• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.81-82
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• 2016

In this paper, a design method for a compact log-periodic half-bow-tie dipole array antenna for an operation in UWB band is studied. The proposed antenna is miniaturized by using half-bow-tie shaped dipole elements instead of strip-type dipole elements, which are commonly used in general log-periodic dipole array antenna, and by reducing the element spacing. The effects of the flare angle of the half-bow-tie elements and the element spacing on input reflection coefficient and realized gain characteristics of the proposed log-periodic antenna are analyzed. The optimized antenna is designed on FR4 substrate, and it operates in the frequency band of 3.05-13.96 GHz for a VSWR < 2, which assures the operation in the UWB band.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.61-62
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• 2013

In this paper, a design method for a compact broadband planar dipole antenna fed by a microstrip (MS) line is studied. The proposed broadband dipole is optimized for terrestrial digital television (DTV) receiving. The dipole is fed by an MS line with 75-ohm characteristic impedance on an FR4 substrate and its size is $90mm{\times}180mm$. The dipole is modified to half bow-tie type for size reduction. A simplified balun is adopted for the impedance matching between the MS line and coplanar strip which feeds the dipole. The optimized dipole antenna for DTV band (470-806 MHz) is fabricated on an FR4 substrate and tested experimentally to verify the results of this study.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.6
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• pp.1057-1062
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• 2016

In this paper, a design method for a compact log-perio dic half-bow-tie dipole array antenna for an operation in a UWB band(3.1-10.6 GHz) is studied. The proposed antenna is miniaturized by using half-bow-tie shaped dipole elements instead of strip-type dipole elements, which are commonly used in a general log-periodic dipole array(LPDA) antenna, and by reducing the element spacing. The effects of the flare angle of the half-bow-tie elements and the spacing factor on input reflection coefficient and realized gain characteristics of the proposed log-periodic antenna are analyzed. The optimized antenna is fabricated on an FR4 substrate, and the experiment results show that the antenna has a frequency band of 2.95-11.31 GHz for a VSWR < 2, which assures the operation in the UWB band. In addition, the length and width of the proposed antenna are reduced to 32.1 % and 18.3 %, respectively, compared to the LPDA antenna.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.4
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• pp.1908-1914
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• 2013

In this paper, we introduce a design method for a broadband planar quasi-Yagi antenna (QYA) for terrestrial digital television (DTV) reception. The coplanar strip line which feeds the driver dipole is connected to a microstrip line and is terminated by short circuit. By appending a wide strip-type rectangular director at a location close to the driver dipole, broadband impedance matching and gain enhancement in a high frequency region are obtained. The gain characteristics in a low frequency region are improved by adding a reflector formed by a truncated ground plane. To reduce the antenna size, the strip-type dipole and reflector are modified to half bow-tie (V)-shaped elements. The effects of various parameters on the antenna characteristics are examined. An antenna, as a design example for the proposed antenna, is designed for the operation in the frequency band of 470-806 MHz for terrestrial DTV. The optimized antenna is fabricated on an FR4 substrate and the experimental results show that the antenna has a good performance such as a frequency band of 450-848 MHz for a VSWR < 2, gain > 4.1 dBi, and front-to-back ratio > 10.4 dB.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.12
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• pp.1212-1218
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• 2014

This paper proposes a planar bow-tie UWB antenna by modifying the ground patch of a reference bowtie-monopole antenna satisfying low band of UWB. The proposed antenna was implemented with five-angled ground patch to be operated in whole UWB band, while the reference antenna had a ground patch of half circle type. The measured return loss satisfies less than -10 dB in 3.1~10.6 GHz, except 4.9~5.8 GHz rejection band. The measured radiation pattern is almost the same with that of the monopole antenna. The radiation gain reduction is about 8 dB at rejection band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.12 s.115
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• pp.1199-1205
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• 2006

This paper proposes a wideband monopole antenna with improved band rejection characteristics by inserting two band notch slots with half wavelength in radiator. The designed antenna is composed of bow-tie patch fed electromagnetically with parasitic ground patch of a semicircular shape. We obtained band rejection filter-like characteristics by controlling coupling amounts between two horizontal resonance slots. Using this technique, we achieved the broad rejection bandwidth and improved skirt characteristics compared with only one notch slot. The measured bandwidth is from 2.7 GHz to 6.9 GHz for VSWR below 2.0 except the limited band of $4.96{\sim}5.51GHz$. This antenna shows a similar radiation pattern of the ideal monopole and the radiation gain reduction is more than $5{\sim}10dB$ on the x-z plane at rejection frequency.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.3
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• pp.497-502
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• 2014

In this paper, a design method for a broadband planar dipole antenna for terrestrial digital television (DTV) reception is studied. The dipole is modified to half bow-tie type for size reduction. The balun between feeding microstrip line and coplanar strip (CPS) line is implemented with a rectangular patch inserted along the center of the CPS line. The proposed antenna is the structure of dual resonances, one is due to the dipole and the other is due to the CPS line attached by the balun. The effects of various geometrical parameters on the antenna performance are examined, and the antenna is designed for terrestrial DTV band (470-806 MHz). The prototype antenna is fabricated on an FR4 substrate with a size of $95mm{\times}178mm$, and tested experimentally to verify the results of this study.

• 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.305-314
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• 2007

In this paper, we suggested a CPW-fed UWB antenna with uni-planar sectoral structure. The area where radiation device face ground is designed to have the shape of tapered slot based on exponential function. We modified a rectangular bow-tie dipole structure antenna and thus formed a multi-resonant mode. From this, we expanded the impedance bandwidth and made a feature satisfying VSWR of less than 2 between $3.1\sim10.6GHz$. The test result showed that the return loss less than -10 dB was met in the full-band UWB system and maximum gain of $0.9\sim3.1dB$ was made with the half-power beamwidth of $40.1\sim89.9^{\circ}$ on XY plane(Theta, $Phi=90^{\circ}$) and the full band. By using CPW-fed structure with no ground on the back of the substrate, the suggested antenna is easy to design and its miniaturization is also possible.

• Journal of Advanced Navigation Technology
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• v.26 no.1
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• pp.29-34
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• 2022

In this paper, the design of a triple dipole quasi-yagi antenna operating in the 2.45 GHz and 5 GHz wireless LAN frequency bands and the 3.5 GHz WiMAX frequency band was studied. The proposed quasi-Yagi antenna consists of three dipoles connected in series with a V-shaped ground plane. The longest half-bow-tie-shaped dipole resonates in the 2.45 GHz band, whereas the medium-length dipole resonates at 3.5 GHz. The shortest dipole resonates in the 5 GHz band. By adjusting the length and width of the dipoles and the spacings between the dipoles, a triple-band directional antenna operating in the 2.45 GHz, 3.5 GHz, and 5 GHz bands are designed, and fabricated on an FR4 substrate with a size of 45 mm × 55 mm. It was confirmed that the fabricated antenna operates in the designed triple bands of 2.32-2.57 GHz, 3.26-3.69 GHz, and 4.50-6.56 GHz for a voltage standing wave ratio less than 2. Gain is maintained above 3 dBi in the three bands.