Abstract: Disclosed is a satellite performance monitoring system. The satellite performance monitoring system may include a satellite communication controlling apparatus that is installed outdoors to transmit a test signal for measuring a performance of a satellite transponder to the satellite transponder and thereby receive a test response signal from the satellite transponder, and to transmit a reference signal to the satellite transponder and thereby receive a reference response signal from the satellite transponder; and a satellite performance monitoring apparatus that is installed indoors to generate the test signal and the reference signal, to generate a frequency response characteristic with respect to the satellite transponder using the test response signal, to compute a signal change amount occurring due to a weather condition using the reference signal and the reference response signal, and to apply the computed signal change amount to the frequency response characteristic.

Abstract: Provided are a beacon signal generating apparatus and a phase synchronizing apparatus using the same for establishing a phase synchronization while tracking a phase variation of a Timing Source Oscillator (TSO) of a satellite using a simpler scheme at an earth station, in making a phase synchronization between a clock signal of an On board Switch (OBS) embedded in the satellite and that of the earth station in a Satellite Switched Time Division Multiple Access (SS-TDMA) satellite communication system. The inventive beacon signal generating apparatus embedded in a satellite comprises a frequency oscillator for creating a TSO frequency, a beacon signal generator for multiplying the TSO frequency to be matched with a beacon signal frequency to generate a beacon signal synchronized with the TSO frequency, and a transmitter for transmitting the beacon signal to each of earth stations to recovery a frequency synchronized with the TSO frequency.

Abstract: A fault management system using a satellite telemetering technology and a method thereof are provided. The fault management system includes: a telemetering sensing unit for collecting telemetering data from target apparatuses, which are installed at a remote location and an unattended location and managed through a satellite, in real time and sensing whether the target apparatuses are malfunctioned or not based on the collected telemetering data; a controlling unit for determining whether the target apparatuses are malfunctioned or not by comparing the telemetering data with unique performance request values for normally driving the target apparatuses, analyzing causes of malfunctions, and storing malfunction data into a malfunction data storing unit; a malfunction data analysis unit for managing the malfunction data stored in the malfunction data storing unit and analyzing the malfunction data; and a display unit for outputting the result of analyzing the malfunction data on a display device.

Abstract: Provided is a voltage controlled oscillator having a new type of a resonator and a negative resistance part capable of finely tuning negative resistance. Thus, the voltage controlled oscillator has an excellent quality factor characteristic and can finely tune the negative resistance even after its fabrication is completed. The voltage controlled oscillator having an active element includes: a resonating unit for generating an oscillation frequency according to a resonance capacitance; a frequency tuning unit, connected to a source terminal of the active element, for tuning the oscillation frequency; and a negative resistance adjusting unit, connected to the frequency tuning unit, for generating a negative resistance to adjust the oscillation frequency, the negative resistance adjusting unit including a varactor diode for finely adjusting the negative resistance.

Abstract: Provided are a beacon signal generating apparatus and a phase synchronizing apparatus using the same for establishing a phase synchronization while tracking a phase variation of a Timing Source Oscillator (TSO) of a satellite using a simpler scheme at an earth station, in making a phase synchronization between a clock signal of an On board Switch (OBS) embedded in the satellite and that of the earth station in a Satellite Switched Time Division Multiple Access (SS-TDMA) satellite communication system. The inventive beacon signal generating apparatus embedded in a satellite comprises a frequency oscillator for creating a TSO frequency, a beacon signal generator for multiplying the TSO frequency to be matched with a beacon signal frequency to generate a beacon signal synchronized with the TSO frequency, and a transmitter for transmitting the beacon signal to each of earth stations to recovery a frequency synchronized with the TSO frequency.

Abstract: An apparatus for transmitting/receiving destination wake-up information through communication satellite network is disclosed. The apparatus includes: an input/output unit for receiving ticketing data from an external device, transmitting the ticketing data to a storing unit and outputting the ticketing data to a baseband processing unit by reading from the storing unit according to transmission conditions; a storing unit for storing the ticketing data based on a control of the controlling unit; a baseband processing unit for converting the ticketing data into a baseband signal; and a wireless transceiving unit for converting the baseband signal into a wireless signal and emitting the wireless signal through a satellite antenna.

Abstract: A vehicle position information transmitter via satellite, a method thereof, a vehicle position tracking system using the same and a method thereof are provided. The transmitter transmits vehicle position information and vehicle ID to the vehicle position information management center through the vehicle position information relay satellite if a satellite network communication state is good as the result of comparing a satellite signal intensity with a mobile communication signal intensity, or transmits vehicle position information and vehicle ID to the vehicle position information management center through the terrestrial network if a terrestrial network communication state is good as the result of comparing a satellite signal intensity with a mobile communication signal intensity.

Abstract: Provided are an apparatus for controlling a switch of a satellite transponder for multibeam communication, and a method thereof. The apparatus and method can increase output efficiency of communicated satellite electric wave signals and reuse frequencies in one-to-one earth station communication or a one-to-multi earth station communication.

