• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.525-528
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• 2003

This paper describes the effective and rigorous analytic method of multipath effect which results from insufficient isolation characteristics between adjacent channels in communication payload system. It is very important to analyze the multipath effect for verifying the performance of transponder subsystem that especially is consist of multi channels. Finally the multipath effect are analyzed by calculating the GR and GDR for two adjacent channels of Ku-band transponder subsystem on the Communication & Broadcasting Satellite(CBS).

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.363-366
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• 2002

In this paper, we present a Ku-band OMT(orthomode transducer) structure employing a simple waveguide transition withou a septum. Various aspects of the OMT design are discussed. The design is carried out using a commercial software HFSSe The designed OMT shows good characteristics over 12.5114.25 CHz frequency bands.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.215-218
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• 2002

Design methods are presented for a broadband corrugated horn antenna operating X/Ku band (7.25-14.5 CHz). The corrugated horn consists of a circular waveguide taper, a mode converter, a waveguide-to-horn transition, and a hem section. Methods of design are presented for each section. The designed antenna shows excellent characteristics over the entire operating frequency range.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.1
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• pp.83-89
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• 2010

In this paper, we propose a new varactor coupled line structure and design the VCO using the proposed structure. The proposed coupled line structure removes the reflected signals from the varactor diode using an added $\lambda$/4 transmission line. The frequency synthesizers are designed using the PLL technique at Ku-band. The synthesizer using the proposed coupled structure has 38 MHz frequency tuning range and -97 dBc/Hz phase noise characteristic at 100 KHz offset frequency. The measured results show improved tuning range as well as the improved phase noise characteristics compared to the conventional designs.

• Information and Communications Magazine
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• v.12 no.6
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• pp.65-73
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• 1995

위성통신용 궤도와 주파수 자원은 매우 한정적이며 최근에 정지궤도 위성과 저궤도 위성을 이용한 다양하나 형태의 서비스에 대한 수요가 급증하고 있으므로 한정된 주파수 자원에 대한 효율적인 활용기술과 새로운 주파수자원 및 서비스 개발이 필요하다. 북미, 유럽, 일본은 1970년도 중반기부터 C-band를 이용하는 위성통신의 연구를 시작으로, 최근에는 L-band, Ku-band, Ka-band를 이용하는 위성통신에서 효율적으로 전력 및 주파수를 활용하는 방안에 대한 연구를 활발하게 진행하고 있다. 국내는 1980년도 하반기부터 Ku-band를 이용하는 위성통신에 대한 연구가 시작되었으나 아직도 장기적이고 구체적인 연구개발 계획이 미비한 상황이며 Ka-band 정지궤도와 L-band 저궤도 위성통신 기술의 연구개발은 아직 초보적인 단계이다. 따라서 본 논문에서는 위성통신용 주파수의 국제적인 이용현황과 추세를 분석하여 향후 국내에서 정지궤도 및 저궤도 위성의 궤도와 주파수 확보 및 활용에 참고가 되도록 한다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.2
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• pp.168-177
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• 2003

The performance sensitivity analysis due to manufacturing/alignment errors is performed for the Ku-band offset parabola antenna of the domestic Communications and Broadcasting Satellite. The performance variations due to reflector random surface error, which inevitably happens during reflector manufacturing, are statistically analyzed using RMS error and correlation interval. The impact on the antenna performance of the fred hem's position and angular errors is investigated, and the sensitive directions are identified. When the target tolerances are applied, the performance degradations are found to be within the loss budget or corresponding performance margins.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.7
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• pp.500-507
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• 2018

A three-channel radio frequency (RF) monopulse receiver using a data signal with a maximum transmission rate of 274 Mbps was designed. A monopulse receiver using a broadband communication signal was designed to operate in the Ku band, and it consists of a down-conversion module and a signal-processing module. To satisfy the performance of the proposed RF monopulse receiver, a signal-processing function less than the reception sensitivity for each transmission rate according to the adaptive transmission rate is required. To minimize signal reception and mutual frequency interference of various bandwidths, two RF filters were applied. To verify the satisfaction of system requirements, an AWR Corp. simulation tool was used.

• Journal of Satellite, Information and Communications
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• v.10 no.3
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• pp.137-142
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• 2015

This paper analyzed the background and status of studies for WRC-15 agenda item which considers additional frequency allocations to the fixed-satellite service in Ku-band and considered national future countermeasures. Satellite frequency can be acquired through compliance with the Radio Regulations for international registration and it has been recognized as the limited natural resource, and which leads to intensifying the competition among countries for the preoccupancy of it. Under the circumstances, WRC-15 is going to consider additional allocations to the fixed-satellite service in Ku-band and it is necessary to cope with the situation taking into account adequate protection of the existing services and future plan of frequency usage by the fixed-satellite service.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.2 no.2 s.3
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• pp.97-101
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• 2003

A MMIC (monolithic microwave integrated circuit) mixer chip using the Schottky diode of an InGahs/CaAs p-HEMT process has been developed for the receiver down converter of Ku-band. A different approach to the MMIC mixer structure is applied for reducing the chip size by the exchange of ports between If and LO. This MMIC covers with RF (14.0 - 14.5 GHz) and If (12.252 - 12.752 GHz). According to the on-wafer measurement, the miniature (3.3X3.0 m) MMIC mixer demonstrates conversion loss below 9.8 dB, RF-to-IF isolation above 23 dB, LO-to-IF isolation above 38 dB, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.11
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• pp.978-984
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• 2015

In this paper, we designed a RF transceiver operating up to 200 km operating range and 45 Mbps data rate. The RF transceiver operates in Ku band and composed of up/down converter, high power amplifier, front-end elements. To satisfy the operating range of RF transceiver, 10W power amplifier was required and realized by using GaN power amplifier. Moreover, to mitigate mutual interference for different bandwidth signals due to the adaptive transmission speed control function, SAW filter bank structure was used. To verify system requirement satisfaction AWR simulation tool was used.