• Title/Summary/Keyword: phased array antennas

Search Result 73, Processing Time 0.028 seconds

Feedback Simplification Scheme for Wireless Power Transfer Systems Based on Beamforming with Phased Array Antenna (위상배열 안테나를 이용한 빔포밍 기반 무선전력전송 시스템의 피드백 간소화 기법)

  • Roh, Tae-Rae;Kang, Gil-Mo;Shin, Oh-Soon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.30 no.3
    • /
    • pp.195-201
    • /
    • 2019
  • The effectiveness of the phased array antenna in wireless power transfer systems is due to its ability to form a beam pattern towards the desired direction. To maximize the efficiency of wireless power transfer through beamforming, the transmitter must recognize the information on the optimal transmission path. To achieve this, the transmitter usually transmits pilot signals periodically and the receiver extracts the optimal beamforming weights using the pilot signals. The receiver then feeds the beamforming weights back to the transmitter. In general, the amount of feedback increases with the number of antennas, which causes feedback overhead when there is a large number of antennas. In this paper, we propose a feedback simplification scheme based on the far-field approximation method. The simulation results are provided to validate the impact of the simplified feedback on the beam pattern.

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.

Small Broadband Phased Array Antenna with Compact Phase-Shift Circuits (간결한 위상 변위 회로를 갖는 소형 광대역 위상 배열 안테나)

  • 한상민;권구형;김영식
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.14 no.10
    • /
    • pp.1071-1078
    • /
    • 2003
  • In this paper, the planar, compact, and broadband phased array antenna system for IMT-2000 applications has been investigated. Two methods far designing a low-cost and low-complex beam-farming network are proposed. First, a new compact and broadband phase shifter with continuously controlled phase bits is designed by using parallel coupled lines. Second, its equivalent phase delay line is suggested to be capable of replacing the complex phase shifter with a reference phase bit on a phased array antenna. For the purpose of achieving the broadband system, in addition to the broadband phase shifter, a wide-slot antenna with a ground reflector is utilized as an element antenna. Therefore, the phased array antenna system has achieved compact size, broad bandwidth, and wide steering angle, although it has low complexity and low fabrication cost. The 3${\times}$1 phased array antenna system has a compact size of 1.6 λ${\times}$ l.6 λ, which is the sufficient ground plane of the wide-slot antenna. Experimental results present that the S$\_$11/ has less than 15 dB within the band and its radiation patterns on an E-plane have the capability of steering an antenna beam from -29$^{\circ}$to +30$^{\circ}$.

A design of the microstrip phased array antenna with the slot-coupled structure for the base station of mobile communication (슬롯결합구조를 갖는 이동통신 기지국용 마이크로스트립 위상배열 안테나의 설계)

  • 장정필;장병준;윤영중;박한규
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.21 no.12
    • /
    • pp.3205-3214
    • /
    • 1996
  • In this paper, the microstrip phased array antennas with coupling-slots for the base station of mobile communication is proposed and anlyzed with accurate analysis method which is based on both reciprocity principle and full-wave analysis. The basis functions used for the numerical analysis are determined depending upon the accuracy, convergence properties of the solution, and the computation time. The patch uses 3 EB mode and the slot uses IPWS mode. The designed phased array antenna has 8 slot-coupled microstrip patch array elements and the beam scanning capability is obtained by using the 4-bit PIN-diode phase shifters as switching devices which are consisted of the loaded line phase shifters for 30.deg. and 60.deg. and the reflection type phase shifters for 90.deg. and 180.deg. repectively. The 4-bits phase shifters which aremade by connecting each phase shifter have about 2.deg.-3.deg. phase errors and their insertion loss are about 3dB for each phase state. The fabricated 8-element phased array antenna with 4-bits phase shifters provides 12.deg.-14.deg. beamwidths depending on the scanning angle and is capable of scanning its beam to .+-.45.deg. with 9.deg. intervals, and the gain 12dBi. The overall results show that the slot-coupled phased array antenna has great advantages of wideband, high gain and reduced spurious radiation. Also, the antenna can be made small and thin. Furthermore, the scanning property of this antenna allows for its application in several areas, such as mobile communication system and PCS.

