• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2006.11a
• /
• pp.511-514
• /
• 2006

Material Management is one of the most important task in construction projects. More than 50% of the cost in a construction project is related to material management process. Material management method using RFID(Radio Frequency Identification) is now trying to the construction field. However, there are no enough researches on effective material management in terms of how and where RFID transponder should be installed and there are no other research that which optimization method can be used for effective installation. Therefore, this paper suggest that where and how RFID transponder can be installed on the appropriate position in construction fields using Genetic Algorithm optimization method.

• Journal of Satellite, Information and Communications
• /
• v.3 no.2
• /
• pp.43-47
• /
• 2008

COMS is the one of Korean hybrid geostationary satellite and is scheduled to be launched in 2009 by Arian V into $128^{\circ}$ E longitude. COMS is designed and manufactured for three main objectives which are Communications, Oceanographic, and Meteorological missions. It provides the weather monitoring, ocean monitoring, and Ka band satellite communication services by means of three different payloads. The Ka band communications payload was developed by Electronics and Telecommunications Research Institute (ETRI), and provides not only the digital transmission for the communication services against natural disaster but also digital transmission for the high speed multimedia services. This paper describes the overview of the electrical and mechanical design and measured performances of the Ka band communications transponder flight model (FM) for COMS.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.13 no.1
• /
• pp.74-79
• /
• 2002

The EM(Engineering Model) VCO(Voltage Controlled Oscillator) is nonlinear designed for LO(Local Oscillator) of Ka-band satellite transponder. The microstripline coupled with dielectric resonator is implemented as a high impedance inverter to improve the phase noise, and the quality factor of resonant circuit can be transferred to active device with the enhanced loaded quality factor. The developed VCO has the oscillating tuning range of 9.7965~9.8032 GHz for the control voltage range of 0~12 V. This VCO requires the DC power of 8 V and 17 mA. The phase noise characteristics are -96.51 dBc/Hz @10 KHz and -116.5 dBc/Hz @100 KHz, respectively. And, the output power of 7.33 dBm is measured.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.13 no.3
• /
• pp.405-412
• /
• 2010

The purpose of this paper is to compare complexity and to assess flexibility of competing transponder architectures for satellite communication services. For performance comparison, we consider three channelization techniques: digital down converter(DDC) based on the use of the cascaded integrator-comb(CIC) filter, tuneable pipeline frequency transform(T-PFT) based on the tree-structure(TS) and variable oversampled complex-modulated filter banks(OCM-FB) based on the polyphase FFT(P-FFT). The comparison begins by presenting a basic architecture of each channelization method and includes analytical expressions of the number of multiplications as a computational complexity perspective. The analytical results show that DDC with CIC filter requires the heavy computational burden and the perfect flexibility. T-PFT based on the TS provides the almost perfect flexibility with the low complexity over DDC with the CIC filter for a large number of sub-channels. OCM-FB based on the P-FFT shows the high flexibility and the best computational complexity performance compared with other approaches.

• Journal of Satellite, Information and Communications
• /
• v.5 no.1
• /
• pp.48-53
• /
• 2010

COMS (Communication, Ocean and Meteorological Satellite), which will be launched in June 23rd, 2010 and located on geostationary orbit at the latitude of $128.2^{\circ}E$, is a multi-function satellite for communications, ocean observation, and meteorology. In order to operate Ka-band communication payload effectively, which is one of the three payloads for COMS, the Transponder Monitoring and Control (TMC) system are necessary in ground systems. In this paper, the concepts and design of the TMC system for COMS Ka-band payload are described.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.16 no.3
• /
• pp.437-442
• /
• 2021

This study describes the design and implementation of power supply of dehop/rehop transponder of EQM(Engineering Qualification Model). We materialized the interface of the PLDIU and power supply of a satellite bus, and minimized the potential for the occurrence of such erroneous operation circuit ESD through the WCA of the space environment. We designed a reliable power supply through simulation for TID about space radiation and simulation of the vibration generated during it launched, and we confirmed that it satisfies the environmental test specification through the test space environment after production.

• Satellite Communications and Space Industry
• /
• v.2 no.1
• /
• pp.117-121
• /
• 1994

• Proceedings of the Optical Society of Korea Conference
• /
• 2006.02a
• /
• pp.365-366
• /
• 2006

• Journal of electromagnetic engineering and science
• /
• v.3 no.2
• /
• pp.140-146
• /
• 2003

In this paper, the design of a channel filter and its group-delay-and-amplitude equalizer is carried out for the Ka-band satellite transponder subsystem. The 8th order dual-mode filter is employed for high selectivity around the band-edges with an elliptic-integral function response and has an in-line configuration. The 2-pole, reflection-type, group-delay equalizer is designed and manufactured to reduce the group-delay and amplitude variation, which can be large for such a high order filter. It is noted that in both the filter and equalizer, adopting the dual-mode coupling mechanism leads to less mass and volume. Through measurement, the performance of the realized group-delay-equalized filter is shown to meet the equipment requirements and to be appropriate for the satellite input multiplexer.

• ETRI Journal
• /
• v.32 no.6
• /
• pp.969-971
• /
• 2010

Based on a de-embedding technique, a new method is proposed which is capable of evaluating chip impedance behavior over absorbed power in flip-chip bonded UHF radio frequency identification transponder ICs. For the de-embedding, four compact co-planar test fixtures, an equivalent circuit for the fixtures, and a parameter extraction procedure for the circuit are developed. The fixtures are designed such that the chip can absorb as much power as possible from a power source without radiating appreciable power. Experimental results show that the proposed modeling method is accurate and produces reliable chip impedance values related with absorbed power.