• 한국정보통신학회논문지
• /
• 제14권12호
• /
• pp.2769-2774
• /
• 2010

본 논문에서는 밀리미터파 대역의 신호 발생을 위한 헤테로다인 방식인 sideband injection locking 방법을 제안하고 실험적으로 분석하였다. 향후, 무선 이동통신, 초고속 광대역 통신망 등에 사용되어질 밀리미터파 신호는 전기적 요소의 한계로 광학적인 요소에 의해 신호를 생성하는 방법이 많이 연구되고 있으며 광학적 기술에 기초한 소자기술 등이 발전되고 있다. 따라서 본 논문에서는 향후 밀리미터파 대역에서 사용되어질 LMDS(Local Multi-point Distribution Service) 등의 시스템에서 수십기가 헤르츠급의 광원으로 응용 가능한 헤테로다인 방식을 이용한 밀리미터파 대역의 신호생성에 대한 이론적 방법 및 실험적 고찰을 통하여 검증하였다.

• 한국군사과학기술학회지
• /
• 제15권2호
• /
• pp.161-168
• /
• 2012

In this paper, we have experimentally studied on phase characteristics of airborne radome for ELINT directional finding system, because it is difficult to find theoretical solutions for phase error of the radome. Especially, we described the millimeter wave band radome that was fabricated with cyanate-ester material and its thickness was 2mm. We presented the phase error about millimeter band radome. That phase error is about 30 degrees for parallel and perpendicular polarization in the K-Ka band. That is reasonable value for the ELINT directional finding system.

• 전자통신동향분석
• /
• 제33권5호
• /
• pp.1-12
• /
• 2018

One of the most remarkable aspects of the recently completed 3GPP release-15 (5G new radio phase 1) is the fact that some millimeter-wave bands have been officially approved for 5G mobile communications. Because the demand for higher transmission capacity has only grown, other millimeter-wave or even higher-frequency terahertz-wave bands have attracted more attention over time. Based on this effort, this paper reviews and discusses the existing technologies and their trends in high-frequency circuits and systems at the millimeter and terahertz-wave bands, particularly for future mobile communications.

• IEIE Transactions on Smart Processing and Computing
• /
• 제3권4호
• /
• pp.212-220
• /
• 2014

The current cellular communications are optimized for low mobility users, meaning that their performance is degraded at high speed. Therefore, passengers in a high-speed train experience very poor radio link quality due to the significantly large number of simultaneous handovers. In addition, wireless data traffic is expanding exponentially in trains, subways and buses due to the widespread use of smartphones and mobile devices. To solve the inherent problem of cellular communication networks and meet the growing traffic demand, this paper proposes the mobile hotspot network of a millimeter-wave communication system as a mobile wireless backhaul. This paper describes the physical layer design of uplink and downlink in the proposed system, and the performances of uplink and downlink are evaluated under Rician fading channel conditions. The implemented baseband prototype of the proposed millimeter-wave communication modem is presented. This system can provide a Gbps data rate service in high-speed trains carrying hundreds of wireless Internet users.

• 전자공학회논문지
• /
• 제52권8호
• /
• pp.159-165
• /
• 2015

본 논문에서는 근접한 거리의 수동 밀리미터파 이미징 시스템을 설계하고 테스트하였다. 제안한 수동 밀리미터파 이미징 시스템은 안테나와 저잡음 증폭기, 다이오드 검출기로 구성된 94GHz 밀리미터파 이미징 센서와 2축 직교 로봇, 데이터 수집장치, 이미징 프로그램으로 구성된 제어 장치로 되어있다. 금속 공구나 IC 카드, 플라스틱 등의 물체에 대해서 영상을 측정하고, 2축 직교 로봇은 래스터 스캔을 통해서 2차원 영상을 얻을 수 있다. 60초 이내로 $20{\times}20$ 픽셀의 영상을 얻어서 출력하고, 후처리를 위해서 영상을 저장한다. 측정 영상의 해상도 개선을 위해서 여러 가지 보간법을 적용하여 성능을 확인하였다.

• 전기학회논문지
• /
• 제60권12호
• /
• pp.2386-2391
• /
• 2011

Tracking and detecting targets by the millimeter wave seeker is affected by moving of platform. In order to perform the tracking performance, stabilization of a millimeter wave seeker which consists of 2-axis gimbals was considered in this study. The feasibility of the analysis and the 2-axis gimbal servo system modeling design were verified along with some simulation results.

• 한국ITS학회 논문지
• /
• 제3권2호
• /
• pp.85-93
• /
• 2004

In this paper, microstrip stepped-impedance hairpin resonator (SIR) lowpass filter f.PF) by surface rnicromachining on GaAs substrate is sugsested. This filter has the advantages of compact side, easy fabrication, and sharp cutoff frequency response. The new SIR LPF shows the 3 dB passband of dc to 33 GHz, the insertion loss of 0.82 dB, and the return loss of better than 17 dB up to 25.57 GHz. This filter is useful for many microwave system applications.

• 한국정보통신학회논문지
• /
• 제7권6호
• /
• pp.1334-1340
• /
• 2003

본 논문에서는 밀리미터파 대역의 신호 발생을 위한 헤테로다인 방식을 제안하였다. 향후, 무선 이동통신, 광대역 통신망에 사용되어질 밀리미터파 신호는 전기적 요소의 한계로 광학적인 요소에 의해 신호를 생성하는 방법을 연구 중에 있다. 광학적인 요소에 의한 여러 가지의 연구들이 광검출기의 기능, 밀리미터파 대역의 발진기의 개발 등이 이루어지고 있으며, 무선 통신망에 적용하기 위한 소자기술 등이 발전되고 있다. 본 논문에서는 향후 밀리미터파 대역에서 사용되어질 LMDS(Local Multi-point Distribution Service) 등의 시스템에서 광원으로 응용 가능한 방법을 제안하였다.

• 한국전자파학회:학술대회논문집
• /
• 한국전자파학회 2000년도 종합학술발표회 논문집 Vol.10 No.1
• /
• pp.197-201
• /
• 2000

In this paper, a MMIC(Monolithic Microwave Integrated Circuit) broadband drive amplifier for wireless communication system has designed using active feedback method. The MMIC brodband amplifier was designed using 0.5$\mu\textrm{m}$ MESFET of ETRI library. Simulation results show that gain is 22 dB, and gain flatness ${\pm}$1 dB. Maximum output power 15 dBm and noise figure 2.5 dB in bandwidth 500 MHz ～3.0 GHz. The MMIC Broadband amplifer's chip area is 14mm${\times}$1.4mm.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2001년도 하계종합학술대회 논문집(1)
• /
• pp.53-56
• /
• 2001

This paper has been developed a millimeter-wave radar to prevent car collision. This system needs to progress the problem as follows; (1) Increase of traffic accidents causing damage and injuries due to the increased number of motor vehicles and long distance driving, (2) Need for a device to help drivers who are in trouble due to bad weather conditions. (3) Need for a millimeter-wave radar as obstacles which need to be detected are small. This system is composited with some major technologies, Narrow beams to recognize obstacles or other objects, One-side circuit technology to prevent interference between electric waves, and Parts designed for radar products which are able to transmit millimeter - waves. The system has a various a application Field, Car distance auto-control system, prevent bump collision due to unexpected stoppage of the front car or careless driving, obstacle warning system, Car following system, and industrial and military purposes system. We have a looking forward to propose to develop field tests under various road conditions and hybrid car sensor by combining with other sensors