• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.12
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• pp.1438-1446
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• 2010

In this paper, we compared and analyzed the antenna characteristics such as bandwidth, efficiency, and readable range in terms of the size and the number of turns of the multiple meander RFID tag antenna in the UHF band. The sizes of the each antenna are $20.0{\times}19.7$, $25.0{\times}24.8$ and $30.0{\times}29.7\;mm^2$. The bandwidths of the antennas for VSWR<5.8 are 857~963 MHz, 844~965 MHz, and 844~968 MHz which cover the worldwide UHF RFID bandwidth. The readable range of the antenna was greatly affected by the efficiency and gain of the antenna which depends on the size and the number of turns of the meander antenna.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.3
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• pp.420-426
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• 2008

In this paper, we present RFID Tag Antenna at 433MHz which can be available for RFID system. The antenna is composed of microstrip type antenna, whose dimension could be reduced by applying fractal theory. Simulated return loss and gain at 433MHz are -20.9dB, -3dBi. But there are some deviation on the point of resonance frequency between simulated and measured results. By modifying the antenna's feeding point, we obtain - l5dB return loss and verify the utility of proposed antenna.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.1
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• pp.75-82
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• 2009

In this paper, we proposed a U-shaped broadband RFID tag antenna with a parasitic element operating at UHF band. The proposed tag antenna consists of a U-shaped half wavelength dipole antenna and an inverse U-shaped parasitic element inside the U-shaped dipole antenna. In order to have good impedance matching, the commercial tag chip is attached to the lower center of the rectangular shaped feed. On the condition of VSWR<2, the tag antenna had the measured bandwidth of 4.96 % from 882 to 927 MHz and showed the gain deviation of less than 3.16 dB. On the condition of VSWR<5.8, the tag antenna satisfies the worldwide UHF RFID bandwidth and is showed the gain deviation of less than 5.07 dB. The minimum gain deviation characteristic appears near the center of bandwidth which minimizes variation of gain deviation characteristic with respect to the frequency.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.26 no.3
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• pp.344-349
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• 2017

In this study, we developed a process technology to fabricate RFID tag antennas using a one-sheet inlay micro-pattern forming process by press-molding RFID tag antennas on insulation sheet layers, such as polymer films, using ultrasonic longitudinal vibration. In addition, a fine pattern applicable for RFID tag antennas was manufactured using a $25{\mu}m$ thick thin-plate square wire; this is in contrast to the method that uses a conventional round wire. The developed ultrasonic indentation process can be used to fabricate fine pattern of the RFID antenna using one piece of equipment. The simplified manufacturing process technology has a shorter manufacturing time and is more economical. The developed RFID tag antenna forming technique involves pressing the $25{\mu}m$ square wire directly on the thin sheet insulation sheet of maximum thickness $200{\mu}m$, using a 60 kHz ultrasonic tool horn.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.9
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• pp.2253-2265
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• 2012

A novel folded dipole type microstrip patch antenna designed for ultrahigh frequency (UHF) band radio frequency identification (RFID) tag is presented in this paper, which can be used on the metallic objects. The presented antenna is fabricated on a very thin Rogers 5880 substrate with a thickness of 0.508 mm. The structure consists of two folded dipole and two symmetrical shorting pins placed at both sides of feed point. An adjustable frequency response can be easy obtained via modify the location and radius of the shorting pins. The antenna has been analyzed by full wave simulations soft. The simulated bandwidth is about 67.2 MHz, which covers the Europe and North America UHF RFID frequency range. A manufactured prototype has been fabricated and measured to demonstrate the antenna performances. The simulation results agree with the measurement data well. The measured maximum reading range of the prototype can be reached 4.1 m in free space, and 3.2 m on a metal plate whose size is $150{\times}150{\times}8mm^3$.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.1
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• pp.68-75
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• 2007

