comparing with the normal patch antenna. More than 35% impedance bandwidth is obtained with reasonably restricted cross-polar radiation pattern. The U-slotted radiation element fed by aperture-coupling method can be more easily extended to array structure, compared with that fed by coaxial cable.

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.1185-1188
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• 2003

This paper describes a design for a 2.5Gb/s serial data link CMOS transceiver based on the InfiniBand$^{TM}$ specification. The transceiver chip integrates data serializer, line driver, Tx PLL, deserializer, clock recovery, and lock detector. The designed transceiver is fabricated in a 0.25 ${\mu}{\textrm}{m}$ CMOS mixed-signal, 1-poly, 5-metal process. The first version chip occupies a 3.0mm x 3.3mm area and consumes 450mW with 2.5V supply. In 2.5 Gbps, the output jitter of transmitter measured at the point over a 1.2m, 50Ω coaxial cable is 8.811ps(rms), 68ps(p-p). In the receiver, VCO jitter is 18.5ps(rms), 130ps(p-p), the recovered data are found equivalent to the transmitted data as expected. In the design for second version chip, the proposed clock and data recovery circuit using linear phase detector can reduce jitter in the VCO of PLL.L.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.75-78
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• 2000

Since the most of malfunctions in the industrial equipment controlled by processors is occured by the Electrical Fast Transient(EFT), the International Electrotechnical Commission(IEC) prepared the dummy signal to test the immunity level of the equipments. In this paper. we designed a new EMC filter for power line in break-box, which is consist of the feed-through capacitor and ferrite materials with high permeability which was wound or inserted in the second layer of the power cable in order to increase common mode inductance. We have obtained a excellent insertion loss characteristics over wide frequency band from 100 KHz up to 6 GHz. It is expected that the new EMC filter could be effectively used for industrial, MIL, and medical equipments to reduce a malfunctions and be suitable for IEC 61000-4-4.

• Journal of the Semiconductor & Display Technology
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• v.2 no.2
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• pp.9-15
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• 2003

This paper proposes a thickness measurement method of silicon-oxide and poly-silicon film deposited on 12" silicon wafer for spin etcher. Halogen lamp is used as a light source for generating a wide-band spectrum, which is guided and focused on the wafer surface through a optical fiber cable. Interference signal from the film is detected by optical sensor to determine the thickness of the film using spectrum analysis and several signal processing techniques including curve-fitting and adaptive filtering. Test wafers with three kinds of priori-known films, polysilicon(300 nm), silicon-oxide(500 nm) and silicon-oxide(600 nm), are measured while the wafer is spinning at 20 Hz and DI water flowing on the wafer surface. From experiment results the algorithm presented in the paper is proved to be effective with accuracy of maximum 0.8% error.rror.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2000.10a
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• pp.222-227
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• 2000

"Side scan sonar" using acoustic signal has been developed to survey cable laying, sunken bodie\ulcorner bottom and so on. It use the acoustic signals, which are emitted from two transducer arrays, to get gemetri\ulcorner target area. This system consists of transceiver board, towed body, and deck unit. The transceiver board, w\ulcorner watertight canister of the towed body, controls the transmitting and receiving of 400kHz acoustic signals from \ulcorner After receiving the scattered signals, it processes the filtering, AGF(Automatic Gain Control), TVG(Time Heterodyne. The deck unit is composed of the signal processing part, A/D converter, power supplier, and real\ulcorner And the towed body has been designed to satisfy the optimal hydrodynamic behavior during towing. The de\ulcorner theory of transceiving part and some results from field-experiments will be introduced here.