• Journal of Satellite, Information and Communications
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• v.10 no.2
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• pp.80-85
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• 2015

In this paper, we present, an indstrial RFID layered microstrip patch antenna is designed using an inset feed method in order to improve recognition rates in a long distance as tags are attached to metal object by improving a problem of feeding power in fabricating metal tags and reducing effects of metallic object. The inset feed shows a distinctive characteristic that has no separation between emitters and feed lines differing from a structure with the conventional inductive coupling feed. This structure makes possible to produce a type that presents a low antenna height and enables impedance coupling for tag chips. Although it shows a difficulty in the impedance coupling due to increases in the parasite capacitance between a ground plane and an emitter in an antenna according to decreases in the height of a tag antenna, it may become a merit in designing the tag antenna because the antenna impedance can be determined as an inductive manner if a shorted structure is used for feeding power. Therefore, in this paper the microstrip patch antenna is designed as a modified type and applies the inset feed in order to reduce effects of metallic objects where the antenna is be attached. Also, the antenna uses a multi-layer structure that includes a metal plate between radiator and ground instead of using a single layer.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.1
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• pp.132-140
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• 2009

For human exposure assessment of UHF RFID system, electric field distribution of commercial 900[MHz] RFID antenna was measured and analyzed. Also, SAR(Specific Absorption Rate) of RFID antenna was calculated by simulation, and compared with basic restrictions in EMF guidelines. For EMF exposure assessment according to EN and IEC standards, the reader was tested for the normal operation, and electric field from RFID antenna was measured at various distances and angles. For electric field measurement, narrow band isotropic electric field probe was used, and the measurements were made at 0.3, 0.5, 1.0 and 1.5[m] for every 15[$^{\circ}$] angle from the antenna. Also, the rationale for measurement distance in EN and IEC standards is analyzed from the measurement results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.1-8
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• 2016

Automation of inventory management in a steel plate factory was a difficult problem unresolved for a long time. And now, it is also necessary to work diligently in the steel industry on efficient inventory management of thick plates. So far, the environmental characteristics of stacked thick plates means it is not easy to apply advanced technology for their automatic identification. In this paper, we propose a thick-plate robotic scanning system based on radio-frequency identification (RFID) that can provide quick and accurate inventory management by acquiring plate information after the scanning automatically recognizes the RFID tags under difficult load conditions. This system is equipped with a crane to move the plates in a pulled-up operation. It is equipped with a plate-only linear dipole antenna only for scanning the position of the plate tag. Only the linear dipole antenna, while moving the x-axis and y-axis information, automatically identifies the tag information attached to the plate. The tag information acquired by the system is used for stockpiling and is managed by steel plate inventory control software. The effectiveness of the proposed system is verified through field performance evaluation. As a result, the recognition rate of the plate tags is 99.9% at a maximum distance of 320 cm. The developed thick-plate antenna showed excellent performance compared to an existing commercial antenna.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.12 s.115
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• pp.1240-1248
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• 2006

This paper presents an UHF band(911 MHz) RFID tag antenna which has near-isotropic radiation pattern and easy conjugate impedance matching characteristics to any commercial chips of usual practice through the application of an inductively-coupled feeding. The proposed antenna of compact size $40{\times}46mm\;(0.12{\times}0.14{\lambda})$ has, at normal incidence, the maximum RCS of $-18.5dBm^2$ and the 3 dB RCS bandwidth of 9 MHz(1 %) in case of short chip load. It has the maximum and minimum RCS' of $-16.9dBm^2\;and\;-21.4dBm^2$ depending on the incident angles. The difference of about 4.5 dB is relatively small compared with that (about 70 dB) of a pure dipole antenna. The designed antenna has been fabricated and its RCS' have been measured varying the angles of incidence. The measured RCS' have been found to have good agreement with the simulated ones.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.1
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• pp.1-7
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• 2016

In this paper, the compact CPW-fed slot antenna for WLAN applications is proposed. While the proposed antenna with size of only $20{\times}18{\times}1mm^3$ is consisted of double stub and folded slot, the antenna for 2.4 GHz band and 5 GHz band is designed and fabricated with optimized parameters obtained by simulation. Proposed antenna is fabricated with FR-4 substrate to the thickness of 1.0 mm. By obtaining the measured return loss level of < -10 dB at dual-band, we showed that it is operated as antenna for WLAN applications, and then it is also expected to be usable as antenna for RFID.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.525-529
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• 2009

