• Bulletin of the Korean Space Science Society
• /
• 2004.10b
• /
• pp.344-346
• /
• 2004

KOMPSAT-2 (Korea Multi Purpose Satellite 2) which is scheduled to launch in 2005 year will communicate with KARI TTC (Tracking, Telemetry, and Command) station flying along sun synchronous orbits (685 km). The command from KARI TTC passes S-band omni-antenna, RF assembly, and transponder and finally reachs OBC (On Board Computer). The telemetry from KOMPSAT-2 arrives at KARI TTC through inverse procedure. In this paper, RF compatibility test between KOMPSAT-2 and KARI TTC station is demonstrated. RF interface for this test was established through real space and uplink signal test and downlink signal test and uplink & downlink signal test were performed.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.42 no.8
• /
• pp.674-682
• /
• 2014

Radio Frequency Test Set (RFTS) is essential to verify Telemetry, Command & Ranging (TC&R) RF subsystem of both Low Earth Orbit (LEO) and Geostationary Earth Orbit (GEO) satellite during Assembly Integration & Test (AI&T). The existing RFTS was specialized for each project and needed to be modified for each new satellite. The new design enables RFTS to be used in various projects. The hardware and software was designed considering this and therefore it could be directly used in other projects within a similar test period without modification or inconvenience. It will be also easily controlled, modified, and managed through the extension in modularization according to each function and the use of COTS (commercial on-the-self) and this will improve system reliability. A more reliable RF test measurement is also provided in this new RFTS by using an accurate reference clock signal.

• Aerospace Engineering and Technology
• /
• v.6 no.2
• /
• pp.52-59
• /
• 2007

Telecommunication satellite consists of a bus system and an RF payload system with high efficiency and high gain reflector antennas. Antenna measurement and also RF system performance (antenna under test, payload and satellite level) have to be evaluated enough before launching in the far-field range or equivalent test range. Basically far-field range is required in a range from two hundred meters to several kilo meters, and it is highly constrained to the externa1 environment, like the RF and the whether environment So the compact antenna test range is developed and used efficiently without external environments as in-door facility. This paper describes the configuration of the compact antenna test range, the range error, and the physical concept of the plane wave illumination Also, it provides a overall design of the anechoic chamber and range parameter values to accommodate the precision measurements in antenna test range.

• Nuclear Engineering and Technology
• /
• v.34 no.3
• /
• pp.211-217
• /
• 2002

A 1-MW vacuum feedthrough for the KSTAR ICRF antenna is fabricated and high power RF test is performed. It is designed to have two alumina $(Al_2O_3)$ ceramic cylinders and O-ring seal instead of a brazed seal for good mechanical and thermal strength, which is important in long pulse or steady state operation. For cooling of the ceramics, dry air is circulated in a space between the two cylinders and the outer conductor. Independent cooling water channels are installed to cool the inner conductor of the feedthrough. RF high voltage test is performed using two kinds of ceramics with the purities of 99.7% and 97%. Stable operation is possible with the RF voltage of 30 kVp at long pulse of 300 sec without any severe damage.

• Journal of the Microelectronics and Packaging Society
• /
• v.4 no.2
• /
• pp.79-83
• /
• 1997

본 연구에서는 휴대용 전화기 및 무선 LAN 의 핵심부품인 RF-Switch Module의 초소형화 설계기술, 표면실장기술, 고주파설계기술, 소형화 SMD기술, Test 기술 및 RF-Switch Module 활용기술 등을 개발하였으며 RF-Switch Module의 설계기반 마련 및 대외 경쟁력 있는 RF-Switch Module의 초소형화 기술을 확보하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2003.10a
• /
• pp.818-823
• /
• 2003

본 논문에서는 입력 매칭(input matching) BIST(Built-In Self-Test) 회로를 이용한 RF font end의 새로운 결함 검사방법을 제안한다. BIST 회로를 가진 RF front end는 1.8GHz LNA(Low Noise Amplifier: 저 잡음 증폭기)와 이중 대칭 구조의 Gilbert 셀 믹서로 구성되어 있으며, TSMC 0.25$\mu\textrm{m}$ CMOS 기술을 이용하여 설계되었다. catastrophic 결함 및 parametric 변동을 가진 RF front end와 결함을 갖지 않은 RF front end를 판별하기 위해 RF front end의 입력 전압 특성을 조사하였다. 본 방법에서는 DUT(Device Under Test: 검사대상이 되는 소자)와 BIST 회로가 동일한 칩 상에 설계되어 있기 때문에 측정할 때 단지 디지털 전자계와 고주파 전압 발생기만이 필요하며, 측정이 간단하고 비용이 저렴하다는 장점이 있다. BIST 회로가 차지하는 면적은 RF front end가 차지하는 전체면적의 약 10%에 불과하다. 본 논문에서 제안하는 검사기술을 이용하여 시뮬레이션해 본 결과 catastrophic 결함에 대해서는 100%, parametric 변동에 대해서는 약 79%의 결함을 검출할 수 있었다.

• Proceedings of the KSRS Conference
• /
• 2007.10a
• /
• pp.500-503
• /
• 2007

During the COMS system level test, the RF compatibility will be performed in order to verify that there is no issue in RF interface between satellite and COMS ground station, namely SOC (Satellite Operation Center) before the launch. As used for KOMPSAT1, the RF coaxial cable was chosen to be used to connect satellite and SOC with various advantages as compared with ground antennas. As the preparation step, RF cable and required multiplexer were tested in advance. This paper suggests the way for the RF compatibility tests between the satellite and the SOC over RF cable interface and presents the estimated level diagram as the signal power analysis result.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2011.10a
• /
• pp.353-356
• /
• 2011

A Signal Receiving system to collect and analyze RF signals should be verified under simulated RF signal environment prior to verification on operation in fields and tested by using simulated RF signals in order to estimate its electrical performance. Generally, typical Signal Receiving system can measure, analyze frequency, pulse modulation, scan modulation, phase modulation on pulse, frequency modulation on pulse etc on RF signals. These RF signals should be generated from simulated RF sources in laboratory. Also the simultaneous RF signals should be simulated on laboratory. This paper describes the results of studying effective simulated RF signal source generation, the methods of the precise RF test signal generation in consideration of operational scenario.

• Journal of the Korean Institute of Navigation
• /
• v.22 no.1
• /
• pp.51-54
• /
• 1998

In this paper, RF receiver for CDMA system which has 10 MHz in the channel bandwidth has been designed and fabricated. The designed and fabricated RF receiver is shown useful in operation and the performance has been confirmed by experiments. The results are to be used for establishment of a broadband CDMA wireless access specification standard for WLL system in 2.3 GHz band.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.44 no.4
• /
• pp.28-39
• /
• 2007

This paper presents a programmable RF DFT (Radio Frequency Design-for-Testability) circuit for low noise amplifiers. We have developed a new on-chip RF DFT circuit that measures RF parameters of low noise amplifier (LNA) using only DC measurements [1, 2]. This circuit is extremely useful for today's RFIC devices in a complete RF transceiver environment. The DFT circuit contains test amplifier with programmable capacitor banks and RF peak detectors. The test circuit utilizes output DC voltage measurements and these measured values are translated into the LNA specifications such as input impedance and gain using the mathematical equations. Our on-chip DFT circuit can be self programmed for 1.8GHz, 2.4GHz and 5.25GHz low noise amplifiers for GSM, Bluetooth and IEEE802.11g standards. The circuit is simple and inexpensive.