• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 I
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• pp.609-612
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• 2003

For combating multipath fading in wireless radio environment, diversity schemes is useful. In this paper, for performance improvement of polarization diversity system, we analyzed a two-branch polarization diversity at the receiving end of a mobile link when the transmitter emits a circularly polarized wave. And In order to calculate the correlation coefficient considering the XPD(cross polarization discrimination) between the received signals for the two diversity branches, a simple theoretical model of circular polarization diversity is adopted and calculate correlation coefficient. From the analysis results, it is seen that the correlation coefficient of circular polarization diversity evaluated by the XPD is less than that of vertical polarization diversity. And also, we designed and fabricated circular polarization diversity system with microstrip antenna. we analyzed data measured in indoor NLOS environment using fabricated circular polarization diversity system. From the measurement results, it is clearly seen that the diversity effect of circular polarization diversity system is higher 3dB than vertical polarization diversity system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권4호
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• pp.1292-1306
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• 2014

This paper proposes a space-polarization division multiple access (SPDMA) system that has limited feedback channels. The system simultaneously serves data streams to multiple mobile users through dual-polarized antenna arrays, by using pre-determined sets of precoding vectors that are orthogonal in both space and polarization domains. To this end, a codebook whose elements are sets of the precoding vectors is systematically designed based on the discrete Fourier transform (DFT) matrix and considering the power imbalance of polarized channels. Throughput of the SPDMA system is evaluated and compared to that of space division multiple access (SDMA) system, according to the various parameters including cross polarization discrimination (XPD). The results show that the throughput of SPDMA system outperforms that of SDMA in the environments of high XPD with many mobile users.

• ETRI Journal
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• 제36권1호
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• pp.155-158
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• 2014

This letter presents an antenna design method for an orthogonally-polarized dual antenna for use in mobile stations (MSs) and includes a verification method for improving the link-level throughput performance of an MS that uses a proposed multiple-input multiple-output antenna. The link-level throughput performance of an MS is strongly related to the correlation between antenna branches, which is determined by the cross polarization discrimination of the second branch antenna, both numerically and experimentally.

• 한국통신학회논문지
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• 제30권9A호
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• pp.788-794
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• 2005

In this paper, we focus on the potential of dual polarized antennas in mobile system. thus, this paper designs exact dual polarized channel with Spatial Channel Model (SCM) and investigates the performance for certain environment. Using proposed the channel model; we know estimates of the channel capacity as a function of cross polarization discrimination (XPD) and spatial fading correlation. It is important that the MIMO channel matrix consists of Kronecker product dividable spatial and polarized channel. Through the channel characteristics, we propose an algorithm for the adaptation of transmit antenna configuration to time varying propagation environments. The optimal active transmit antenna subset is determined with equal power allocated to the active transmit antennas, assuming no feedback information on types of the selected antennas. We first consider a heuristic decision strategy in which the optimal active transmit antenna subset and its system capacity are determined such that the transmission data rate is maximized among all possible types. This paper then proposes singular values decision procedure consisting of Kronecker product with spatial and polarize channel. This method of singular value decision, which the first channel environments is determined using singular values of spatial channel part which is made of environment parameters and distance between antennas. level of correlation. Then we will select antenna which have various polarization type. After spatial channel structure is decided, we contact polarization types which have considerable cases It is note that the proposed algorithms and analysis of dual polarized channel using SCM (Spatial Channel Model) optimize channel capacity and reduce the number of transmit antenna selection compare to heuristic method which has considerable 100 cases.

• 한국전자파학회논문지
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• 제24권4호
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• pp.357-365
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• 2013

기판 집적 도파관(Substrate Integrated Waveguide: SIW) 기술을 이용한 Ka 밴드의 35 GHz용 $4{\times}4$ 평면 배열 안테나를 제시한다. 전체 안테나 구조는 3층의 PCB(Printed Circuit Board) 적층 형태로 구성되며, top PCB에는 45도로 기울어진 직렬 방사 슬롯이 평면 배열로 방사부를 이룬다. 또한, 균일한 전력을 전달하고 안테나 전체 단면적을 최소화하기 위해 middle 및 bottom PCB에는 급전 SIW가 위치한다. 전체 안테나 개구면의 면적은 $750.76mm^2$이며, 유전율 2.2의 RT/Duroid 5880 기판을 적층하여 설계하였다. 각 방사부 및 급전부의 개별적인 전기적 특성은 full-wave 시뮬레이터인 CST MWS를 이용하여 확인하였다. 나아가 제안된 평면 배열 안테나는 대역폭 (490 MHz), 최대 이득(18.02 dBi), 부엽 레벨(-11.0 dB), 교차 편파 레벨(-20.16 dB)의 전기적 특성을 보인다.