• 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.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.3
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• pp.376-379
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• 2014

In this paper, we designed more improving a dual-band power amplifier than the transceiver of RFID reader that operates at 910 MHz and 2.45 GHz. A dual-band power amplifier has two circuits. One matching circuit is composed lumped element in the band of 910 MHz. The other matching circuit using distributed element in the high band of 2.45 GHz. So, this dual-band power amplifier works as Band Rejection Filter in the band of 910 MHz but in the high band of 2.45 GHz works as Band Pass Filter. Therefore, this is composed a microstrip transmission line. A power amplifier is showed gains of 8 dB output power at 910 MHz and 1.5 dB output power at 2.45 GHz. If input power is 10 dBm, both of bands output 20 dBm.

• Journal of Navigation and Port Research
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• v.32 no.5
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• pp.363-368
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• 2008

This paper presents a miniaturization design technique of radio frequency identification (RFID) tag antenna operated in 910 MHz band. Miniaturization structure design for a tag antenna is performed by structure application of the folded dipole and meander line. In order to realize the maximum power transmission, imaginary part of a chip impedance and a tag antenna impedance is matched by complex conjugate number. The optimized tag antenna size is $50\;nm\;{\times}\;40\;nm\;{\times}\;1.6\;nm$ and its size is reduced about 62 % comparison with antenna size of reference [4]. The measured results of fabricated tag antenna are confirmed the reasonable agreement with prediction. The read range of the tag antenna with chip observed about 5 m.

• The Journal of the Korea Contents Association
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• v.7 no.4
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• pp.30-38
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• 2007

In this paper, UHF band RFID reader antenna using filbert curve fractal structure and adding the partially grounded plane at the bottom of antenna, which has a resonant frequency at 910MHz, is proposed. Input impedance of antenna is matched with the feed line of 50ohm by varying the length and width of line segment making up the antenna, and by moving the position of via hole. The gain and directivity of antenna is enhanced as varying the dimension of the partially grounded plane and adding the line segment. The size of fabricated antenna is $68mm\times68mm$. The impedance band width(VSWR<2) is $882\sim942MHz$. The return loss and the gain of fabricated antenna are -18.2dB, 5.3dBi at 910MHz.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1389-1390
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• 2008

In this paper, a This paper presents the Hilbert curve Fractal Antenna has properties of Self-similarity and Plane-Filling. In case of fractal antenna is very useful to be small and multiple resonant. The antenna has a resonant frequency of 910MHz and 2450MHz base on RFID(Radio Frequency IDentification). In particular, we designed tag antenna by the $4^{th}$ repeat. According to the repeated number of fractal structures, resonance frequency became looking downward. Theses presented Frequency, Such as 910MHz and 2450MHz, at $S_{11}$ is -31dB and -19dB, bandwidth 120MHz and 90MHz to VSWR 2:1.

• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.1B
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• pp.78-84
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• 2010

A fixed 900 MHz near field RFID system is developed to provide information; market efficiency, jewelry information and the circulation history information in real time, to the customers. The developed RFID system for the jewelry management consists of a reader, antenna and a CPU in a integrated type. The system size is $38\;{\times}\;25\;{\times}\;19\;cm^3$, the operated frequency band of the reader antenna is 905 ~ 926 MHz. The maximum gain of the embedded reader antenna is 5.1 dBii(@ 910 MHz). Honeycomb tag manufactured by RSI Co. is suitable for the jewelry management than another other commercial near field tags. The tagging method and the tagging location of Honeycomb tag are suggested. In the suggested system, the maximum reading range is about 16 cm, and the zone with 100 % recognition rate is 10 cm from the radom of the reader antenna.

• Journal of Navigation and Port Research
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• v.33 no.1
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• pp.51-56
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• 2009

This paper presents the design of high sensitive/broadband tag antenna for Radio Frequency Identification (RFID) in Ultra High Frequency(UHF) band. A proposed tag antenna size is $60\;mm\;{\times}\;10\;mm\;{\times}\;1\;mm$. The resonant frequency is 910MHz and bandwidth is about 900 MHz at -10 dB below. The measured return loss and directional pattern have been confirmed a good agreement with the calculation results. The read range of proposed tag antenna with chip is observed about 6.5 m and proposed tag antenna has been observed an average 0.5 m for more than read range of the commercial tag antenna.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.8
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• pp.746-752
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• 2009

In this paper, we deal with the development of an optimal design program for a triple-band PTFA(Planar Inverted-F Antenna) of 433 MHz, 912 MHz and 2.45 GHz by using evolution strategy. Generally, the resonance frequency of the PIFA is determined by the width and length of a U-type slot used. However the resonance frequencies of the multiple U slots are varied by the mutual effect of the slots. Thus the optimal width and length of U-type slots are determined by using an optimal design program based on the evolution strategy. To achieve this, an interface program between a commercial EM analysis tool and the optimal design program is constructed for implementing the evolution strategy technique that seeks a global optimum of the objective function through the iterative design process consisting of variation and reproduction. The resonance frequencies of the triple-band PIFA yielded by the optimal design program are 430 MHz, 910.5 MHz and 2.458 GHz that show a good agreement to the design target values.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.5
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• pp.2325-2331
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• 2012

Planar square-spiral antenna using a strip conductor is proposed and analyzed for RFID system in UHF band operating from 860MHz to 960MHz. By varying the length of common line, detached distance, strip line-space, strip line-width and the number of spiral turn, the optimized antenna are designed and fabricated in compact size without a matching-stub between the input port of the proposed antenna and RFID tag chip. From the optimized results, the frequency bandwidth in VSWR<2 has covered 100MHz in the RFID UHF band. The antenna gain has obtained 3.5dBi at the center frequency of 910MHz and the desired beam pattern has shown directional pattern on elevation and azimuth angle. Therefore, the proposed antenna is suitable for practical RFID applications requiring various tag chips with the specific input impedance.