• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.1
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• pp.175-181
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• 2015

In this paper, we develop a 2.4GHz ISM band wireless communication platform prototype based on embedded linux which support can be u-Hospital service. The developed system is available connecting between ARM920T processor board and FPGA board and linking IEEE 802.11b PHY board, AD/DA(10Bit) and RF(2.4GHz) board for wireless access. It is also can be utilized for the embedded system design with IEEE 802.11b/g Access Point(Option: IEEE 802.11a/b/g) test due to the Embedded Linux. Also, the developed system is possible to test and verify the radio access technology, Modem(OFDM etc) and IP(Intellectual Property) circuit. And make the most use of the system, we search for a expansion to that home and mobile healthcare, wellness service application.

• The Journal of Korean Institute of Information Technology
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• v.16 no.11
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• pp.77-84
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• 2018

In this paper, the circular polarization microstrip patch antenna using the T-junction power divider is proposed. The operating frequency of the proposed antenna is ISM band of 2.4GHz and the circular polarization is induced by feeding a phase difference of $90^{\circ}$ in two edges. The structure of the antenna consists of a general patch and a T-junction power divider. Furthermore, to optimize the proposed antenna, it is analyzed the reflection coefficient, the axial ration and the radiation pattern. The impedance bandwidth of the antenna is observed to be 40MHz within a range of 2.39 to 2.43GHz, similarly, the axial ratio bandwidth is observed having the bandwidth of about 12MHz in 2.398 to 2.410GHz range. The radiation pattern of the antenna is seen to be right circular polarization. Furthermore, the gain of the antenna is observed to be 2.04 and 3.4dBic at XZ and YZ-plane, respectively.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.101-105
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• 2011

This paper calculates protection distance to protect WiBro service from ISM(Industrial Scientific Medical) equipment which is used in the same frequency with WiBro. We analyze with a scenario that WiBro receiver is closed to ISM equipment which has interfering power of CISPR(International Special Committee on Radio Interference) 11 limit. As a result, the protection distance of 14 m was calculated by using MCL (Minimum Coupling Loss) for the worst case. And, the protection distance of 10 m was calculated to meet 5 % interference probability below by using MC(Monte Carlo) for statistic analysis in case of a interferer.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.100-103
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• 2002

본 논문에서는 무선 인터넷 사업 및 초고속 정보통신 인프라 구축과 관련하여 WRC-2003에서 새롭게 분배하기로 결정된 5GHz대역(5.135~5.35GHz, 5.47~5.725GHz)과 기존의 ISM 대역(5.75~5.85GHz)에 동시에 사용할 수 있는 스트립 라인 급전을 이용한 슬롯 안테나를 설계하였다. 무선통신 시스템의 박형화를 위하여 평면 내장형으로 설계하였으며 안테나의 크기는 5.04$\times$12.55$\times$2.0[mm]이며 FR-4($\varepsilon$$_{r}$=4.6)를 substrate로 사용하였다. 중심주파수 5.749GHz를 중심으로 10㏈ 기준대역폭 28.54%(4.929~6.561GHz)fmf 갖는다. 안테나의 이들은 약 4.2㏈i이다.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.326-329
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• 2003

In this paper, we designed and implemented a high power amplifier(HPA) to achieve the high Power Added Efficiency(PAE) over 40% at the 90W output power for the ISM-band(fo=2.45GHz). HPA presented in this paper has 3-stage drive amplifier and 1-stage final amplifier. In the final amplifier, we utilized balanced amplifier configuration with GaAs FET and each of two amplifiers has the push-pull configuration to increase PAE. From the measurement results, we obtained PAE of 42.95% at the 90.57W output power.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.113-117
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• 2003

This paper describes the design and the simulation results of the RF CMOS Class-E Power Amplifier for a 2.4GHz ISM band. This circuit is composed two connected amplifiers. where Class F amplifier drives Class E amplifier. The proposed circuit can reduce the total power dissipation of the driving stage and can work with higher efficiency. The power amplifier has been implemented in a standard $0.25{\mu}m$ CMOS technology and is shown to deliver 100mW output power to load with 41% power added efficiency(PAE) from a 2.5V supply.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.539-542
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• 2005

In this paper, we propose a wireless data access system, which used direct sequence spread spectrum method and the ISM band with 900MHz radio frequency. By applying bi-directional transmission between wireless transmitter and receiver, it can be effectively connected with any kinds of RF-ID with 900MHz ISM band. Therefore it could economically be used as peripheral equipments for RF-ID system.

• Journal of the Korea Society of Computer and Information
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• v.11 no.3
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• pp.79-86
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• 2006

In this paper, we implement the ad ballon control system in which a built camera monitors using bluetooth wireless communication with ISM(Industrial. Scientific and Medical) band. In the proposed system. the driving time of ad ballon is increased by adopting the mercury battery and light weight. An ad ballon with camera is easily controlled by Graphic User Interface using Linux based embedded system.

• The Journal of Information Technology
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• v.5 no.2
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• pp.47-54
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• 2002

OFDM ambient noise and entrain error that this research proposes in IEEE 802.11g, use 256-State 2/3 binary scale Convoulutional 8-PSK Modulations, FEC coding, PBCC and did speed of 12 Mbpses that belong on category of 5 GHzs Band FHSS way so that can be applied in 20 Mbpses DSSS'S generalization that is establishing Pyojunan in current IEEE embodying transmission device model who operate with the equal speed from 2.4 GHzs ISM Band important duty to DSSS way.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.472-474
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• 2019

We propose an antenna for subminiature sensor node in the marine IoT service based on low power wide area (LPWA) network. The proposed antenna is designed for multi-band in ISM band. The specification of the proposed antenna expressed here is also for multi-band service.