• Bulletin of the Society of Naval Architects of Korea
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• v.51 no.1
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• pp.13-16
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• 2014

• Electronics and Telecommunications Trends
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• v.6 no.3
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• pp.23-36
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• 1991

• Journal of Korea Far Infrared Association
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• s.16
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• pp.21-30
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• 2003

• Journal of Korea Far Infrared Association
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• s.17
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• pp.17-24
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• 2003

• Proceedings of the Korean Vacuum Society Conference
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• 1992.07a
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• pp.75-76
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• 1992

• 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.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.11 s.114
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• pp.1082-1088
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• 2006

A turnstile antenna using the parasitic monopole has been developed for STSAT-2 TT&C application. The antenna consists of two radiating elements; a bow-tie dipole and a parasitic monopole. The bow-tie dipole is main radiating element, used a bow-tie structure for bandwidth improvement and size reduction. The parasitic monopole improved beamwidth and axial ratio. The input impedance of the antenna is about 50 ohm without a matching circuit. The proposed antenna has beamwidth of $>140^{\circ}$, axial ratio of < 3 dB and VSWR of < 1.5 in the band of $2.075{\sim}2.282GHz$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1445-1450
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• 2013

In this paper, a broadband series-fed bow-tie dipole pair (SBDP) antenna operating in the band of 1.7-2.7 GHz for mobile communication base station applications is proposed. The proposed antenna uses bow-tie-shaped dipole elements instead of straight strip dipole ones used in a conventional series-fed dipole pair (SDP) antenna. The simulation results show that the lowest operating frequency is shifted toward lower frequency as the flare angle increases, and so the lengths of the bow-tie dipole elements can be reduced in proportion to the frequency shift toward lower frequency. An SBDP antenna with a flare angle of 10 degrees is fabricated on an FR4 substrate (dielectric constant = 4.4 and thickness = 1.6 mm) and total width of the fabricated antenna is reduced by 10% compared to that of the conventional SDP antenna. The measured impedance bandwidth for voltage standing wave ratio (VSWR) < 2 is 48.8% (1.69-2.78 GHz), gain is 5.8-6.3 dBi, and the front-to-back ratio (FBR) is 14-17 dB.

• Journal of the Korean Orthopaedic Association
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• v.55 no.1
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• pp.85-89
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• 2020

Bow hunter's syndrome is a rare disease that shows the symptoms of vertebrobasilar insufficiency resulting from a dynamic obstruction or stenosis of the vertebral arteries during neck movement. This paper reports a case of a 59-year-old male who visited the emergency room with diplopia, tinnitus, and gait disturbance. Magnetic resonance imaging and angiography revealed a multiple cerebellar infarct, total obstruction of the right vertebral artery, and dynamic obstruction of the left vertebral artery during neck extension. As the infarction worsened, a thrombectomy was done. Posterior decompression and fusion at C5-6 were performed for the left vertebral artery. The left vertebral arterial patency was confirmed by intraoperative and postoperative angiography. No recurrence of the symptoms was observed for six months after surgery. Physicians need to pay attention to the diagnosis of vertebrobasilar insufficiency caused by an obstruction of the vertebral arteries during neck extension in cervical instability patients.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.3
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• pp.300-305
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• 2012

In this paper, a miniaturized bow-tie monopole UWB antenna with band rejection characteristic is proposed. To miniaturize the proposed antenna, a perfect magnetic wall(PMW) condition is applied to primitive bow-tie monopole antenna. An uneven ground patch, a tapered feeding structure and a edge-chopped main patch are adapted for impedance matching. A quater-lambda slot resonator is inserted at main patch to prevent interference in UWB band from another band. The proposed antenna is fabricated on Taconic RF60-A substrate with relative permittivity of 6.15. The size of the proposed antenna is $30.0{\times}39.7mm^2$, which is only 45 % of the conventional bow-tie monopole antenna. The proposed antenna covers full UWB band with return losses less than -10 dB and has band stop characteristic in 5 GHz WLAN band. The maximum gains are within -1.0~5.0 dBi, the group delay variations are within 1.0 ns and the radiation patterns show directivity characteristics in x-y plane.