• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.07a
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• pp.181-182
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• 2012

본 논문에서는 DVB-NGH 시스템에서 수직-수평 편파 안테나를 이용한 $2{\times}2$ MIMO SM 기법 중 두 안테나에 서로 다른 변조 차수를 가진 신호를 전송할 경우 비균등 전력을 이용하여 수신 성능을 향상시키는 기법을 제안한다. 이를 위해 기존의 MIMO SM 구조와 비교해 서로 다른 변조 차수를 가진 신호에 비균등 전력을 포함하는 송수신 시스템의 구조를 도입하였다. 전산실험 결과 LDPC 부호율이 각각 4/9, 2/3에서 비트오류율이 $10^{-4}$의 조건에서 0.2, 0.5 dB의 성능 향상이 있음을 확인할 수 있다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.5
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• pp.355-365
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• 2017

In this paper, we propose the design of a dual-band GPS antenna using in-direct feeding pads. The antenna consists of an upper patch for the GPS L1 band, a lower patch for the GPS L2 band, and two pads on the middle layer for feeding the two radiating patches. A hybrid chip coupler with a phase difference of $90^{\circ}$ is employed at the two feeding ports for achieving a broad circular polarization (CP) bandwidth. The proposed antenna shows bore-sight gains of 3.0 dBic(L1) and 5.1 dBic(L2), and axial ratios of 3.3 dB(L1) and 0.3 dB(L2) by measurement. The active element patterns of the fabricated array with 7 elements show bore-sight gains of -0.4 dBic (L1) and -2.4 dBic(L2), respectively. It proves that the proposed antenna structure is suitable for use in GPS array applications.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.1
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• pp.111-118
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• 2005

The shape of vertical pattern of base station antenna affects greatly quality of the communication of not only a service zone but also adjacent cells and then it is an important point to be considered in designing cell coverage. Currently type of vertical patterns to be applied to base station antenna are divided into five classes. In designing antenna, these five classes are applied solely or compositely according to the environment to be used antenna. In this paper, the dual polarized antenna for base station that is with a continuous electrical down tilting and with a shaped beam pattern, that an upper side lobe is suppressed and a lower null is filled, is designed and fabricated for synthesizing of the shape beant the pattern synthesis methods proposed by R. S. Elliott is used sequentially and for the electrical don tilting, the phased array theory is applied. Measured results show the down tilting range from 0° to 14°, the gain of Min. 13.3dBi and the upper side lobe of Max. -23dB. And we verified that upper side lobe is not to vary greatly and null filling performance is favorable overall.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.7
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• pp.707-712
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• 2008

In this paper, the sequentially rotated array(SRA) antenna with 256 elements applicable for satellite broadcasting reception was designed by arraying this triple(4+8+4 element) SRA antenna as a sub-array antenna. The structure of a triple SRA antenna is a combination of three coaxial shells composed with 4 elements of inner shell and 8 elements of middle shell and 4 elements of outer shell. In accordance with the optimum design rules for realizing a high gain antenna, the sequential array factors(M, P) of inner shell and outer shell have been chosen M=4 and P=1 and that of middle shell has been chosen M=8 and P=1. The results of the simulation and the measurement for the proposed triple(4+8+4 element) SRA antenna and the SRA antenna with 256 elements show good characteristics on the integration, bandwidth of the axial ratio and the cross-polarization, the gain respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.9
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• pp.800-807
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• 2016

In this paper, we study the characteristics of dual band microstip antenna with modified inset feeder and a single slot. The modified inset feeder consists of the vertical inset feeder placed in x direction and the horizontal one in y direction for shortening the total length of inset feeder. The optimun feeding position for good impedance matching at two resonant frequencies can be easily found by adjusting the horizontal inset distance. And Various frequency ratios can be simply obtained by the parameters of slot. The measurements for fabricated antenna prototypes are carried out for validation. The measured results show a tunable frequency ratio from 1.25 to 1.88 with the variation of slot parameters. It is worthwhile to point out that the radiation patterns are similar at both bands. and below -20.0 dB of cross polarization level at the E plane.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.3
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• pp.509-516
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• 1999

