• Title/Summary/Keyword: Circular Polarization

Search Result 224, Processing Time 0.165 seconds

CP-OFDM System using Circular Polarization (원편파를 이용한 CP-OFDM 시스템)

  • 김병옥;하덕호
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
    • /
    • /
    • pp.34-38
    • /
    • 2001
  • This paper proposes a CP-OFDM(Orthogonal Frequency Division Multiplexing using Circular Polarization) system for improving the system performance. The circular polarization has a characteristic that it cannot receive the reflected waves which are reflected by odd times. By reducing the influences of the reflected waves, the circular polarization can reduce the time delay spread and the inter-channel interference. The guard interval needed for the OFDM frame can be minimized and the orthogonality between subchannels can be improved by using circular polarization. Therefore the proposed CP-OFDM system can improve the system performance as well as the spectrum efficiency. Both theoretical analysis and system simulation results are described.

  • PDF

Circular Polarization Diversity in Indoor Wireless Mobile Environments

  • Ha, Deock-Ho;Ko, Yeon-Hwa;An, Jae-Sung;Kim, Tai-Hong
    • Journal of electromagnetic engineering and science
    • /
    • v.4 no.3
    • /
    • pp.128-136
    • /
    • 2004
  • In this paper,. with the aim of achieving the expected performance improvement for a polarization diversity system, we analyzed two-branch polarization diversity at the receiving end of a mobile link which a transmitter emits circularly polarized wave. In this analysis, to calculate the correlation coefficient considered by XPD(cross polarization discrimination) between the two received signals, a simple theoretical model of circular polarization diversity is adopted. From the analysis results, it is clearly seen that the correlation coefficient of circular polarization diversity evaluated by the XPD is less than that of conventional linear polarization diversity. And also, we designed and implemented a circular polarization diversity system with micro-strip antenna. By using the circular polarization diversity system, we analyzed the measured data in indoor NLOS(Non-Line-Of-Sight) environments. From this analysis results, it is also clearly seen that the diversity effect of circular polarization diversity system shows better performance compared to the conventional linear diversity system by about 3 dB high.

The Fabrication and Performance Estimation of Circularly Polarization Diversity System for Multipath Fading Reduction (다중경로페이딩 경감을 위한 원편파 다이버시티 시스템 제작 및 성능 평가)

  • 이주현;김판신;안재성;김태홍;고연화;김흥진;하덕호
    • Proceedings of the IEEK Conference
    • /
    • /
    • pp.609-612
    • /
    • 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.

  • PDF

Polarization-Diversity Cross-Shaped Patch Antenna for Satellite-DMB Systems

  • Lim, Jong-Hyuk;Back, Gyu-Tae;Yun, Tae-Yeoul
    • ETRI Journal
    • /
    • v.32 no.2
    • /
    • pp.312-318
    • /
    • 2010
  • A small reconfigurable patch antenna is proposed to achieve polarization diversity for digital multimedia broadcasting systems at 2.6 GHz. To obtain polarization diversity, a pair of on-slit PIN diodes is inserted in each diagonal of a cross-shaped patch. Thus, four PIN-diodes on these slits are utilized to change the connection of the slits and thus achieve polarization. Bias circuits for the diodes are allocated in the cutting corner of the cross-shaped patch to minimize the antenna size. The antenna produces left-hand circular polarization, right-hand circular polarization, or linear polarization, depending on the PIN-diode status. Analysis of circular polarization operation is explicated. Measurements show a gain of about 1.5 dB, a cross polarization of about -20 dB, and an axial ratio of about 2.5 dB.

The Circular Polarization Diversity Effect Considering XPD Factor in an Indoor Radio Propagation Environment

  • Ahn Je-Sung;Ha Deock-Ho;Cho Pyung-Dong
    • Journal of electromagnetic engineering and science
    • /
    • v.6 no.1
    • /
    • pp.24-29
    • /
    • 2006
  • In this paper, we analyzed new two-branch polarization diversity at the receiving end of a mobile link which a transmitter emits circularly polarized wave. To analyze the correlation coefficient considered by XPD(Cross Polarization Discrimination) between the two received signals, a simple theoretical model of circular polarization diversity is adopted and experimental measurements are also conducted. From both theoretical and measurement results, it can be seen that the proposed circular polarization diversity scheme is more effective than that of the conventional linear polarization diversity.