A single chip NFC transceiver supporting not only NFC active and passive mode but also 13.56MHz RFID reader and tag mode was designed and fabricated. The proposed NFC transceiver can operate as a RFID tag even without external power supply which has dual antenna structure for initiator and target. The area increment due to additional target antenna is negligible because the target antenna is constructed by using a shielding layer of initiator antenna. The analog front end circuit of the proposed NFC transceiver consists of a transmitter and receiver of reader/writer block supporting NFC initiator or RFID reader mode, and a tag circuit for target of passive NFC mode or RFID tag mode. The maximum baud rate of the proposed NFC device is 212kbps by using UART serial interface. The chip has been designed and fabricated using a Magnachip's $0.35{\mu}m$ double poly 4-metal CMOS process, and the effective area of the chip is 2200um by 3600um.

• Journal of the Microelectronics and Packaging Society
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• v.16 no.1
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• pp.21-25
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• 2009

By using Si CMOS process, small RFID tag antenna were fabricated on Si substrate and their electrical properties were evaluated. Firstly, tag antenna pattern and the electromagnetic properties were simulated with HFSS. The frequency was 13.56 MHz, the line-width and line-gap were modeled in the range of $50{\sim}200{\mu}m$. S parameters, SRF, and Q value were calculated from geometry. When the line-width and line-gap were $100{\mu}m$ and $100 {\mu}m$, respectively and the loop-turn was 10, the SRF was 80 MHZ and the Q value was ca. 9. When the microstrip antenna pattern of aluminum $2{\mu}m$ was fabricated by using DC sputtering, Vpp of ca. 4.3 V was obtained when the reader and tag were closely contacted.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.3
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• pp.23-30
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• 2012

In this paper, we propose a new near-field reader antenna for 900 MHz RFID. The proposed antenna consists the micro-strip antenna with the periodic structure. The overall dimension of the antenna is $313mm{\times}152mm{\times}14mm$. The antenna has the uniform E-field distribution in near field region and the heart-shaped radiation beam pattern (Peak gain=-2 dBi). The transmitted power range is from 17 dBm to 23 dBm. We focus on minimizing the detected error by suppressing the reflected power from the metal, which is attached to the surface by tag, and by reducing the transmitted power from tag.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.1 no.1
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• pp.19-31
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• 2007

RFID tag is detected by an RFID antenna and information is read from the tag detected, by an RFID reader. RFID tag detection by an RFID reader is very important at the deployment stage. Tag detection is influenced by factors such as tag direction on a target object, speed of a conveyer moving the object, and the contents of an object. The water content of the object absorbs radio waves at high frequencies, typically approximately 900 MHz, resulting in unstable tag signal power. Currently, finding the best conditions for factors influencing the tag detection requires very time consuming work at deployment. Thus, a quick and simple RFID tag detection scheme is needed to improve the current time consuming trial-and-error experimental method. This paper proposes a back-propagation learning-based RFID tag detection prediction scheme, which is intelligent and has the advantages of ease of use and time/cost savings. The results of simulation with the proposed scheme demonstrate a high prediction accuracy for tag detection on a water content, which is comparable with the current method in terms of time/cost savings.

• Journal of IKEEE
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• v.12 no.3
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• pp.144-150
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• 2008

This paper describes the design of a coplanar-stripline(CPS) antenna without via hole in microstrip patch type for 910MHz RFID tags using the HFSS simulator. In order to obtain the simplified fabrication design of the antenna, we have used only an impedance matching network to match the impedance of a RFID-tag chip to that of the antenna, not using bandpass filter(BPF). In advance of the optimized antenna design, we have obtained and shown a good agreement compared with the published antenna for 5.8GHz in order to verify the simulation parameters in the HFSS. Based on the verified simulation parameters in the HFSS, we have designed and optimized the 910MHz-CPS-type microstrip patch antenna. The designed simulation results of the antenna show that the proposed antenna is very proper for RFID tags with the 910MHz center frequency without via hole in the microstrip patch antenna.