• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.4 no.1
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• pp.39-45
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• 2011

In this paper, the design method of portable signal analysis system is proposed and the hardware module is implemented for operation of base stations based on a common platform for mobile WiMax. The new signal analysis method is implemented as two modules; a broadband RF module and a DSP based digital signal analysis module. The RF module performs the RF-IF down conversion and gain control. And the digital module measure the base staion signal. The differences of performance are insignificant in the experiment results performed through the comparison of other fixed-large system and proposed system.

• Journal of the Korea Convergence Society
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• v.8 no.11
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• pp.85-91
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• 2017

This paper concerns the design of a matching module system enabling the RF signal to be harmonized between the new base stations (RRH) and the repeater in the same frequency band of the asynchronous transfer network. This matching system controls the RF Gain Control of the module while monitoring the quality of the quality. Additionally, the RF environment has been adapted accordingly to adjust the RF Gain Control to match the receiver characteristics of the relay. As a result of this study, we improved the quality of the interface between the new base stations and existing relays.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.12
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• pp.2417-2424
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• 2016

Small size and light weight is very important for components used in radar mounted platform such as airborne radar. Recently, the active phased array radar is developed as an array of antennas for thousands of transmit/receive modules to be used as a multi-function radar that can detect and track targets. In this case, the size and weight of the transmit/receive modules are critical factor for developing the radar. In this paper, we developed a compact transmit/receive module using the 10W RF MEMS switch domestically localizing and reduced the circuit area to about 86.5% compared to using a circulator. The developed module satisfies not only electrical requirements but also MIL-STD's environmental specifications. So it can be used in a military device. It can be used at adaptive tunable receivers, reconfigurable smart active antennas and wide band beam electrical steering antennas.

• The Journal of the Korea institute of electronic communication sciences
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• v.1 no.1
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• pp.8-19
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• 2006

The RF Module which can be adjusted for a digital terrestrial and multi standard(DVB-C, ISDB-T, DVB-H) reception is developed. The Module by single conversion does divide a broadband(45MHz~860MHz) broadcasting channels into three-bands(UHF, VHF_HIGH, VHF_LOW) to satisfy some electrical performances such as image signal rejection, phase noise, IF flatness etc and digital reception specifications such as analog and digital adjacent channel protection, co-channel protection which is important in environment with co-existence both analog and digital broadcasting systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.3A
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• pp.345-355
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• 2006

The RF Module which can be adjusted for a digital terrestrial and multi standard(DVB-C, ISDB-T, DVB-H) reception is developed. The Module by single conversion does divide a broadband($45MHz{\sim}860MHz$) broadcasting channels into three-bands(UHF, VHF_HIGH, VHF_LOW) to satisfy some electrical performances such as image signal rejection, phase noise, IF flatness etc and digital reception specifications such as analog and digital adjacent channel protection, co-channel protection which is important in environment with co-existence both analog and digital broadcasting systems.

• Journal of Satellite, Information and Communications
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• v.7 no.1
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• pp.75-81
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• 2012

This study is to design the transmitter and receiver of short range UWB(Ultra Wide Band) imaging radar that is able to display high resolution radar image for front area of a UGV(Unmanned Ground Vehicle). This radar can help a UGV to navigate autonomously as it detects and avoids obstacles through foliage. The transmitter needs two transmitters to improve the azimuth resolution. Multi-channel receivers are required to synthesize radar image. Transmitter consists of high power amplifier, channel selection switch, and waveform generator. Receiver is composed of sixteen channel receivers, receiver channel converter, and frequency down converter, Before manufacturing it, the proposed architecture of transceiver is proved by modeling and simulation using several parameters. Then, it was manufactured by using industrial RF(Radio Frequency) components and all other measured parameters in the specification were satisfied as well.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.3
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• pp.1-6
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• 2008

A dual band I/Q modulator which converts baseband input signals to 2.4GHz or 5GHz RF output has been proposed. The dual band I/Q modulator for 2.4GHz and 5GHz wireless LAN applications consists of $90^{\circ}$ phase shifter and wideband mixer. The I/Q modulator showed 15dB conversion loss at 2.4GHz and 16dB conversion loss at 5GHz. The sideband suppression is about 15dBc at 2.4GHz and 16dBc at 5GHz. Measured data shows 8.5% EVM at 2.4GHz, and 10% EVM at 5GHz for QPSK with symbol rate of 11Mbps. A carrier rejection is about 40dBc at 2.4GHz/5GHz band, and the I/Q modulator satisfied the output wireless LAN spectrum mask with baseband input signal.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.6
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• pp.31-36
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• 2022

In this paper, we present the design, manufacture and test results of Backend unit for SAR(Synthetic Aperture Radar) that can be applied on a small satellite. The Backend unit for SAR was designed with a control/storage board, TRX(transmission and receiving) board and a power supply board as a single unit in consideration of the applying of a small satellite. The control/storage board uses RFSoC to generate wideband chirp signal, generate operating timings, and perform control and calculations for SAR operation. The TRX board is designed to convert the wideband chirp signal generated by the control/storage board to the operating frequency of X-band by up-converting the frequency. Since small size, light weight, and low cost are important consideration for small satellite, MIL/Industrial grade components were appropriately applied and the at the same time it was designed to ensure mission life through the radiation test, analysis and space environment tests.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.12
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• pp.57-63
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• 2016

This paper describes implementation of the RF frequency synthesizer with $0.18{\mu}m$ silicon CMOS technology being used as an application of the IEEE802.15.4g SUN sensor node transceiver modules. Design of the each module like VCO, prescaler, 1/N divider, ${\Delta}-{\Sigma}$ modulator, and common circuits of the PLL has been optimized to obtain high speed and low noise performance. Especially, the VCO has been designed with NP core structure and 13 steps cap-bank to get high speed, low noise, and wide band tuning range. The output frequencies of the implemented synthesizer is 1483MHz~2017MHz, the phase noise of the synthesizer is -98.63dBc/Hz at 100KHz offset and -122.05dBc/Hz at 1MHz offset.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.4
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• pp.23-31
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• 2018

This paper presented the implementation and design of the 2T-2R wireless HD video streaming systems over 1.7 GHz frequency band using 3GPP LTE-TDD standard on NI USRP RIO SDR platform. The baseband of the system used USRP RIO that are stored in Xilinx Kintex-7 chip to implement LTE-TDD transceiver modem, the signal that are transmitted from USRP RIO up or down converts to 1.7 GHz by using self-designed 1.7 GHz RF transceiver modules and it is finally communicated HD video data through self-designed 2x9 sub array antennas. It is that communication method between USRP RIO and Host PC use PCI express x4 to minimize delay of data to transmit and receive. The implemented system show high error vector magnitude performance above 32 dBc and to transmit and receive HD video in experiment environment anywhere. The proposed hybrid beam forming system could be used not only in the future 5G mobile communication systems under 6 GHz frequency band but also in the systems over 6 GHz frequency band like ones in mmWave frequency bands.