In this paper, it is designed a microstrip U-slotted patch antenna with double resonances to enhance the bandwidth. In the design of an U-slotted patch antenna, there are considered the input impedance, the width of patch, the total length of the slot, the height of foam, the position of the probe and the radius of feed pin. The broadband behavior of antenna can be obtained by adjusting the length and width of the slot. The radiation from the antenna is linear polarized with the E-paine parallel to the vertical slots and the H plane parallel to horizontal slot. The radiation pattern, impedance locus, and VSWR of the antenna are calculated using "ENSEMBLE" software, and compared with the experimental results. Experimental results show that the bandwidth for VSWR $\le$ 2:1 is about 28.6%, a directivity 14.18dBi at 6.040GHz. 6.040GHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.5
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• pp.748-754
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• 2000

A novel single feed wide band CP stacked microstrip antenna using crossed slots has been designed, fabricated and measured. For the single rediating element the designed 10dB return loss bandwidth is 34.5%99.45~13.54 GHz), 3dB axial ratio bandwidth is 18.7%(11.17~13.39GHz), and 6 dB gain bandwidth is 29%(10.21~13.64GHz). For the 2$\times$2 array designed using a sequential rotation method, the 10dB return loss bandwidth is 35.9%(9.69~13.94GHz), 3dB axial ratio bandwidth is 34.6GHz (9.93~14.03GHz), and 6dB gain bandwidth is 27.4%(10.35~13.6GHz). For the fabricated 8$\times$8 array antenna, the 10dB return loss bandwidth is 27.3%(10.17~13.41GHz), 3dB axial ratio bandwidth is 27.9GHz(10.1~13.4GHz), and the radiation pattern is good agreement with theory. This antenna can be used for broadband applications for communications or broadcasting in Ku band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.2
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• pp.125-130
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• 2011

In this paper, SIW-based $2{\times}4$ uniform array antenna with a sequentially fed 8-way power divider with an equal division characteristic is proposed for an application of X-band satellite communication. In particular, sequential feeding structures with a progressive phase difference of 90 degrees between the nearest elements have been suggested to protect the cancellation of electric fields due to the array alignments and to enhance the purity of RHCP(Right-Handed Circular Polarization). The obtained results according to the return loss bandwidth, RHCP antenna gain, axial ratio bandwidth are 760 MHz ranging from 7.90 to 8.66 GHz under the criterion of less than -10 dB, 14.3 dBic at 8.3 GHz, and 600 MHz from 8.15 to 8.75 GHz, respectively. In addition, it is observed that the equal-division characteristic of SIW-based 8-way power divider is approximately -9.2 dB in all ports.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.71-72
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• 2013

In this paper, a design method for a compact slot antenna for 5.8 GHz RFID band (5.725-5.875 GHz) is studied. The proposed slot antenna is size-reduced by bending both ends of the straight slot in "${\Gamma}$"-shape, and a rectangular feed patch is located inside the slot. The effects of slot length, location of feed patch, and width and length of feed patch on the antenna performance are examined. A prototype antenna with optimized parameters for 5.8 GHz band is fabricated on an FR4 substrate and tested experimentally. The experimental results show that the frequency band for a VSWR < 3 ranges 5.72-6.13 GHz (bandwidth 410 MHz), and it corresponds fairly well with the simulated band 5.64-5.97 GHz (bandwidth 330 MHz). The fabricated antenna shows good radiation performance such as maximum power density in both directions normal to the slot plane, and low cross-polarization level of < -20 dB.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.896-897
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• 2013

In recent years, logistics tracking Device using GSM & WCDMA to improve logistics efficiency are being extensively researched. The purpose of this paper is to examine the performance development antenna usable cargo container security transport. Antenna developed by study were optimized to match logistics environment apply to GSM & WCDMA dual frequency for monitering system. The measure of antenna have confirmation VSWR is 3:1 measured in return loss -10dB. Reliability of this antenna has been verified about GSM & WCDMA through test-operation between the south korea and Russia.