  • PDF

High-Performance Bidirectional Active Phased-Array Antenna Coupled by Transmission Line (선로결합에 의한 쌍방향 능동 위상차 배열 안테나의 동작특성 향상)

  • Choi, Young-Kyu;Kim, Ki-Rae
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.12 no.3
    • /
    • pp.427-437
    • /
    • 2008
  • In order to increase the coupling efficiency of the power and phase of the active phase array antenna, we have fabricated the active phased-array antenna which is coupled by the transmission line, and investigated the relationship between the length of the coupling transmission line and coupling power and phase. The following three types of driving method - (1) giving the frequency difference between the two active antenna, (2) applying the input signal to the one side of the two antennas, and changing the eigen frequency of the other side antenna, (3) appling the different phase inputs to the active antennas was investigated. The experimental results showed that the interval of the antenna elements has not affected the power and the phase of the antenna.

Effect of Finite Substrate Size on the Radiation Characteristics of H-plane Linear Array Antennas (유한한 기판 크기가 H-평면 선형 배열 안테나의 방사 특성에 미치는 영향)

  • Yoon, Young-Min;Kim, Boo-Gyoun
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.50 no.5
    • /
    • pp.39-49
    • /
    • 2013
  • The effect of the finite substrate size on the radiation characteristics of H-plane linear microstrip array antennas is investigated. The radiation characteristics versus scan angle are systematically analyzed for 5-element H-plane linear array antennas with various substrate sizes and element spacings for the substrates with different dielectric constants. The distance between the antenna center and the substrate edge on the E-plane for the enhancement of the radiation characteristics of the array antenna is presented.

Fabrication of the Capacitance Controlled Active Integrated Phased Array Antenna and It's Scanning Characteristics (용량 조정형 능동 집적 배열 안테나의 제작과 방사 방향 주사 특성)

  • Choi, Young-Kyu;Nam, Beong-Geun;Shin, Sang-Yeol
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.56 no.10
    • /
    • pp.1807-1813
    • /
    • 2007
  • This paper deals with extending the variable natural oscillation frequency range of an active integrated FET oscillator. In this paper, we conform experimentally that the variable range of the natural oscillation frequency is expanded about three times in the oscillator controlled by the varactor diode. When the frequency difference is given to the oscillators in the two element antenna system, phase difference appeared between the oscillators. The 2-, 3-, 4-, 5-element patch antenna arrays are composed for the beam scanning experiments. All the above patch antennas show good phased array characteristics. The range of the scanning angle is about $30^{\circ}$, and the radiation power is gradually increased from $50{\mu}W\;to\;200{\mu}W$. The radiation patterns we sharpened as the number of elements is increased.

An optical true time delay for 10 GHz linear phased array antennas composed of optical 2×2 MEMS switches and fiber delay lines (광 2×2 MEMS 스위치와 광섬유 지연선로를 이용한 10 GHz 선형 위상배열 안테나용 광 실시간 지연선로)

  • 이백송;신종덕;김부균
    • Korean Journal of Optics and Photonics
    • /
    • v.14 no.4
    • /
    • pp.466-472
    • /
    • 2003
  • In this paper, we proposed an optical true time-delay (TTD) feeder system for phased array antennas (PAAs). The system possesses high-speed beam scan capability since, in this scheme, different lengths of fiber delay-lines are selected by optical 2${\times}$2 MEMS switches at high speed. An optical TTD capable of beam scanning in one of eight different directions has been built for 10 GHz linear PAA systems. Experimental results on time delay measurements show that the maximum time delay error is less than 0.2 ps corresponding to a scan angle error of less than 0.84o. We have also designed a 10 GHz linear PAA composed of eight micro-strip patch antenna elements driven by the proposed TTD, and the radiation patterns of this PAA have been analyzed by simulation.

Design of L-Band Cylindrical Active Phase Array Antenna Using Bent Dipoles (접힌 다이폴 구조를 적용한 L-Band 원통형 능동 위상배열 안테나 설계)

  • Lee, Man-Gyu;Kwon, Ickjin
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.50 no.6
    • /
    • pp.43-55
    • /
    • 2013
  • In this paper, we propose a cylindrical active phased array antenna of Beam Steering Characteristics in the horizontal plane(H-plane) and vertical plane(E-Plane) on the cylinder form array structure. We design the bent dipole antenna of the cylindrical array structure adapted excellent mutual-coupling characteristics, designed and manufactured the cylindrical array antennas and power combiner/divider unit for power dividing and combining on the antenna. The radiating elements array spacing of Cylindrical array antenna were determined to avoid grating lobes at half power beam steering. Beam steering of the antenna was implemented with 6-bit phase shifter in the transceiver and have been designed based on the characteristics the antenna beam steering at -24 degrees to 24 degrees horizontal, vertical 0 degrees to 36 degrees beam steering. A cylindrical active phased array antenna that produced for verification the performance of the antenna are measured radiation characteristics in accordance with beam steering at L-Band.