• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.9
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• pp.827-832
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• 2005

Dual band internal antennas were fabricated with Ag conducting paste of various preparation conditions and different print thickness by silk screen print. We have investigated microwave properties were compared Ag conducting paste antenna with copperplate antenna at 800 MHz and 1,800 MHz. Gain of Ag conducting paste antenna was improved when preparation conditions were the single size Ag particle, using dry type resin and high Ag containing percent. However, it was lower than that of copperplate antenna within $0.1\~2.0dBi$ at 800MHz. In addition, it was improved at 800MHz when thickness of Ag conducting paste was printed more than skin depth but it was held after critical print thickness. On the other hand, it was reached level of copperplate antenna at 1,800MHz.

• ETRI Journal
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• v.31 no.1
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• pp.74-76
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• 2009

A new feeding method for the circular polarization (CP) dielectric resonator antenna (DRA) is proposed in this letter. Two orthogonal modes (${TE^x}_{{\delta}11}$, ${TE^y}_{1{\delta}1$) of the rectangular DRA are excited by a $90^{\circ}$ phase difference of the differential and common modes currents of the proposed feeding structure. To demonstrate the good CP performance of the proposed method, a right-hand CP DRA for a global positioning system was designed. The impedance bandwidth of the proposed antenna for $S_{11}$ < -10 dB and 3 dB axial ratio bandwidth are about 5.4% and 1.95% at 1.57 GHz, respectively.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.519-523
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• 2003

In this paper, we proposed a new ultra wide-band(UWB) antenna for UWB communication applications. The proposed antenna is composed of a rectangular plate having two steps, single slot on plate and partial ground plane. This antennas operated from 3.2 to 13 GHz. Details of the proposed antenna design and measured results are presented discussed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.12
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• pp.1719-1724
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• 2013

In this paper, a size-reduction technique is presented for the RFID reader antenna working at two UHF bands. To tackle the problem of size increase in multi-band applications, two resonance paths are made to occur in one geometry with a single feed. While one resonance path is combined with the other, the entire geometry is determined to guarantee the resonance at the target frequencies through the dual-band input impedance matching. The antenna performance is predicted by the full-wave simulation, and the design method is verified by observing the good agreement between the simulated and measured results. At the two frequencies, the satisfactory return loss as well as the antenna efficiency and peak gain of the far-field pattern is obtained.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.1 s.24
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• pp.144-151
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• 2006

A rectangular loop antenna for S-band radar is proposed. The proposed loop antenna is the modified type of folded monopole antenna. The feeding line is coplanar stripline with $180^{\circ}$ phase difference for operating in odd mode. The proposed antenna showed return loss of -15.57dB at the center frequency and bandwidth of about 790MHz (> 25%) under the condition of VSWR < 2. The gains of single, 1x2, and 1x4 array loop antennas are 4.3, 7.0, and 10.2dBi, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.3
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• pp.250-256
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• 2002

In this paper, a broadband sleeve monopole antenna using a loading coil in sleeve is proposed. The center frequency of the proposed antenna is 1,990MHz. The antenna of the proposed structure has the same of the single sleeve monopole antenna, except for using the coil instead of the inner conductor in sleeve. As a result, it is found that the bandwidth is 1.239~2.154 GHz(above 53.9 %) for $S_{11}=-10\;d B$(VSWR<2), and the antenna impedance is good for a communication system and feeder which the impedance has 50 Ω.

• Journal of electromagnetic engineering and science
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• v.13 no.4
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• pp.214-223
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• 2013

This paper proposes a theoretical analysis of hidden device detection and a design of multiband circular polarization patch array antenna for non-linear junction detector system application. A good axial ratio of circular polarization patch antenna is realized by a new approach that employs inclined slots, two rectangular grooves and a truncated ground for the conventional antenna. A good axial ratio of the 1.5 dB lower is measured by having an asymmetric gap distance between the ground planes of the coplanar waveguide feeding structure. The common ground plane of the linear array has an optimum trapezoidal slot array to reduce the mutual coupling without increasing the distance between the radiators. The higher gain of about 1 dBi is realized by using the novel common ground structure. The measured return loss, gain, and axial ratio of the proposed single radiator, as well as the proposed array antennas, showed a good agreement with the simulated results.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.903-905
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• 2013

In this paper, we propose the CPW antenna with a spiral geometry for miniaturization. Widths of a spiral line are constant, and three stubs are added to broaden bandwidth. Proposed antenna is designed. Lengths and widths of three stubs are gradually changed and optimized.

• Journal of Communications and Networks
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• v.18 no.3
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• pp.320-326
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• 2016

In existing literature on multiple-input multiple-output (MIMO) relaying communication systems, antenna selection is often implemented by maximizing the channel capacity or the output single-to-noise ratio (SNR). In this paper, we propose an energy-efficient low-complexity antenna selection scheme for MIMO relaying communication systems. The proposed algorithm is based on beamforming and maximizing the Frobenius norm to jointly optimize the transmit power, number of active antennas, and antenna subsets at the source, relaying and destination. We maximize the energy efficiency between the link of source to relay and the link of relay to destination to obtain the maximum energy efficiency of the system, subject to the SNR constraint. Compared to existing antenna selection methods forMIMO relaying communication systems, simulation results demonstrate that the proposed method can save more power in term of energy efficiency, while having lower computational complexity.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.1
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• pp.117-124
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• 2001

In this paper, the design of a U-slot array antenna for PCS base station has been implemented and studied. The U-slot antenna is a single layer type with an antenna volume smaller but a bandwidth lager than the designs utilizing parasitic patches, which exceed 17 % bandwidth, for the probe fed case. Designed U-slot array antenna has stable radiation patterns and an average gain above 12 dB across the PCS frequency band. In this paper, through the designing of a U-slot array antenna, we have presented the availability for PCS base station antenna.