• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.4A
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• pp.415-422
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• 2004

DSRC provides high speed radio link between Road Side Equipment and On-Board Equipment within the narrow communication area. In this paper, a 5.8 GHz down-conversion mixer for DSRC communication system was designed and fabricated using 0.8 ${\mu}{\textrm}{m}$ SiGe HBT process technology and RF/LO matching circuits, RF/LO input balun circuits, and If output balun circuit were all integrated on chip. The chip size of fabricated mixer was 1.9 mm${\times}$1.3 mm and the measured performance was 7.5 ㏈ conversion gain, －2.5 ㏈m input IP3, 46 ㏈ LO to RF isolation, 56 ㏈ LO to IF isolation, current consumption of 21 mA for 3.0 V supply voltage.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.3
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• pp.69-79
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• 2001

비동기 및 차세대 이동통신 시스템의 진화 과정 상에서 RF관련 규격들의 변화에 대해 알아보았고, 비동기 시스템의 RF부를 제작하는데 사용하게 될 RF 부품 기술 동향을 단말기와 기지국의 경우로 나 누어 분석하였다. 또한 차세대인 4세대 시스템 RF 부의 진화 전망에 대해 간단히 알아보았다. 시스템 이 진화할수록, 요구되는 데이터 처리 능력으로 인 해 채널 대역폭은 점점 넓어지고, 기존 시스템과의 상호 간섭 방지를 위해 일반적인 RF 관련 규격 중 방사 규격과 요구되는 선형성이 엄격해진다. 앞으로 의 RF 부품의 기술적 진화는 직접 변환 방식의 부 품 개발로 단말기의 소형화, 저가격화를 이를 것이 고, 동작 주파수 영역을 0.8~5 GHz대로 하기 위한 광대역화, 선형화가 요구될 것이다. 또한 4 세대 시스템에서는 기존의 주파수 이용 개념과 무선 전송 기술에 변화를 주게 될 SDR 기반의 다중모드/복합 다중 접속 기술을 적용하게 될 것으로 예상된다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.288-292
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• 2002

We propose the new type of on-chip ESD protection method for RF applications. By using the properties of RF circuits, we can use the short-circuited stub as ESD protection device in front of the DC blocking capacitor Specially, we can use short-circuited stub as the portion of the matching circuit so to reduce the and various parameters of the transmission line. This new type ESD protection method is very different from the conventional ESD protection method. With the new type ESD protection method, we remove the parasitic capacitance of ESD protection device which degrade the performance of core circuit.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.207-207
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• 2004

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.886-887
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• 2011

To obtain a transparent electrode, AZO thin film was deposited on SiOC film with various flow rates by rf magnetron sputtering system. SiOC film was deposited with various DMDMOS/O2 flow rate ratio by CVD, The optical electrical properties of the SiOC film and SiOC/AZO were analyzed by the uv visible spectrometer and 4 point prove system. The reflectance of SiOC/AZO film was changed in compared with that of SiOC film. The resistance was decreased with low RF power because of increasing the concentration of carriers.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.997-1000
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• 2006

In this paper, we have used the 900Mha RF band and produced the transmitter-receivers to measure the distance of moving range of a crane. We selected the analog signal of 450Khz middle frequency band of the RF Baseset module, and the property data of phase response is analysed to estimate the range distance. We have earned the good results from the experiment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.461-462
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• 2016

IPS 측위는 GPS음영 지역인 실내의 특정 위치 정보를 판단하는 시스템으로 현재 위치에서 발생되는 신호 정보를 수집하는 시스템과 이 신호들로 구성된 실내 측위 지도, 측위 위치를 결정하기 위한 알고리즘 등에 따라 여러 종류로 나누어진다. 대표적인 IPS로 2.4Ghz, 5.0GHz 대역의 무선 신호(WiFi, BLE, Sensor Network, etc)를 활용하는 RF신호 기반 WPS 등이 있다. RF 신호를 기반으로 하는 실내 측위는 발생 기기의 고장, 장애물 발생, 채널 간섭 현상 등으로 인해 측위 시점 수집된 신호와 구축된 지도의 신호 정보가 달라 측위 정확도가 낮아지는 경우가 발생한다. 본 논문에서는 앞서 언급한 문제점을 해결하기 위해 기존 RF 환경을 사용하는 IPS 방안에 대하여 분석한다. 또한 RF 이외의 실내 측위 기술들에 대해서도 설명하고 측위 정확도를 위해 단일 측위 방식이 아닌 복합 측위 방식에 대한 설계를 제안한다.

• Electronics and Telecommunications Trends
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• v.39 no.1
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• pp.25-35
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• 2024

Wireless communication, including mobile networks and local area networks, has become an essential service in the society. Wireless communication is evolving to include sensing services, as demonstrated by the increasing attention in organizations and standards such as 3GPP and IEEE 802.11. This survey presents technology trends in the integration of sensing and communication. The standardization status along with use cases provided by standards are explained. In addition, core and supporting technologies such as channel modeling, waveform design, and artificial intelligence are analyzed.

• Journal of Satellite, Information and Communications
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• v.1 no.2
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• pp.45-50
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• 2006

A satellite and ground stations which are developed in a program are tested whether the interface between the satellite and ground is well established before satellite operations. These compatibility tests are performed when the satellite is connected with the ground stations after all satellite and ground stations requirements are verified. The content of the RF compatibility test is to check whether the interface requirements which are described on the Interface Control Document are well developed. During the early operation phase and tentative contingency operations of the satellite, KARI ground station uses other oversea ground stations which are located worldwide according to contract between the KARI and the contractor. Since oversea ground stations were not developed for the designated space program, system integrator should check whether the oversea ground stations are satisfied with interface requirements. Using the RF suitcase, RF interface and the content of RF communication can directly be verified during RF compatibility test on oversea ground station without KARI ground station's support. The RF compatibility test using RF suitcase was performed oversea ground stations as well as KARI ground station located on Korea. The content of RF compatibility test was standardized in order to be used at any oversea ground stations, especially fitted for the operations concept of launch and early operations phase. The test content would be RF characteristics, protocol, command loop test, telemetry loop test, and ground station interface test.

• Electronics and Telecommunications Trends
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• v.36 no.3
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• pp.53-64
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• 2021

As the 5G service market is expected to grow rapidly, the development of high-power, high-efficiency power amplifiers for the 5G communication infrastructure is indispensable. Gallium nitride (GaN) is attracting great interest as a key device in power devices and integrated circuits due to its wide bandgap, high carrier concentration, high electron mobility, and high-power saturation characteristics. In this study, we investigate the technology trends of Ka-band GaN radio frequency (RF) power devices and integrated circuits for operation in the millimeter-wave band of recent 5G mobile communication services. We review the characteristics of GaN RF high electron mobility transistor (HEMT) devices to implement power amplifiers operating at frequencies around 28 GHz and compare the technology of foreign companies with the device characteristics currently developed by the Electronics and Telecommunication Research Institute (ETRI). In addition, the characteristics of Ka-band GaN monolithic microwave integrated circuit (MMIC) power amplifiers manufactured using various GaN HEMT device technologies are reviewed by comparing characteristics such as frequency band, output power, and output power density of integrated circuits. In addition, by comparing the performance of the power amplifier developed by ETRI, the current status and future direction of domestic GaN power devices and integrated circuit technology will be discussed.