• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.654-657
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• 2002

This paper introduces the design and implementation of 40-㎓-band low noise amplifier (LNA) with ultra low gain flatness for wide-band wireless multimedia and satellite communication systems. The 40-㎓-band 4-stage LNA MMIC (Monolithic Microwave Integrated Circuit) demonstrates a small signal gain of more than 20 ㏈, an input return loss of 10.3 ㏈, and an output return loss of 16.3 ㏈ for 37$\square$42 ㎓. The gain flatness of the 40-㎓-band 4-stage LNA MMIC was 0.1 ㏈ for 37$\square$42 ㎓. The noise figure of the 40 ㎓-band LNA was simulated to be less than 2.7 dB for 37~42 ㎓. The chip size of the 4-stage LNA MMIC was 3.7${\times}$1.7 $\textrm{mm}^2$.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.3
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• pp.33-42
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• 2002

응용분야가 다양하고 고속 전송 및 노이즈 레벨의 주파수 대역에서 통신을 할 수 있는 UWB(Ultra Wide Band) 기술에 대한 관심이 증폭되고 있다. 울트라 쇼트 펄스파(ultra short pulse)에 정보를 실려 송수신하는 UWB 기술을 근거리 고속 통신이나 휴대용 단말기에 응용하고 저가격의 제품제작을 위하여 저전력 IC 개발은 핵심요소이다. 본 글에서는 UWB IC의 회로 구성 및 동작과 IC 개발업체의 현황을 논한다.

• Journal of the Semiconductor & Display Technology
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• v.9 no.2
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• pp.7-10
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• 2010

In this paper, we design a modem SoC (System on Chip) for low power consumption and high speed wireless communications. Among various schemes of high speed communications, an MB-OFDM (Multi Band-Orthogonal Frequency Division Multiplexing) UWB (Ultra-Wide-Band) chip is designed. The MB-OFDM uses wide-band frequency to provide high speed data rate. Additionally, the system imposes no interference to other services. The 90nm CMOS (Complementary Metal-Oxide Semiconductor) technology is used for the SoC design. Especially, power management mode is implemented to reduce the power consumption.

• Journal of Advanced Navigation Technology
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• v.25 no.5
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• pp.357-362
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• 2021

UWB(ultra wide band) communication systems employ short pulses to transmit information which spreads the signal energy over a very wide frequency spectrum. Received signal-to-noise power ratio of UWB signals is an important factor in determining the accuracy of a positioning system. As the signal to noise power ratio gets higher, positioning errors decrease since noise becomes less effective. Calculation of signal to noise power ratio as a function of communication distance provides important guidelines for the system design. And the performance of a positioning system also depends heavily on the channel model. As a result of the analysis, it was found that the performance of the received signal to noise power ratio according to the communication distance was better in the LOS channel environment than in the Non LOS(line of sight) channel environment. And as the symbol interval of the preamble signal increases at a specific communication distance, the channel capacity of the UWB system increases.

• Journal of Communications and Networks
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• v.5 no.4
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• pp.285-289
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• 2003

• 한국ITS학회:학술대회논문집
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• 2003.11a
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• pp.188-191
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• 2003

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.07a
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• pp.86-86
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• 2004

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.07a
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• pp.436-436
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• 2004

• Journal of the Optical Society of Korea
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• v.17 no.1
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• pp.109-109
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• 2013

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.8A
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• pp.836-846
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• 2007

Wireless Communication is playing a key role in implementing the ubiquitous society. However, due to the increasing wireless and mobile devices occupying the spectrum, the frequency resources are believed to become more and more limited. In order to deal with the problem, coexistence is considered to be a effective method to improve the efficiency of spectrum utilization between several different systems. Here, we utilize the UWB system to realize the coexistence, because it is an ultra wide band system which can co-exist with other narrow band systems. On the other hand, Cognitive Radio technology is an intelligent technology which can sense the spectrum environment and adaptively adjust the parameters for wireless transmission. In this paper, by using Cognitive UWB, the spectrum efficiency of the transmission channels is largely improved; Furthermore, the interference to other systems can be effectively avoided.