• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.5
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• pp.417-424
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• 2021

The S-band telemetry and telecommand formats for geostationary orbit satellites should have sufficient reliability, since they transmit massive satellite health data and receive the mission commands in the 36,000km of the geostationary orbit. Also, they have to efficiently manage the large quantity of satellite health data under the limited data transmission rate. Cheollian-2A and 2B satellites were developed by Korea Aerospace Research Institute and launched at 2018 and 2020, respectively. Their missions are to conduct continuously the mission of Cheollian-1, which was the first geostationary orbit satellite of Korea. Therefore, the fundamental S-band data format design for Cheollian-2A and 2B should meet the requirements of Cheollian-1. Meanwhile the latest remote data processing techniques for these newest geostationary orbit satellites should be implemented. In this paper, the advanced S-band space data formats and management methods are proposed for more efficient data transmission, reception and operation with the limited data rate of the geostationary orbit satellites. The implemented results in the flight software of Cheollian-2A and 2B are described in detail.

• Journal of electromagnetic engineering and science
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• v.9 no.4
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• pp.223-228
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• 2009

In this paper, a quadrafilar antenna is designed to have a lower profile as an essential part of the size reduction technique and lower back radiation(i.e. higher forward radiation) for the S-band telemetry/telecommand(TM/TC) function of a communication satellite. Particularly, to meet the challenging requirements on the higher isolation between the TM/TC antennas and simultaneously a smaller size, the lowest back radiation and lowest cross-polarization, the optimal physical dimensions of the quadrafilar antenna are found by using the Genetic Algorithm(GA). To prove the validity of the proposed antenna design, its 3D electromagnetic analysis and measured results are compared, showing good agreement.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.12
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• pp.2468-2473
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• 2009

In this paper, a quadrafilar antenna is designed to have a lower profile as an essential part of the size reduction technique and lower backradiation(namely, higher forward radiation) for the S-band telemetry/telecommand(TM/TC) function of a communication satellite. Particularly, to meet the challenging requirements on the higher isolation between the TM/TC antennas and simultaneously a smaller size, the lowest backradiation and lowest cross-polarization, the optimal physical dimensions of the quadrafilar antenna are found by using the Genetic Algorithm(GA). To prove the validity of the proposed antenna design, its 3D electromagnetic analysis and measured results are compared to show good agreement. Using this antenna as the elements, an array antenna is made to have directivity.