• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.8
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• pp.15-27
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• 2008

In this paper, an EBG(Electromagnetic BandGap) resonator antenna with a stripline type FSS(Frequency Selective Surface) superstrate for PCS-band base station antennas is proposed. The characteristics of resonant frequency and -3dB bandwidth of a unit cell of a superstrate are first analyzed by varing several design parameters such as a strip width and a unit cell width in order to design an EBG resonator antenna satisfying the required antenna gain and bandwidth for PCS-band base station antennas. Among various unit cell shapes, strip dipole and stripline are considered and their characteristics are compared. It was found that a resonant length of the EBG resonator antenna becomes smaller when the stripline shape is used and the control of the bandwidth is also much easier. By using the unit cell simulation results, planar and cylindrical EBG resonator antennas at PCS-band are designed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.3
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• pp.273-279
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• 2009

In this paper, an antenna which has dipole-like radiation pattern and low profile is proposed. The antenna is composed of four elements slot array based on L-shaped 0.43 $\lambda_g$ slot element. It presents a omni-directional radiation patter in the azimuth plane and has a null toward broad-side direction. In the design, a small mono-pole antenna which acts as a large capacitance element, combined with the partially removed ground plane by four L-shaped slots. As a result, these structure act as a LC resonator for radiation. The measured result shows, the impedance bandwidth(VSWR$\leq$2) of the proposed antenna is 60 MHz(2.35$\sim$2.41 GHz). The measured maximum radiation gain and efficiency of proposed antenna is 0.02 dBi, 56.7 % at center frequency 2.38 GHz, respectively. The proposed antenna can be applied to wireless tan access point system.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.6
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• pp.43-55
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• 2013

In this paper, we propose a cylindrical active phased array antenna of Beam Steering Characteristics in the horizontal plane(H-plane) and vertical plane(E-Plane) on the cylinder form array structure. We design the bent dipole antenna of the cylindrical array structure adapted excellent mutual-coupling characteristics, designed and manufactured the cylindrical array antennas and power combiner/divider unit for power dividing and combining on the antenna. The radiating elements array spacing of Cylindrical array antenna were determined to avoid grating lobes at half power beam steering. Beam steering of the antenna was implemented with 6-bit phase shifter in the transceiver and have been designed based on the characteristics the antenna beam steering at -24 degrees to 24 degrees horizontal, vertical 0 degrees to 36 degrees beam steering. A cylindrical active phased array antenna that produced for verification the performance of the antenna are measured radiation characteristics in accordance with beam steering at L-Band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.8
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• pp.913-921
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• 2007

In this paper, we propose a novel small antenna for direction finding applications. The proposed antenna employs a skirt type disk to eliminate the radiation null on the broad-side direction in the high frequency range. Additionally, the multi-section matching stub is used for impedance matching in the low frequency range, The size of the proposed antenna is reduced as a half of the 60cm dipole which has a same resonance frequency of 200MHz. The antenna maintains a donut shape radiation pattern with a broad beam width for a wide range of frequency while the 60cm dipole shows radiation nulls on the broad-side direction and the high side-lobe level from 700MHz to 1,300MHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.4
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• pp.270-276
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• 2018

Fifth-generation communications are approaching, and they will require broadband antennas that include the existing LTE frequency band (1.7 GHz to 2.7 GHz) and the newly allocated frequency band (3.4 GHz to 3.7 GHz). Many kinds of antennas satisfy the required broadband characteristics, including the dual-element folded dipole antenna proposed in this paper. A zigzag line was used to make the antenna more compact. This was accomplished by reducing the physical length while maintaining the electrical length. To validate the proposed antenna, a prototype was fabricated using PCB (${\epsilon}_r$:4.4, Height: 1.6 mm) and its performance was evaluated. Results obtained by simulation and experiment showed good agreement.

• Journal of Navigation and Port Research
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• v.32 no.10
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• pp.805-811
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• 2008

This paper presents a design of RFID(Radio Frequency Identification) tag antenna which is available for a vehicle's side mirror and directivity characteristics by mr body. The proposed Tag antenna is designed symmetrical structure to improve the broad bandwidth characteristic and the readable range. A proposed tag antenna($30\;mm{\times}24\;mm{\times}1\;mm$) has resonant frequency at 910 MHz and bandwidth is 780 MHz ($540\;MHz{\sim}1320\;MHz$). The chip impedance is the 16 - $j131\;{\Omega}$ and the complex conjugate impedance of commercial chip has been used for tag antenna design. In order to evaluate effects of tag antenna for side view mirror's permittivity as well as car body(conductor), radiation pattern characteristics and readable range have been calculated and measured. The optimized position for a vehicle's RFID system has been observed in the inside of a side mirror and the calculated results show good agreement with the measured results.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.559-562
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• 2010

This paper deals with characteristic of the several environment of multipath using antennas. The transmit antenna is ${\lambda}$/4 dipole and receive antenna is inductance loaded antenna. We investigate the significance of a solution of interference by multipath by comparing BER(Bit-Error-Rate) in multipath environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.59-60
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• 2017

In this paper, the bandwidth and gain enhancement of a series-fed dipole pair antenna (SDPA) using a modified balun., a director, and two parasitic patches is studied. The proposed SDPA consists of two strip dipoles with different lengths, a ground reflector, which are connected through a coplanar strip line, a director, and two parasitic patches. The modified balun is used to increase the bandwidth, whereas the director and two parasitic patches are appended to the SDPA to enhance the gain in the middle and high frequency band. A prototype of the proposed SDPA is fabricated on an FR4 substrate, and the experimental results show that the antenna has a frequency band of 1.56-3.10 GHz for a VSWR < 2, and measured gain maintains over 7 dBi in the frequency range of 1.55-3.00 GHz.

• Journal of the Korea Concrete Institute
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• v.17 no.2 s.86
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• pp.221-227
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• 2005

The presence of voids behind tunnel linings is very likely to result in settlement or structural collapse. One proposed method of detecting such voids by non-destructive method is radar. More than effectively judging the existence of voids behind tunnel linings, this study aims to develop the analysis algorithm of radar capable of estimation of the shape of specific voids. To acquire directional information and estimate the shape of three-dimensional voids, the radar of three-dipole antenna type is used. As a foundation to this ongoing research, an investigation of microwave polarization methods using three-dipole antenna carried out with various void orientations and void geometries. As a result, it is clarified that the response of four microwave polarization modes depends on void geometry and thus there is a possibility of identifying the geometry and orientation (the shape) of specific voids using radar of three-dipole antenna type.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.9
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• pp.1030-1036
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• 2010

This paper proposes a simulation design for feeding probe with the CMM(Cylindrical Magneto Material) structure for broad bandwidth of a dipole type antenna. In order to ensure low frequency bandwidth, the magnetic material with high relative permeability was considered in design calculation. It was confirmed that the broad bandwidth was independent on the relative permeability value and depended on the control of distance($r_m$) between magnetic material and feeding probe, and of magnetic material thickness($t_m$). Furthermore, an antenna size with the CMM was miniaturized about 18 % comparison with its size without the CMM.