• Journal of Korea Society of Industrial Information Systems
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• v.16 no.4
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• pp.1-7
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• 2011

In this paper, we design rectifing circuits at 910MHz, which is used for passive RFID system, for wireless power transmission system by using two types of schottkey diodes HSMS_2822 and HSMS 2852, and the RF-DC conversion efficiencies for the curcuits are compared and analyzed in terms of input power and load resistance. When the input power is -20 to 17dBm, the conversion efficiency for HSMS_2852 is larger than in case of HSMS_2822. The output voltage and current at the load of the fabricated rectifying circuit are measured through a dipole antenna when input power is transmitted by a RFID reader and the diatance varies. The measured ouput volatge and current for the distance of 50cm are 2.5V and 5.75mA.

• The Journal of Society for e-Business Studies
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• v.16 no.3
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• pp.113-127
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• 2011

An RFID system has been widely applied in many areas over the initial SCM application. In the literature enormous RFID applications in healthcare are documented to improve patient safety, patient/provider logistics, and the efficiency of collecting data. Based on the proposed 4-layered RFID system architecture, we introduce a case that implemented an UHF passive RFID-based tracking system in an outpatient clinic. Particularly, we propose a method to process RFID data that contains noise and missing reads. The proposed method for processing unreliable RFID data is capable to locate the tag accurately and provide additional business information. We finally conclude the paper with identifying obstacles and what is necessary to ensure system reliability.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.415-418
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• 2007

This paper presents the design and analysis of LNA-Mixer for 2.45GHz RFID reader. The LNA is implemented by PCSNIM method for low power consumption. The Mixer is implemented by using the Gilbert-type configuration, current bleeding technique, and the resonating technique for the tail capacitance. The connection between the two designed circuits is made by active balun. This LNA-Mixer has about 35dB for -40dBm input RF power, LO power is 0dBm and RF frequency is 2.45 GHz and IIP3 is -4dBm. The layout of LNA-Mixer for one-chip design in a $0.18-{\mu}m$ TSMC process has 2.6mm ${\times}$ 1.3mm size.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.4
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• pp.761-767
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• 2007

In this paper, we deal wih a concurrent dual band low noise amplifier for a Radio Frequency Identification(RFID) reader operating at 912MHz and 2.45GHz. The design of the low noise amplifier is based on the TSMC $0.18{\mu}m$ CMOS technology. The chip size is $1.8mm\times1.8mm$. To improve the noise figure of the circuit, SMD components and a bonding wire inductor are applied to input matching. Simulation results show that the 521 parameter is 11.41dB and 9.98dB at 912MHz and 2.45GHz, respectively The noise figure is also determined to 1.25dB and 3.08dB at the same frequencies with a power consumption of 8.95mW.

• The Journal of the Korea institute of electronic communication sciences
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• v.2 no.4
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• pp.199-202
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• 2007

In this paper, we examined the operating principle of a passive tag antenna for RFID system in UHF band. Based on the study, we proposed a novel RFID tag antenna which adopts the inductively coupled feeding structure to match antenna impedance to a capacitively loaded commercial tag chip. The proposed tag antenna consists of microstrip lines on a thin PET substrate for low-cost fabrication. The detail structure of the tag antenna were optimized using a full electromagnetic wave simulator of IE3D in conjunction with a Pareto genetic algorithm, and the size of the tag antenna can be reduced up to kr=0.27(2 cm2). We built some sample antennas and measured the antenna characteristics such as a return loss, an efficiency, and radiation patterns. The readable range of the tag antenna with a commercial RFID system showed about 1 to 3 m.

• 한국ITS학회:학술대회논문집
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• v.2006 no.10
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• pp.179-181
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• 2006

톨게이트에서 사용되는 UHF RFID 비발디 배열 안테나를 설계하였다. 안테나의 주파수 대역은 미국 기준의 RFID UHF 대역으로 $902{\sim}928MHz$이다. 안테나 설계는 먼저 단일소자 비발디 안테나를 설계한 후, 전력분배 비율 0.3:1:1:0.3으로 $1{\times}4$ 배열한 안테나로 설계하였다. 설계된 배열 안테나는 VSWR 2:1이하에서 $850{\sim}942MHz$인 S11 특성을 보였다. 이득은 최대방사 9.93dBi를 얻었다. 안테나 제작은 주파수를 높여 scale down하여, 1소자 비발디를 제작하고 이의 특성을 측정하였다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.3 s.357
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• pp.98-104
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• 2007

In this paper, the dual-band open loop antenna using a strip conductor for the RFID reader and Wireless LAN Application, which has a resonant frequency at 910MHz and 2.45 GHz, is proposed. Input impedance of antenna is matched with the feed line of 50 ohm by varying the length and width of sip conductor making up the antenna. The gain and directivity of antenna is enhanced as tuning the length of strip, and as also grooving the teeth shapes on the strip conductor. The size of fabricated antenna is $75mm\times100mm$. The return loss and the gain of fabricated antenna are -11.92 dB, 3.02 dBi at 910 MHz and -21.31 dB, 4.08 dBi at 2.45 GHz, respectively.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1422-1423
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• 2008

UHF 모바일 RFID 밴드에서 고선형성을 가지는 CMOS 공통 게이트 저 잡음 증폭기를 제안하였다. 제안된 공통 게이트 구성은 고선형성과 광대역 특성을 가진다. 저 잡음 증폭기는 0.35${\mu}m$ (one poly, four metals) CMOS 공정을 사용하여 제작되었고, 제작된 공통 게이트 저 잡음 증폭기의 특성은 잡음 지수 3.2dB, P1dB 1.4dBm, 전압 이득 13.4dB를 가진다.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.5
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• pp.1-10
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• 1999

A low power concumption 2.4 GHz one-chip transceiver MMIC was designed and fabricated using $1.0\mu\textrm{m}$ ion-implantation MESFET process and packaged on a 24 lead SSOP. In the transmitter mode, it revealed conversion gain of 7.5 dB, output IP3 of -3.5 dBm, and noise figure of 3.9 dB at 2.44 GHz with 3.9 mA current consumption. In the receiver mode, it revealed voltage sensitivity of 6.5 mV/$\mu\$W with 2 .0 mA current consumption. Comparing the fabricated MMIC with the results of MMICs reported elsewhere, it was shown that the fabricated MMIC had good performance. The low power consumption 2.4 GHz transceiver MMIC is expected to be used for various applications such as wireless local area networks, wireless local loops and RFID tags in ISM-band.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.205-207
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• 2006

In this paper, we present a design procedure of high linearity LNA using CMOS technology. To enhance the low linearity of the inherent CMOS transistor, we adopt the modified derivate superposition with adding external capacitor. The simulation of the designed LNA shows $IIP_3$ of +12-dBm, power gain of 13.8-dB, noise figure of 1.75-dB over the 900 MHz UHF RFID frequencies. The circuit draws the current of 4.2 mA from 1.8-V supply voltage.