Abstract: Disclosed is a command planning apparatus of a low-earth orbit satellite, and a low-earth orbit satellite control system including the same. The present invention automates the process of executing the command plan for converting the satellite task schedule planned on the ground into telecommands available by the satellite in the low-earth orbit satellite control system, and automatically selects a data set established by the parameters related to the execution task of the satellite according to the mapping rule.

Abstract: Provided is a voltage controlled oscillator having a new type of a resonator and a negative resistance part capable of finely tuning negative resistance. Thus, the voltage controlled oscillator has an excellent quality factor characteristic and can finely tune the negative resistance even after its fabrication is completed. The voltage controlled oscillator having an active element includes: a resonating unit for generating an oscillation frequency according to a resonance capacitance; a frequency tuning unit, connected to a source terminal of the active element, for tuning the oscillation frequency; and a negative resistance adjusting unit, connected to the frequency tuning unit, for generating a negative resistance to adjust the oscillation frequency, the negative resistance adjusting unit including a varactor diode for finely adjusting the negative resistance.

Abstract: Disclosed is an adaptive downlink packet transmission method for a multicarrier Code Division Multiple Access (MC-CDMA) system. The method can allocate radio resources efficiently according to the variations of channel conditions for each user terminal, allocate transmission power appropriately according to the interference from the same cell, and minimize interference to adjacent cells.

Abstract: Provided are an apparatus for controlling a switch of a satellite transponder for multibeam communication, and a method thereof. The apparatus and method can increase output efficiency of communicated satellite electric wave signals and reuse frequencies in one-to-one earth station communication or a one-to-multi earth station communication.

Abstract: A vehicle position information transmitter via satellite, a method thereof, a vehicle position tracking system using the same and a method thereof are provided. The transmitter transmits vehicle position information and vehicle ID to the vehicle position information management center through the vehicle position information relay satellite if a satellite network communication state is good as the result of comparing a satellite signal intensity with a mobile communication signal intensity, or transmits vehicle position information and vehicle ID to the vehicle position information management center through the terrestrial network if a terrestrial network communication state is good as the result of comparing a satellite signal intensity with a mobile communication signal intensity.

Abstract: A satellite simulation model system based on an interface standard model is disclosed. The system includes a satellite subsystem standard model for simulating operations of physical satellite subsystems; a flight software module for generating a control signal changing operation state of the satellite subsystem standard model; an interface standard model for converting data transmitted from the satellite subsystem standard model and the flight software module into data to receiving components and transmitting the converted data to the receiving components; and a model managing unit for generating the satellite subsystem standard model and the interface standard model as independent component objects and controlling each component object to perform satellite simulation.

Abstract: A fault management system using a satellite telemetering technology and a method thereof are provided. The fault management system includes: a telemetering sensing unit for collecting telemetering data from target apparatuses, which are installed at a remote location and an unattended location and managed through a satellite, in real time and sensing whether the target apparatuses are malfunctioned or not based on the collected telemetering data; a controlling unit for determining whether the target apparatuses are malfunctioned or not by comparing the telemetering data with unique performance request values for normally driving the target apparatuses, analyzing causes of malfunctions, and storing malfunction data into a malfunction data storing unit; a malfunction data analysis unit for managing the malfunction data stored in the malfunction data storing unit and analyzing the malfunction data; and a display unit for outputting the result of analyzing the malfunction data on a display device.

Abstract: An apparatus for repeating a signal from a satellite using a microstrip patch array antenna is disclosed. The apparatus includes: a receiving unit for receiving the signal and amplifying the receiving signal; a radiating unit for radiating the amplified signal to the shadow area; and a feeding unit for feeding the amplified signal to the radiating unit.

Abstract: A fast LUT predistortion apparatus and method for compensating nonlinear distortion of the high power amplifier HPA is disclosed. The apparatus includes a predistortion unit for predistorting an input complex digital signal based on a look up table LUT implementation and outputting a predistorted complex signal; and a power amplifier for amplifying the predistorted signal and outputting an amplified complex signal.

Abstract: An apparatus and method for detecting a defect on a ground layer of microstrip by using scattering parameters is disclosed. The apparatus includes: a providing unit for providing a signal to the microstrip by changing a frequency of the signal in a predetermined range of frequencies; a detecting unit for detecting scattering parameters of an output signal from the microstrip in response to the frequency of the signal; and an analyzing unit for analyzing the interface based on the scattering parameters.

Abstract: Provided is an antenna aligning apparatus for near-field measurement, which can perform alignment between a measurement target antenna and a probe antenna precisely by using an antenna pattern and detecting coordinates of the least error. The antenna aligning apparatus includes: a receiving antenna, a signal dividing means, a vertical polarization port, a horizontal polarization port, a first amplitude/phase detector, a second amplitude/phase detector, a coordinate determining means for, and a position adjuster.

Abstract: Disclosed is a command planning apparatus of a low-earth orbit satellite, and a low-earth orbit satellite control system including the same. The present invention automates the process of executing the command plan for converting the satellite task schedule planned on the ground into telecommands available by the satellite in the low-earth orbit satellite control system, and automatically selects a data set established by the parameters related to the execution task of the satellite according to the mapping rule.