• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.8
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• pp.718-729
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• 2015

A S / X dual broad band patch antenna with shared aperture structure is fabricated. A $2{\times}2$ perforated patch is used for S-band operation and a $2{\times}2$ patch antenna array is integrated in the $2{\times}2$ perforation for X-band operation. The measurement results of a S / X dual broad band patch antenna with shared aperture structure show the broad band characteristics larger than 20 % in both bands.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.9
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• pp.1030-1036
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• 2010

This paper proposes a simulation design for feeding probe with the CMM(Cylindrical Magneto Material) structure for broad bandwidth of a dipole type antenna. In order to ensure low frequency bandwidth, the magnetic material with high relative permeability was considered in design calculation. It was confirmed that the broad bandwidth was independent on the relative permeability value and depended on the control of distance($r_m$) between magnetic material and feeding probe, and of magnetic material thickness($t_m$). Furthermore, an antenna size with the CMM was miniaturized about 18 % comparison with its size without the CMM.

• Journal of electromagnetic engineering and science
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• v.17 no.4
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• pp.202-207
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• 2017

This paper presents the performance of a planar, low-profile, and wide-gain-bandwidth leaky-wave slit antenna in different thickness values of high-permittivity gallium arsenide substrates at terahertz frequencies. The proposed antenna designs consisted of a periodic array of $5{\times}5$ metallic square patches and a planar feeding structure. The patch array was printed on the top side of the substrate, and the feeding structure, which is an open-ended leaky-wave slot line, was etched on the bottom side of the substrate. The antenna performed as a Fabry-Perot cavity antenna at high thickness levels ($H=160{\mu}m$ and $H=80{\mu}m$), thus exhibiting high gain but a narrow gain bandwidth. At low thickness levels ($H=40{\mu}m$ and $H=20{\mu}m$), it performed as a metasurface antenna and showed wide-gain-bandwidth characteristics with a low gain value. Aside from the advantage of achieving useful characteristics for different antennas by just changing the substrate thickness, the proposed antenna design exhibited a low profile, easy integration into circuit boards, and excellent low-cost mass production suitability.

• Journal of Advanced Navigation Technology
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• v.14 no.6
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• pp.817-823
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• 2010

Design of IPI feeding structure affecting the antenna gain improvement of mobile phone was investigated. IPI feeder which based on the T matching theory increase line current for internal antenna such as IFA. So IPI feeder makes higher radiation resistance, and also increases the gain with increasing radiation efficiency. To verify IPI feeding effect, feeder is applied to conventional CDMA/DCS dual band IFA. Measurement shows that IPI-IFA has 0.5 ~ 1.4[dBi] higher gain than conventional IFA at CDMA/DCS band. Resonant frequency did not change.

• Journal of electromagnetic engineering and science
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• v.17 no.4
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• pp.233-237
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• 2017

In this paper, a dual-band high frequency (HF) and ultra-high frequency (UHF) radio-frequency identification (RFID) tag antenna is presented that operates in the 13.56 MHz band as well as in the 920 MHz band. A spiral coil along the edges of the antenna substrate is designed to handle the HF band, and a novel meander open complementary split ring resonator (MOCSRR) dipole antenna is utilized to generate the UHF band. The dual-band antenna is supported by a single-feeding port for mono-chip RFID applications. The antenna is fabricated using an FR4 substrate to verify theoretical and simulation designs, and it has compact dimensions of $80mm{\times}40mm{\times}0.8mm$. The proposed antenna also has an omnidirectional characteristic with a gain of approximately 1 dBi.

• 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.298-304
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• 2007

In this paper, the antenna which has a multiband operation (GSM850, EGSM, DCS1800, USPCS, W-CDMA) is proposed. This antenna was designed by the commercial software HFSS 3-D EM simulator, and it is organized by using a meander branch structure which has a via and lines on FR-4$(\varepsilon_r=4.4)$ substrate. Especially, it has a gap feeding structure which makes good operation at overall bandwidth. The designed antenna is manufactured by PCB processing, and measured by using a network analyzer and a test chamber. The manufactured antenna with the dimension of 8 mm width, 20 mm height and 3.2 mm thickness is able to applied as an internal antenna for multiband mobile phones.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.2058-2060
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• 2004

In this paper, circular polarized antennas of Tx 30GHz and Rx 20GHz are implemented in LTCC process. Tx antenna has a circular patch structure and Rx antenna has a ring patch structure. The feeding line of Tx antenna is placed in the center hole of Rx ring patch antenna which is printed under Tx circular patch antenna layer. It makes antenna size smaller. Tx antenna's return loss in under -10dB level from 30GHz to 31GHz and Rx antenna is under -10 dB from 20GHz to 21GHz. The isolation between two antennas is less than -20dB. Axial ratio is less than 3dB though out each band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.3 s.106
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• pp.280-286
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• 2006

Determination method of optimum feeding point for the PIFA type internal antenna for the mobile phone handset was studied. Fundamental theory is that radiated gain is basically depended upon the electric field strength between PIFA conductor and ground plane. Feeding point, slit configuration, material and structure of carrier are main factors fur the PIFA performances. It is shown that maximum electric field strengths of other feeding points decrease in -2dB to -10 dB than optimum point. Ansoft HFSS EM simulator was applied to determine the best feeding point for 2 models of Samsung Electronics mobile phone handset.

• Journal of electromagnetic engineering and science
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• v.15 no.2
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• pp.115-119
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• 2015

This paper proposes a reconfigurable square-patch antenna with polarization diversity. The proposed antenna consists of a square radiating patch and a Y-shaped feed structure with two PIN diodes. The shape of the feed structure can be changed by adjusting the bias states of the two PIN diodes, which helps switch between two orthogonal linear polarizations. The polarization diversity characteristic is validated by the simulated current distribution and the measured radiation pattern.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.8
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• pp.1159-1163
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• 2012

In this paper, a new method is suggested to reduce the size of a wide-band array antenna. The power-divider for the feeding structure is made compact as ${\lambda}/8$ with the help of a novel Metamaterial UWB bandpass filter. This power divider is clearly different from others in that the proposed design uses microstrip structured Composite Right and Left-Handed (CRLH) filters, while others use two dielectric layers or long tapered transmission lines. In order to validate the proposed design method, the circuit and full-wave simulated results of the power divider with the Metamaterial UWB filters are compared to each other, and the Metamaterial properties of the structure are shown with the electric field at the ZOR and dispersion diagram. Furthermore, the antenna performance of the fabricated antenna with the power divider is measured and compared with the prediction. Also, the size reduction effect by the proposed scheme is addressed.