• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.5
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• pp.567-574
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• 2014

In this paper, a VHF antenna with monopole structure is designed and fabricated for marine wireless communication applications. The proposed antenna is based on a monopole design, and composed of circular ring and meander structure for VHF operation which cover VHF frequency bands. To obtain the optimized parameters, we used the simulator, Ansoft's High Frequency Structure Simulator(HFSS) and found the parameters that greatly effect antenna characteristics. Using the obtained parameters, the antenna is fabricated. The experiment results demonstrated that the proposed antenna satisfied the -10 dB impedance bandwidth requirement while covering the VHF bands. And measured characteristics of gain and radiation patterns are obtained for operating bands.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.1
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• pp.127-134
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• 2014

X-Band taper slot-typed active phased array antenna is studied and designed. Through the simulated and measured performances, it is confirmed that both of active reflection coefficient and active radiation pattern of the designed phased array antenna are agreed well with those of the prototype manufactured one. From this study, the proposed antenna structure is matched to the design target of characteristics of antenna's broadband beam.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.1
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• pp.1-9
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• 2014

In this paper, a reconfigurable polarization patch antenna that uses a Y-shaped feed is proposed. The proposed antenna consists of a square patch, a Y-shaped feeding structure, a PIN diode, and a bias circuit for diode operation. The structural symmetry/asymmetry of the feeding structure is determined by the on/off operation of the PIN diode that inserted into the side of one of the lines of the Y-shaped feeding structure. For the proposed reconfigurable antenna, the two microstrip lines of the feeding structure have the same length when the PIN diode operates in the on state, and the antenna exhibits linear polarization(LP). On the other hand, when the PIN diode operates in the off state, the length of one side line of the feeding structure is relatively shorter than that of the other line. Therefore, the antenna exhibits circular polarization(CP). From the measurement results, it is found that the proposed antenna exhibits good impedance matching and axial ratio. In addition, polarization switching can be easily achieved in the same operating band.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.125-129
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• 2014

In this paper, design and fabrication of the GPS receiving antenna using Hilbert curve fractal structure was proposed. The size of the antenna was miniaturized by transforming dipole structure into monopole structure because its size increases if Hilbert curve fractal dipole structure is used. To use a Hilbert curve structure, the current directions of the radiator were made oppositely each other. The size of the antenna is $10{\times}10{\times}0.8[mm]$, the line width is 0.25[mm]. The resonant frequency is 1.58[GHz] and its range is 1.52[GHz] ~ 1.65[GHz]. Frequency bandwidth is 130[MHz]. Antenna maximum gain is 3.09[dBi].

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5447-5451
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• 2012

This paper presents a pattern-switchable microstrip patch antenna with loop structure. The loop structure for switchable radiation beam pattern is connected with feeding line of the microstrip patch antenna. As changing switch on/off state, the radiation beam pattern can be changed. The target frequency is 2.4 GHz and maximum radiation gain is 3.2dBi. The proposed antenna is useful for diversity antenna and smart antenna in modern wireless communication including MIMO (Multi-Input Multi-Output) and WLAN system. The sizes of the rectangular patch and the ground plane are $28mm{\times}28mm$ and $40mm{\times}50mm$, respectively. The simulation and experimental results show that the antenna radiation pattern can be changed with switch on/off configuration.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.3 s.118
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• pp.323-333
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• 2007

In this paper, a new MDAS-DR antenna structure designed to efficiently shape a flat-topped radiation pattern is proposed. The antenna structure is composed of a stacked micro-strip patch exciter and a multi-layered disk array structure(MDAS) surrounded by a dielectric ring. The MDAS, which was supplied by a stacked microstrip patch exciter with radiating power, can form a flat-topped radiation pattern in a far field by a mutual interaction with the surrounding dielectric ring. Therefore, the design parameters of the dielectric ring and the MDAS structure are important design parameters for shaping a flat-topped radiation pattern. The proposed antenna used twelve multi-layered disk array elements and a Teflon material with a dielectric constant of 2.05. An antenna operated at 10 GHz$(9.6\sim10.4\;GHz)$ was designed in order to verify the effectiveness of the proposed antenna structure. The commercial simulator of CST Microwave $Studio^{TM}$, which was adapted to a 3-D antenna structure analysis, was used for the simulation. The antenna breadboard was also fabricated and its electrical performance was measured in an anechoic antenna chamber. The measured results of the antenna breadboard with a flat-topped radiation pattern were found to be in good agreement with the simulated one. The MDAS-DR antenna gain measured at 10 GHz was 11.18 dBi, and the MDAS-DR antenna was capable of shaping a good flat-topped radiation pattern with a beam-width of about $40^{\circ}$, at least within a fractional bandwidth of 8.0 %.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.145-150
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• 2016

In this paper, we proposes a DTV indoor receiving antenna with a gap sleeve monopole structure. The proposed antenna uses a basic structure of a sleeve monopole and gap sleeve. To optimize antenna, we have adjusted the gap between monopole and sleeve, the gap between sleeve and ground. In order to confirm the property of antenna parameters, it was used a commercial software, HFSS. For the antenna fabrication, a FR4 dielectric substrate which has a dielectric constant of 4.7 was used. The size of the antenna was $213mm{\times}40mm{\times}1.6mm$. Frequency band of the fabricated antenna was 432MHz ~ 827MHz, and the bandwidth was 395MHz. The maximum gain of the antenna was 2.19dBi. Consequently, it was confirmed the possibility of practical application of the DTV indoor receiving antenna with a gap sleeve monopole structure.

• International journal of advanced smart convergence
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• v.1 no.1
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• pp.1-5
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• 2012

We propose a structure for a multiple input multiple output antenna which has no space for isolation. The antenna operates in a frequency range of 2.4-2.48 GHz and can achieve a high channel capability as a Bluetooth antenna. The MIMO antenna consists of two planar inverted F antennas with symmetric structure. We designed the proposed antenna using HFSS simulator, and we designed the fabricated antenna using PCB fabricator. The MIMO antenna's isolation $S_{21}{\leq}-10dB$ and reflection coefficient $S_{11}{\leq}-20dB$. The proposed antenna's specification satisfies Bluetooth antenna's criteria and has more space than the existing MIMO antennas, which have space for isolation.

• Journal of IKEEE
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• v.23 no.3
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• pp.1100-1103
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• 2019

This paper presents the design method of a planar sleeve monopole antenna on PCB, which has wider bandwidth compared to that of the conventional sleeve monopole antenna, by showing the fact that the sleeve of the conventional antenna can be simplified in structure. The designed and fabricated planar sleeve monopole antenna's structure is very simple, with a monopole adjacent to a small square sleeve on FR4 PCB. The antenna shows 46% wider bandwidth compared to the corresponding 3-dimensional one with nearly omni-directional radiation property.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.05a
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• pp.77-80
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• 2002

Thermal analysis has been performed to evaluate the thermal effect on composite antenna (Ka-band) structure in space environment. The concepts of thermal control are also presented to maintain the antenna components within respective temperature limits. A steady-state algorithm of I-DEAS' thermal analysis software was utilized to predict both maximum and minimum temperature, maximum gradient temperature, and temperature distribution on each antenna component.