In this paper, microstrip patch antenna with diagonal slotted type using RFID is designed. This microstrip patch antenna is designed by considering the properties of critical parameter like the size, the truncating dimension, position of feed power and the height of airspace. the designed microstrip patch antenna has the lowest return loss in 915MHz, and in case of the voltage standing wave ratio(VSWR) is less than 1.2 under return loss -16dB, it has bandwidth of about 26MHz. Also, the microstrip patch antenna has the gain of 6dBi on the center frequency of 915MHz band and 2.8dB in the rate of reduction.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.4
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• pp.871-876
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• 2005

Theme park automation system is developed by using the RFID sensor reader, IIS web server, ASP.NET and MSSQL database in this paper. Its operation is that park entrance people checked automatically when he who possessed the ta8 passed the reader acquisition bound and its tag information is sent to the host computer through the RS-232 data acquisition system. Tag information and time data will be stored in the RFID database tables and reused to extract and distribute the entrance people for the purpose of each arrangement of each entertainment devices. First of all, we developed interface program between host and reader and then, programmed the related web site and database connection function using ASP.NET with $C\#$ and MSSQ. We also design and make an production of external Ant. to extend the acquisition range up to $30\~40$ cm using copper PCB plate. We confirmed the performance through the RFID test bed site.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.12B
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• pp.1468-1474
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• 2009

This paper shows an UHF RFID metallic tags using a Cavity structure for a long reading range. The reading range of a general passive tag is limited because the EIRP of a reader system is limited as 36㏈m by ISO 18000-6. To extend the reading range, the tag antenna should have a high gain antenna structure. The designed tag antenna is recognized over 10m range with a Cavity structure. The directivity pattern and the performance of the tag with the Cavity structure is stable when it is attached to a metallic object. The designed tag antenna has two kinds as cavity thickness. The sizes of designed tag antennas are $176\;{\times}\;52\;{\times}\;10\;mm$ and $176\;{\times}\;61\;{\times}\;30mm$ They can be attached to a large metallic materials and heavy equipments. The measured reading ranges of the tags are about 11m and 15m when they are attached to a metallic object.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.10
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• pp.885-894
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• 2015

In this paper, it can be applied to a walkie-talkie, the RFID / USN 920 MHz band(917~923.5 MHz) and WiFi 2.4GHz band(2.4~2.483 5GHz) return loss is 10 dB over the band, on-board dual band with omni-directional radiation characteristics is proposed. The basic structure designed antenna is used meander monopole antenna. It was used as double stubs and tabs for antenna designs that meet the criteria proposed. The double stub and the tab affects the reactance of the antenna to form a common-mode and differential-mode in the stub to improve the antenna characteristics and return loss in the bandwidth, gain and radiation characteristics. The system size of walkie-talkie is $52{\times}77mm^2$, the size of the antenna is limited to $52{\times}15mm^2$, the thickness of FR4 dielectric substrate is 0.8 mm, FR4 dielectric constant 4.4 is used. For experimental results, the return loss is measured more than 10 dB, the maximum gain is measured 1.95 dB, the maximum bandwidth is measured 360 MHz, the radiation characteristic is measured omni-directional. By a walkie-talkie terminal design applying the results of the paper, the handset's price competitiveness and production efficiency can be improved.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2010.09a
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• pp.326-329
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• 2010

현재 시행 중인 승용차 RFID 요일제는 제한적인 설치장소와 RFID 설치시 많은 비용이 소비된다. 따라서 본 연구에서는 기존의 RFID 승용차 요일제 방식과 달리 효율성을 높이고 비용을 절감할수 있는 BMS(BUS Management System)를 활용한 버스 RFID system에 관한 방안을 제안한다. 제안하는 방안은 버스 RFID system은 대구시의 시내 버스 뒤편에 양쪽 상단에 RFID 안테나를 설치하여 대구시의 주요 도로를 운행 하며 승용차 요일제를 미준수 여부를 파악하는 것이다. 기존의 고정형 RFID는 설치 위치를 우회 할수 있지만 버스 RFID는 항상 이동하며 감지 하기때문에 차량의 우회에 따른 미확인 경우를 줄일 수 있다. 또한, BMS 활용으로 설치비용을 절감하여 비용대비 효율성을 제고할 수 있을 것으로 예상된다. 구체적인 방안 마련을 위하여 주요도로 버스노선도 파악, 중첩지점 그리고 기존의 승용차 요일제 시스템과 비교 분석을 하여 성능 평가들 실시하는 것에 주안점을 두고 연구를 수행하였다.