• Journal of the Korea Society for Simulation
• /
• v.27 no.2
• /
• pp.25-33
• /
• 2018

When developing military equipment, it should be designed considering the temperature condition so that the operator can operate in a stable environment. The shelter for storing various military equipments is operated in various environments. The storage temperature and operating requirements of the test equipment and repair accessories shall be $-32^{\circ}C$ to $50^{\circ}C$ and the inside of the shelter shall be designed to meet the storage temperature and operating requirements. In this study, thermal analysis of a 2.5 ton military shelter operating under high temperature and solar heat conditions is performed considering MIL-STD-810G. The thermal analysis was applied by using the concept of heat resistance and heat circuit, and the solar thermal test was performed on the actually manufactured military shelter in order to verify the analysis results.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.42 no.1
• /
• pp.90-97
• /
• 2014

In this paper, we have designed the antenna for Korea SAT-5 Satellite Communication which can use Ka band in the earth station. The antenna structure consist of the the dual-offset gregorian reflector that has high gain and efficiency, the corrugated horn that has symmetric radiation patterns and low side lobe levels, the iris polarizer that make circular polarization and the OrthoMode Transducer that separate transmitting and receiving signals. The designed antenna gain is more than 45.7dBi in Tx-band which use LHCP and 42.0dBi in Rx-band which use RHCP. The co-polarized and cross-polarized radiation pattern comply with ITU-R S.580-6 and S.731-1 that are recommended by International Telecommunication Union in the geostationary satellite. The Axial ratio is less than 1.0dB in Tx-band and 1.5dB in Rx-band that meet MIL-STD-188-164A.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.14 no.6
• /
• pp.440-448
• /
• 2009

Facility power-line electromagnetic interference (EMI) filters are used to provide radio frequency(RF) isolation between dedicated power distribution services and noise sensitive local power distribution systems. This type of EMI filters generally needs a high current capacity and, in some special applications, a high insertion loss of a minimum 100dB from 14kHz through 10GHz per MIL-STD 220 is required. This paper deals with an analysis and design of a wideband facility power-line EMI filter with the above requirements. The characteristics of the inductor and capacitor at high frequencies are investigated. The characteristics and design method of the facility EMI filter with a high order LC network are also presented. The prototype filter is finally implemented and its performance is verified from the experimental results.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.26 no.11
• /
• pp.992-998
• /
• 2015

In case of UHF Band Transceiver for Army Aircraft, it shall follow MIL-STD-461F Figure CE101-4 most key design points for this equipment were to minize the current consumption and frequency interference since it will be integrated on aircraft. However, after design, abnomal signal(over 100 dBuA) was occured from 30 Hz to 1 kHz on CE101 test. Occured abnomal signal was measured as 50 Hz signal which was tansceiver $T_{DD}$ signal with the output power of 10 W and 20 ms periods. To meet the specification, current variation needed to be minized. Thus, $I_{dq}$ and $I_d$ of power amplifier were modified almost equally through test result and finally, the equipment was designed and developed with no difference of current consumption and frequency interference from the previous design goal.

• Journal of Advanced Navigation Technology
• /
• v.22 no.5
• /
• pp.351-358
• /
• 2018

In this study, we propose a method of suppressing the leakage noise signal of motor assembly through the test. The motor assembly is mounted on outside of the aircraft to rotate an antenna and must satisfy RE102 requirement on MIL-STD-461F in terms of electromagnetic interference. It is confirmed by RE102 test result hat the leakage noise signal of the equipment occurs due to external influx through the power and control cable and rotation of the motor. And it is ascertained that the part where internal/external physical shielding is difficult to rotate is the leakage path. To reduce the leakage noise signal, the electrical ground reinforcement and the electric shielding structure considering the operation of the equipment is applied and it is verified that the requirement is satisfied. Finally, we verified that required specification are met by applying circular corrugated choke with interlocking shapes and conductive grease to the noise leakage path.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.30 no.5
• /
• pp.127-133
• /
• 2002

The general requirements to achieve the structural integrity of the airframe are described in the military specification, MIL-STD-1530A. One of these requirements is the durability and damage tolerance of the airframe, which should be shown through the analysis and test based on the related specifications. This paper introduces the full scale durability test to evaluate the structural safety and durability of the basic trainer, KT-1. The test was performed according to the procedure in the military specification. The flight by flight load spectrum was developed by KT-1 fatigue load criteria and used for the durability test. The durability test had been performed for 4 service lives and was completed successfully. Therefore, it was shown that KT-1 airframe satisfied the durability requirements.

• Journal of Satellite, Information and Communications
• /
• v.8 no.1
• /
• pp.54-60
• /
• 2013

The need for high performance of on-board computer (OBC) is essential due to the growing requirements and diversified missions, and so OBC has been developed on the basis of the standard design and reconfigurable modularization in order to improve the utilization of OBC for different missions. The processor in OBC of next generation satellite which is currently developed by KARI is adopted the LEON2-FT/AT697F processor based SPARC v8 as main processor and controls various devices such as SpaceWire, MIL-STD-1553B and CAN through PCI on the standardized communication chips. This paper presents the architecture and design of system software for LEON2-FT processor based on PCI, and development of PCI software component. Also it describes the porting of VxWorks 6.5 for LEON2-FT and the test under the simulation environment for LEON2-FT and PCI with communication chips.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.27 no.12
• /
• pp.1097-1104
• /
• 2016

The infrared camera is difficult to satisfy the RE-102 specification of Mil-Std-461. Especially, in the case of UAV electronics, shielded cable is not used, so it is difficult to meet the electromagnetic compatibility standard. In the RE-102 test of the IR camera for UAV, radiated noise exceeding 30 dBuV/m was observed in the range of 50 MHz to 200 MHz. As a result of pcb em scan, peak noise which caused by the harmonic frequency of the digital control signal clock was observed. Radiated noise was reduced by up to 22.9 dBuV/m by applying the spread spectrum clock generator(SSCG) with 3 % down spreading method to the camera control clock.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.44 no.9
• /
• pp.769-774
• /
• 2016

Epoxy polymer exposed to solar radiation on long-term is required to a long-term environmental test in order to ensure the reliability of operation performance. In this paper, the solar aging experiment is performed for 7, 14, 28, 56, and 84 cycles, using solar simulator designed according to MIL-STD-810. After the aging experiment, measuring RGB values and using the CIE1976 color space, each RGB decreasing rates and total color shift are calculated. In addition, using a universal testing machine, mechnical properties according to ASTM-D638 are measured. As a result, by increasing solar aging period, total color shift is increased, and the tensile strength and elongation are decreased, but the elastic modulus and the poisson's ratio are slightly changed.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.40 no.12
• /
• pp.1093-1098
• /
• 2012

Commercial Off the Shelf(COTS) Integrated circuits(ICs) are being increasingly considered for use in space and military applications. Therefore, There is a need to implement standard tests and requirements to ensure reliability of COTS ICs. This paper presents an overview of the ICs screen procedure and methods under the European Cooperation for Space Standardization (ECSS) and Tests Method Standard Microcircuits (MIL-STD-883). We describes the COTS ICs screen test guidelines that are mainly focused after encapsulating. In addition, COTS linear bipolar IC is investigated to evaluate the reliability requirements. The experiment results showed that COTS IC is satisfied with high reliability requirements.