• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.238-241
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• 2001

In this paper, we designed the video transceiver and control data transceiver of ISM bands. They are designed according to the law for radio regulation and can communicate with each other by about 1Km. Also, we developed the remote monitor and control system via radio using designed transceivers for ISM band.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.135-136
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• 2007

2.45 GHz RF Transceiver composed RF module and Digital module for USN(Ubiquitous Sensor Network) has been implemented in this paper. The proposed RF system is designed based on IEEE 802.15.4-2006 PHY standard which has a frequency range from $2.4{\sim}2.4835GHz$. In this transmitter chain, the output power is controlled form 0 to 30 dBm. In this receiver chain, less than 20 dB of NF was obtained.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.436-441
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• 2006

In recent European telecommunication base transceiver stations(BTS) a membrane laminated air filter is reported to replace a heat exchanger in order to cool internal digital units of BTS. The concept of using the air filter is for the direct ambient cooling(DAC) of BTSs without heat loss generally found ill the heat exchanger type BTS. In the present study, a performance evaluation experiment was conducted to investigate the pressure drop characteristics with dust loading and the particle collection efficiency of the air filter for the DAC of BTS.

• Journal of Broadcast Engineering
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• v.28 no.1
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• pp.149-152
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• 2023

In this paper, I present an approach to implement a real-time video transceiver using software-defined radio (SDR). Through this, it is expected that it will be able to lower the access threshold and provide new perspectives and insights to researchers who want to study the recently spotlighted Open Radio Access Network (O-RAN) and implement it through SDR devices and open software.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.7
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• pp.365-371
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• 2014

Chaos communication system is possible to improve the system security by using chaos signal. Further, it is possible to reduce the possibility of eavesdropping, and have strong characteristics from interference signal and jamming signal. However, BER(Bit Error Rate) performance of chaos system is worse than digital communication system. By this reason, researches in order to improve the BER performance of chaos communication system are being actively studied. In previous studies, we proposed a novel chaos map for BER performance improvement, and called it 'Boss map'. Also, we proposed a novel chaos transceiver for BER performance improvement. However, BER performance is evaluated differently according to delay time in transceiver. Therefore, in order to use Boss map effectively, we should find the optimal delay time in proposed chaos transceiver. In this paper, when Boss map is used, we evaluate BER performance of CDSK(Correlation Delay Shift Keying) system and novel chaos transceiver according to delay time. After evaluation of BER performance according to delay time, we find a delay time that is possible to have best BER performance in CDSK system and novel chaos transceiver.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.7
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• pp.26-36
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• 2014

The needs of active phased arrays antenna system is getting more increased for IMT-Advanced system efficiency. The active phased array structure consists of lots of small transceivers and radiation elements to increase system efficiency. The minimized module of high efficiency transceiver is key for system implementation. The power amplifier of transmitter decides efficiency of base-station. In this paper, we design and implement minimized module of high efficiency transceiver for IMT-Advanced active phased array system. The temperature compensation circuit of transceiver reduces gain error and the analog pre-distorter of linearizer reduces implemented size. For minimal size and high efficiency, the implented power amplifier consist of GaN MMIC Doherty structure. The size of implemented module is $40mm{\times}90mm{\times}50mm$ and output power is 47.65 dBm at LTE band 7. The efficiency of power amplifier is 40.7% efficiency and ACLR compensation of linearizer is above 12dB at operating power level, 37dBm. The noise figure of transceiver is under 1.28 dB and amplitude error and phase error on 6 bit control is 0.38 dB and 2.77 degree respectively.

• Korean Journal of Optics and Photonics
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• v.24 no.4
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• pp.196-200
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• 2013

Heretofore, it was enough that most of optical transceiver modules for automotive networks have the performance of data rate from 10 Mbps to 150 Mbps. As the required data rate in automotive infotainment systems has recently been increasing, the development of a new optical transceiver having high speed data rate over 1Gbps is now required. Therefore, we suggested a next-generation bi-directional optical transceiver module using vertical cavity surface emitting laser technology and plastic clad fiber technology, for the next-generation automotive optical network, MOST1000. We fabricated the high-speed and compact optical transceiver having 1 Gbps data rate and -22 dBm sensitivity satisfying bit error rate $10^{-12}$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.5
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• pp.646-654
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• 2020

This paper is to develop an electromagnetic wave-based sensor that can measure the spatial distribution of precipitation, and to a electromagnetic wave rain gauge (hereinafter, "EWRG") capable of simultaneously measuring rainfall, snowfall, and wind field, which are the core of heavy rain observation. Through this study, the LFM transmission and reception signals were theoretically analyzed. In addition, In order to develop a radar transceiver, LFM transceiver design and simulation were conducted. In this paper, we developed a K-BAND pulse-driven 6W SSPA(Solid State Power Amplifiers) transceiver using a small HMIC(Hybrid Microwave Integrated Circuit). It has more than 6W of output power and less than 5dB of receiving NF(Noise Figure) with short duty of 1% in high temperature environment of 65 degrees. The manufactured module emits LFM and Square Pulse waveform with the built-in waveform generator, and the receiver has more than 40dB of gain. The transceiver developed in this paper can be applied to the other small weather radar.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.111-114
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• 2004

Sensor networks are deployed with a limited energy source. Thus, energy efficient design can be challenging. This paper has been studied optimal packet length with energy efficiency for sensor networks. And using Power Management can not improve energy efficiency. Power Management is turning off transceiver when transceiver is idle statue. We show that BCH code for error control can improve energy efficiency better than Convolutional code.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2001.11a
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• pp.55-60
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• 2001

RF MEMS is an exciting emerging technology that has great potential to develop TOC (Transceiver-on-Chip). Applications of the RF MEMS to wireless communications systems are presented. The ability of the RF MEMS technology to enhance the performance and to reduce the size of passive components, in particular, switches, inductors, and tunable capacitors, is addressed. A number of potential wireless system opportunities for the TOC are awaiting the maturation of the RF MEMS technology.