Wideband circularly-polarized microstrip $1\times8$ array antenna for TX/RX dual operation at X-band

  • Yun, Jae-Seung;Noh, Haeng-sook;Jeon, Soon-Ik;Park, Jae-Ick
    • Proceedings of the IEEK Conference
    • /
    • /
    • pp.715-718
    • /
    • 2002
  • TX/RX dual microstrip 1$\times$8 sub-array antennas are designed, fabricated, and measured for a wideband array antennas in communications. They have a Right Handed Circular Polarization (RHCP) for TX from 7.9 to 8.4 GHz and Left Handed Circular Polarization (LHCP) for RX from 7.25 to 7.75 GHz. Two stacked patches are used for a wideband characteristics and cornertruncated square patches are adopted for a circular polarization. To enhance bandwidth characteristics of a circular polarization, 1$\times$2 sequential rotation arrays are applied. From the measured results, 1$\times$8 microstrip sub-array antennas have a good agreement with those of the simulation. Therefore the sub-array antennas are applicable to satellite communication antennas, active phased array antennas, and radiators in other antennas.

  • PDF

Circular Polarization Dielectric Resonator Antenna Excited by Single Loop Feed

  • Jeon, Sin-Hyung;Choi, Hyeng-Cheul;Kim, Hyeong-Dong
    • ETRI Journal
    • /
    • v.31 no.1
    • /
    • pp.74-76
    • /
    • 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.

  • PDF

Conformal Horn Antenna for Circular Polarization using Planar-type Radiator (평판형 방사소자를 이용한 원형편파용 혼 안테나 설계)

  • Jung, Young-Bae
    • Journal of IKEEE
    • /
    • v.16 no.3
    • /
    • pp.173-176
    • /
    • 2012
  • This paper introduces a novel horn antenna for circular polarization using a planar-type radiator. This antenna can be divided to two parts, microstrip antenna and square horn. The microstrip antenna has the role of feeder and polarizer of the horn antenna, and it is designed to stacked type having metal spacer for high gain, high isolation and wideband characteristic. Using the proposed antenna structure, the horn antenna needs not additional structure such as feeder and polarizer, and the size of it can be considerably reduced. The horn antenna has typical gain of 8dBi and 3-dB axial-ratio bandwidth around 4.9%.This antenna can widely used for various antenna system for mobile and satellite communication using circular polarization expecially in high frequency band.

Design of Microstrip array antennas for Tx/Rx dual operation at X-band (X-band 송/수신 겸용 마이크로스트립 배열 안테나 설계)

  • 노행숙;윤재승;전순익
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.27 no.12C
    • /
    • pp.1299-1305
    • /
    • 2002
  • Tx/Rx dual microstrip array antennas for satellite communications are designed, fabricated, and measured in this paper. They have a Right Handed Circular Polarization (RHCP) for Tx and Left Handed Circular Polarization (LHCP) for Rx. Two stacked patches are used for wideband characteristics and corner-truncated square patches are adopted for a circular polarization. To enhance bandwidth characteristics of a circular polarization, 2${\times}$1 sequential rotation mays are applied. From the measured results, 8${\times}$1 microstrip may antennas have a good agreement with those of the simulation. Therefore the array antennas are applicable to satellite communication antennas, active phased may antennas, and radiators in other antennas.

The Design and Fabrication for Wireless Repeater Patch Antenna of Wide-band Dual polarization (광대역 이중편파 무선 중계기용 패치안테나 설계 및 제작)

  • Lee, Han-Young
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.7 no.6
    • /
    • pp.1287-1292
    • /
    • 2012
  • In this paper, a dual polarization patch antenna operates at the wide bandwidth of 1.525GHz~1.665GHz was designed and fabricated. To obtain the wide bandwidth and high gain, increased height of air floor from GND was applied, and to get wide band axial ratio and high gain, parasitic patch was applied. The simulation and measurement showed good agreements, the VSWR was less than 1.9 at the frequency bandwidth, the return loss was less than -10dB, and the LHCP(Left Hand Circular Polarization) and RHCP(Right Hand Circular Polarization) isolation was less than -13dB at the frequency bandwidth.