• The Journal of the Korea Contents Association
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• v.7 no.11
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• pp.102-110
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• 2007

In this paper, a portable RFID reader which operated in 900MHz UHF band is designed and fabricated and the characteristics of the manufactured portable RFID reader is analyzed through measurement. Analysis of measurements results is achieved based on EPC Class 0 standards that proposed by EPC Global. The proposed RFID reader communicate with tags about 11kbps speed, and have 20 dBm for its maximum RF output power. The proposed portable RFID reader can recognize maximum 68 tags per second, and when reader's output power is 20 dBms, maximum recognition distance is 30cm. And the total size of implemented RFID reader is $71mm{\times}55mm$, that is the maximum 90%, minimum 14% reduced size compared with marketed product.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.1
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• pp.15-21
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• 2016

In this paper, we considered a design method of a compact quasi-Yagi antenna for portable UHF RFID readers. The antenna consists of a dipole driver and a reflector printed on a dielectric substrate, and it is fed by a microstrip line. In order to reduce the antenna size, the dipole and reflector are bent and the balun between the feeding microstrip line and coplanar strip (CPS) line is integrated within the CPS line. The effects of the geometrical parameters of the proposed antenna on the antenna performance are examined, and the parameters are adjusted to be suitable for the operation in UHF RFID band (902-928 MHz). The size of the fabricated antenna is $70mm{\times}75mm$, and the experiment results reveal a frequency band of 892-942 MHz for a voltage standing wave ratio < 2, a gain > 3.5 dBi, and a front-to-back ratio > 6.6 dB over the frequency band for UHF RFID.

• Journal of Korea Multimedia Society
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• v.10 no.4
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• pp.492-505
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• 2007

Currently, most procedures in domestic facility management systems are performed by hand. However, these manually operated facility management systems involve critical limitations, such as a waste of manpower to store collected data into a database, intentional or accidental loss of data consistency (mainly due to a lack of the ability to recognize and deal with frequent changes of facility status in realtime), and so on. To overcome the limitations of such manually operated facility management systems, the following capabilities must be supported. First, the changes in facility status must be recognized in realtime. Second, the data collection process must be secure and reliable to prevent fabrication of collected data and preserve data integrity. Third, the data collection devices must be portable to help the manager collect data about their facilities. To address these problems, we design and implement a novel facility management system using portable RFID, which is designed to support these functionalities and thus help reduce administrative costs. Through extensive experiments, we observed that our system improved the accuracy and reliability of facility check process and helped cut administrative costs by significantly reducing failure frequency.

• Journal of Korea Society of Industrial Information Systems
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• v.11 no.2
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• pp.98-102
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• 2006

Recent development of Information Technology, the ubiquitous computing environment is on the rise. At the same time, RFID technology and its related applications are actively investigated. In this paper, a portable merchandise information providing system using cheap wireless transmission module is developed in order to overcome the mobility limitation of the wired RFID system. The TRF6901 chipset of 900MHz band from TI is used for the wireless transmission module and the MPS430F149 is used for the MPU. It is expected that the developed system can be applied to numerous innovative wireless applications such as library circulation desk for lending service and automated door system for entrance control.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.4
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• pp.411-417
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• 2008

This paper presents the miniaturization of circularly polarized microstrip patch antenna for UHF-band RFID portable reader. The proposed antenna has a group of four I-slots on a conventional corner-truncated square microstrip patch and it is shown that the antenna size is reduced compared to the antenna without I-slots. A 76 mm by 76 mm small antenna with four I-slots is fabricated with 6.4 mm thick FR4 substrate and its 10 dB return loss bandwidth, the gain and the axial ratio are measured to be $938{\sim}975\;MHz$, $-0.88{\sim}-2\;dBi$, and $3.27{\sim}13.21\;dB$ within the 10 dB return loss bandwidth, respectively.

• Journal of IKEEE
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• v.24 no.1
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• pp.368-371
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• 2020

In this paper, we propose a linear tapered slot rectifying antenna for a portable UHF-band RFID system. Since the proposed rectifying antenna does not use a dielectric substrate, the planar antenna is implemented with a thin metal thickness. The rectifier circuit converts input RF power into output DC voltage using a voltage doubler circuit based on two anti-parallel schottky diodes. The rectifying antenna is integrated by the voltage doubler circuit into a linear tapered slot antenna. For conjugate impedance matching of the rectifying circuit and the linear tapered slot antenna, the source-pull method was utilized by adjusting the angle of the tapered slot and the length of the antenna feed line. The proposed antenna prototype has been verified with the electrical and radiation characteristics through RF-DC conversion and far-field radiation test in open space measurement environment. Finally, the proposed antenna is realized to 0.23-wavelength (75 mm) and 0.18-wavelength (60 mm) at 915 MHz center frequency.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.11
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• pp.2424-2430
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• 2012

The current Navigation System for the Visually Impaired Person has a short and limited communication distance and can't receive enough information from Visually Impaired Person to assist directly. In addition, because the path is dangerous and incomplete for the Visually Impaired Person, moving with White Stick is still inconvenient and dangerous. To solve this problem we implement communication that can send and receive video, voice, location information between the Visually Impaired Person's Smart Portable Navigation System Development and assistant's PC.

• Journal of Broadcast Engineering
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• v.19 no.6
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• pp.934-941
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• 2014

In this paper, we present a low profile 2-layered meander built-in monopole antenna for portable RFID reader using FDTD(Finite Difference Time Domain) method. The input impedance, return loss, and VSWR in the frequency domain are calculated by Fourier transforming the time domain results. The double meander 2-layer structure is used to enhance the impedance matching and increase the antenna gain. The measured bandwidth of the antenna is 0.895 GHz ~ 0.930 GHz for a S11 of less than -10dB. The measured peak gain of proposed low profile RFID built-in antenna is 2.3 dBi. And the proposed built-in antenna for portable RFID reader can offers relatively wide-bandwidth and high-gain characteristics, in respectively. Experimental data for the return loss and the gain of the antenna are also presented, and they are relatively in good agreement with the FDTD results. This antenna can be also applied to mobile communication field, energy fields, RFID, and home-network operations, broadcasting, and other low profile mobile systems.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.170-173
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• 2006

기존의 바코드와 같은 인식장치는 여러 가지 면에서 USN 환경 에서 사용하기에 상당한 제약이 따르게 된다. 그러나 RFID 시스템을 사용하면 이런 문제점들을 해결할 수 있다. RFID 기반의 시스템은 RFID 리더와 태그, 그리고 RFID 태그가 가지는 정보를 활용하기 위해서 사람이 관리하는 데이터 서버가 필요하다. 본 연구에서는 이를 응용하여 관람객에게 효과적으로 전시물을 안내해주는 2.45GHz 규격의 이동형 RFID 리더와 PDA를 이용한 전시관 어플리케이션을 구현하였다.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.2 s.302
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• pp.19-26
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• 2005

This paper is about designing and implementation of Multi-Function UHF RFID Reader Platform that receives and processes RFID tag data from the tags, and transmits the data to PC server through Bluetooth, USB, RS-232 or Ethernet. This reader system is composed of RFID module, ARM processor, RS-232 interface, USB, Ethernet MAC interface, Bluetooth etc.. This paper also provides a brief overview and concept of RFID reader, and proposes the design and implementations of the RFID reader platform. The paper evaluates and analyzes two practical implementations, fixed type and portable type.