• 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.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.7 s.110
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• pp.605-614
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• 2006

In this paper, a 3D structure skimmer-shaped circular microstrip antenna is designed, the ends of whose both sides are made as DC(Depressed Carving part) applying perturbation effect to reduce the patch size of microstrip antenna operating at design frequency 1.575 GHz. The result shows its return loss, - 10 dB bandwidth, gain, - 3 dB beamwidth E, H-plane are -26.59 dB, 65 MHz(4.13 %), 4.66 dBd, $79^{\circ},\;87^{\circ}$ respectively. The diameter of the antenna is 85 mm, which is 12.4 % reduced compared to the size(97 mm) of general microstrip patch antenna. Therefore its area reduction is 23.2 %. Furthermore, a linear and circular polarized baseball-shaped circular microstrip antenna is designed to minimize the patch size of the antenna. This structure of antenna operating at the design frequency 1.575 GHz is applied with the optimum RC(Raised Carving part) & DC ratio and an asymptotic line angle. In case of linear polarized baseball-shaped circular microstrip antenna, the patch size of the antenna is 74 mm, which is 41.8 % area reduction compared to general microstrip patch antenna. In case of circular polarized baseball-shaped circular microstrip antenna, the diameter of patch is 82 mm, which is 28.5 % area reduction compare to general microstrip patch antenna linear polarized. We have verified that the perturbation effect can be applied to minimize the circular microstrip antenna.

• ETRI Journal
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• v.34 no.1
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• pp.118-121
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• 2012

In this letter, a miniaturized log-periodic dipole array (LPDA) antenna operating from 1 GHz to 6 GHz is proposed for portable direction finding applications. To reduce the lateral size of an LPDA antenna, bow-tie elements and a top-loading technique are utilized and spacing factor is decreased to reduce the spacing between the LPDA elements. The proposed miniaturized LPDA antenna has the measured gain and front-to-back ratio ranging from 1.2 dBi to 3 dBi and from 7 dB to 22 dB, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.6
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• pp.1194-1199
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• 2006

In this paper, small printed antennas for MIMO applications are presented. The proposed antennas are based on PIFA structure which is a popular approach for miniaturization. The obtained antenna operates in IEEE802.11a band (5.15-5.35GHz) and has a planar structure which can be adopted for various potable applications. According to our simulation results, prototype antennas are manufactured and the isolation among the antenna elements are measured for MIMO applications. And we suggest a technique to improve isolation by adding a $\lambda$/4 slit between two antennas and investigate the results.

• International journal of advanced smart convergence
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• v.11 no.4
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• pp.41-46
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• 2022

This study is a Ku-band array antenna for the manufacture of low-orbit satellite communication terminals, designed to have miniaturization, high gain, and wide beam width. The transmission of low-orbit satellite communication has a right-rotating circularly polarized wave, and the reception has a left-rotating circularly polarized wave. The 4×8 array antenna was separated for transmission and reception, and it was combined with the RF circuit part of the transmitter and receiver, and was terminated in the form of a waveguide for RF signal impedance matching in the form of a transition from the microstrip line to the waveguide. The 30° beam width of the receiver maximum gain of 19 dBi and the 29° beam width of the transmitter maximum gain of 18 dBi are shown. Through this antenna configuration, the system was configured to suit the low-orbit satellite transmission/reception characteristics.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.5 s.108
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• pp.476-482
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• 2006

In this paper, a multimode feed horn antenna is suggested for a high power microwave(HPM) antenna system. The proposed HPM feed horn antenna which is connected with a mode converter is located between source and reflector antenna. A multimode feed horn antenna which has reduced -25 dB beamwidth is designed and fabricated for miniaturization of reflector antenna because -25 dB beamwidth which is determined by considering spillover of feed horn antenna decides a size of reflector in case of HPM. As a result, feed system which uses the multimode feed horn antenna has high gain about 27 dBi and return loss is less than -22 dB at 10 GHz. The measured -25 dB beamwidths of the radiation pattern at vertical, horizontal-plane equal to $20.24^{\circ},\;28.92^{\circ}$ which is less than about $10^{\circ}$ beamwidth of conventional feed system. Thus the suggested feed hem antenna is suitable to feed horn for miniaturization of HPM antenna system.

• Journal of Satellite, Information and Communications
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• v.12 no.1
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• pp.72-75
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• 2017

In this paper, we design the circular slits in the parch antenna for size reduction and high gain working at 900 MHz. Modifying the rectangular type patch, we decrease the antenna real-estate, leading to antenna miniaturization with added circular slits in itself. The antenna is tuned for under -30 dB return loss by adjusting the number of circular slits and their radii, and its design is performed for the maxim bean pattern of 4 dBi gain. Compared with the antenna without circular slits, the designed antenna shows 20 MHz downward shift of frequency, proving that the size reduction is achieved with this antenna design.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.158-158
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• 2008

In general, a wireless communication device has employed a whip antenna or a stubby antenna. Recently, wireless communication device is increasingly employing an embedded antenna, Intenna, for the sake of miniaturization. Further, it may employ both external and embedded antennas. Examples of the embedded antenna include a multi-band monopole antenna, which radiates uniformly in all directions when viewed from above, and a planar inverted F antenna (PIFA), which is a variation of the monopole antenna. However, since the conventional antenna is mounted in a finished state on the mobile communication terminal, there is a limitation of space required for providing the antenna. According to the present study, there is provided an Intenna that is deposited on a front or back case of the mobile communication terminal by a sputtering method. Accordingly, it is possible to overcome a limitation of space required for providing the Intenna and to improve the performance of the Intenna formed on the front or back case of the mobile communication terminal.

• Journal of Advanced Navigation Technology
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• v.16 no.1
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• pp.35-40
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• 2012

In this paper, we present the size reduction method of HF whip antenna for ship communication. To reduce the size of the HF whip, the end part of linear whip is modified to helical type. We designed the whip antenna with 60% size of the commercial whip antenna and carried out communication experiments using the commercial and the designed whip antennas. From the experimental results, we found that the proposed whip antenna can replace the commercial whip antenna for ship communication.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.5 s.96
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• pp.501-510
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• 2005

In this paper, the miniaturized linear and circular polarization microstrip antennas are designed and fabricated at the resonant frequency of 1.575 GHz. To miniaturize the microstrip patch antenna(MPA), the 'L' type plates are attached under the rectangular microstrip patch. In case of the linear polarization, the size of the microstrip antenna attached the 14 plates is reduced to $67.9\%(47mm{\times}47mm)$ compared with general $MPA(83mm{\times}83mm)$. The return loss and -10 dB bandwidth are -34.4 dB and 49 $MHz(3.1\%)$. And the radiation pattern is broad through the size reduction of the patch. Also in case of the circular polarization, the size of the microstrip antenna with 13 plates is reduced to $54.6\%(53mm{\times}54mm)$ compared with the general $MPA(76mm{\times}83mm)$. The axial ratio is 1.37dB at 1.575 GHz, the 2 dB axial ratio bandwidth is 14 $MHz(0.8\%)$. As that result, we could confirm that 3-dimensional structure with attached 'L' shaped plate is proper form for the miniaturization of linear and circular polarization microstrip antenna.