• 한국정보통신설비학회:학술대회논문집
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• 2004.08a
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• pp.369-372
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• 2004

In this paper, a low noise amplifier (LNA) in receiver of Low Noise Block Down Converter (LNB) for direct broadcasting service (DBS) is implemented by using GaAs HEMT The LNA is designed for operation between 10.7GHz-12.7GHz. The LNA consists of input, output matching circuits, DC-blocks and RF-chokes. The result of simulation of the LNA shows that a noise figure is less than 1.4dB and a gain is gloater than 9.2dB in the bandwidth of 10.7 to 12.7GHz with good flatness of 0. ldB

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1712-1714
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• 2001

This paper deals with the development and application of an inner corrosion detector for the ACSR(Aluminum Conductor Steel Reinforced) power lines. The detector runs on an ACSR power line and inspects the inner corrosion of the conductor using the technology of the nondestructive eddy current test. It is consists of an ECT sensor, signal processing units, a RF transmitter/receiver, and etc.. The experimental result through field tests shows the detector can efficiently find both the zinc and aluminum loss of ACSR power lines.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.8 s.197
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• pp.41-49
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• 2007

In this paper, we proposed a new ultrasonic distance measurement system with high accuracy and long range. To improve accuracy and enlarge range, the time of flight of ultrasonic is calculated by the period detecting method. In the proposed ultrasonic distance measurement system, the ultrasonic transmitter and receiver are separated but synchronized by RF(Radio frequency) module. The experiment has been implemented from short distance 1m to maximum available distance 30m. And the period detecting method is compared with the conventional threshold level method. Experimental results show the accuracy and range of the distance measurement are improved by this period detecting method.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.1
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• pp.29-33
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• 2014

This paper proposes an alternate time-switched space-frequency block coding transmission technique for single-carrier modulation with frequency domain equalization. There are two antennas in the transmitter but it still has only a baseband and RF and a switch that alternates between the antennas at every symbol timing. Alternating transmit symbols result in zeros which make maximal ratio receive combining possible in the receiver. Simulation results show that it has better performance than the traditional algorithm at the expense of one additional antenna.

• Journal of Korea Society of Industrial Information Systems
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• v.11 no.1
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• pp.7-12
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• 2006

In this paper, we develop a control system with fire receiver and emergency light that controls (manages) emergency door by wireless signals which prevents crime but also helps evacuate in (fire) emergency. This automatic door operator can be installed on any buildings which have a problem of opening or shutting emergency doors, and it is especially good for buildings with high fire vulnerabilities such as complex buildings, apartments and multistoried buildings without easy control of rooftop doors.

• Progress in Superconductivity
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• v.9 no.2
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• pp.157-161
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• 2008

Due to high speed operations and ultra low power consumptions RSFQ logic circuit is a very good candidate for future electronic device. The focus of the RSFQ circuit development has been on the advancement of analog-to-digital converters and microprocessors. Recent works on RSFQ ALU development showed the successful operation of an 1-bit block of ALU at 40 GHz. Recently, the study of an RSFQ analog-to-digital converter has been extended to the development of a single chip RF digital receiver. Compared to the voltage logic circuits, RSFQ circuits operate based on the pulse logic. This naturally leads the circuit structure of RSFQ circuit to be pipelined. Delay time on each pipelined stage determines the ultimate operating speed of the circuit. In simulations, a two junction Josephson transmission line's delay time was about 10 ps, a splitter's 14.5 ps, a switch's 13 ps, a half adder's 67 ps. Optimization of the 4-bit ALU circuit has been made with delay time consideration to operate comfortably at 10 GHz or above.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.3
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• pp.622-628
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• 1996

This paper describes a new serial interface system which uses conventional 75 ohm coaxial cable. Typically parallel 25 pin cable and connectors are used to transfer and receive the data between digital systems such as HDVCR, D3 VTR and HDTV Receiver. The coaxial cable is more desirable for consumer product applications and also for studio applications where long signal paths and switching are required. This serial data transfer technique is thoroughly tested and utilied in the data transmission/reception between systems more than 200 feet apart. It is also cost effective because it does not require RF PLL, SCRAMBLING, and NRZI hardware.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2371-2373
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• 1999

This paper deals with the development, reliability, specification and performances of the ACSR inner corrosion detector system. It is designed to run on ACSR automatically and to inspect the corrosion of the line with on-line continuously. And it comprises a sensor a constant current source, a signal processing unit, a RF transmitter and receiver unit. Also separable encircling coil sensor is proposed in order to detect inner corrosion of the overhead ground wires. In conclusion, this detector can realize the nondestructive detecting of an ACSR inner corrosion.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.7
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• pp.1814-1819
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• 1996

This paper describes a dnw serial interface system which uses comma free code. Typically parallel 25 pin cable and connectors are used to transfer and receive the data between digital systems such as HDVCR, D3VTR and HDTV Receiver.The coaxial cable is more desirable for consumer product applications and also for studio applications where long signal paths and switching are requeired. This serial data trasfer technique is possible the error detection and the self synchronization, also easy edge insertion for PLL control. It is also cost effective because is does not requeire RF PLL, scrambling, and NRZI hardware.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.2
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• pp.100-105
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• 2006

In this paper, a low noise amplifier(LNA) in a receiver of a low noise block down converter (LNB) for direct broadcasting service(DBS) is implemented using GaAs HEMT. The LNA is designed for the bandwidth of 11.7 GHz-12.2 GHz. The two-stage LNA consists of a input matching circuit, a output matching circuit, DC-blocks and RF-chokes. Experimental results of the LNA show the noise figure less than 1.4 dB, the gain greater than 23 dB and the flatness of 1 dB in the bandwidth of 11.7 to 12.2 GHz.