• Title/Summary/Keyword: active antenna array

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Study on Beamforming of Conformal Array Antenna Using Support Vector Regression (Support Vector Regression을 이용한 컨포멀 배열 안테나의 빔 형성 연구)

  • Lee, Kang-In;Jung, Sang-Hoon;Ryu, Hong-Kyun;Yoon, Young-Joong;Nam, Sang-Wook;Chung, Young-Seek
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.11
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    • pp.868-877
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    • 2018
  • In this paper, we propose a new beamforming algorithm for a conformal array antenna based on support vector regression(SVR). While the conventional least squares method(LSM) considers all sample errors, SVR considers errors beyond the given error bound to obtain the optimum weight vector, which has a sparse solution and the advantage of the minimization of the overfitting problem. To verify the performance of the proposed algorithm, we apply SVR to the experimentally measured active element patterns of the conformal array antenna and obtain the weights for beamforming. In addition, we compare the beamforming results of SVR and LSM.

Optimized Design of Wide-Band Subarray Using a Genetic Algorithm (유전 알고리즘을 이용한 광대역 부배열 최적화 설계)

  • Kim, Doo-Soo;Lee, Dong-Koog;Kim, Seon-Joo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.23 no.4
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    • pp.415-423
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    • 2012
  • This paper specifies on optimized design of wide-band subarray using a Genetic Algorithm. First wide-band radiator was designed at triangle lattice of infinite array structure. It is the radiator of notch type that has a wide-band characteristic of ratio 2:1 between maximum and minimum frequency satisfying active reflection coefficient under -10 dB at boresight. And a Genetic Algorithm was applied to optimize subarray partition of antenna consisting of 1,100 array elements. It was confirmed that an optimized subarray antenna has a 4.5-5.5 dB more improved maximum SLL (Side-Lobe Level) than regular subarray antenna.

Wideband circularly-polarized microstrip 1×8 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
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    • 2002.07b
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    • pp.715-718
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    • 2002
  • TX/RX dual microstrip 1×8 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, 1×2 sequential rotation arrays are applied. From the measured results, 1×8 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.

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The Design of Electronically Beam Steeling Array Antenna Using 4 Parasitic Elements (4개의 기생 소자를 이용한 전자적인 빔 조향 배열 안테나 설계)

  • Kim, Young-Goo;Choi, Ik-Guen;Kim, Tae-Hong;You, Jong-Jun;Kang, Sang-Gee
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.2
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    • pp.167-173
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    • 2009
  • This paper proposes an electronically beam steering array antenna, consisting of single fed active element and 4 parasitic elements, operating in 5.8 GHz ISM band. Beam steering can be achieved by controlling the reactance of the variable reactance control circuit connected to the load of the parasitic elements without using the high cost phase shifters. The proposed antenna realizes ±30 beam scanning of E-plane and H-plane with the below -10 dB return loss in ISM band. The gain of the 6.187.53dBi in E-plane and 7.0227.779dBi in H-plane is shown in the scanning range.

A Transmission Technique of Multichannel Receiver Data for the Phased-Array Radar (위상 배열레이더의 다채널 수신 데이터 전송 기법)

  • Jeong, Myung-Deuk;Kim, Han-Sung
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.23 no.10
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    • pp.1188-1195
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    • 2012
  • The trend for the development of radar is the active phased-array radar system. The trade-off between the processing speed and the number of the signal process board for the real time signal processing has to be optimized particularly in multichannel radar system. This paper introduces a transmission technique in order to transmit a large amount of received data from an Antenna Part to Signal Process Part. As a result, the number of the S/L board(COTS board) is reduced to one half, and the margin of the data transmission rate is about 2 times higher than the original method.

Analysis of the Required Limit on APAA Aperture using Statistical Simulation for HAPS

  • Ku, Bon-Jun;Park, Jong-Min;Kim, Yang-Su;Ahn, Do-Seob
    • Proceedings of the IEEK Conference
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    • 2002.07b
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    • pp.1335-1338
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    • 2002
  • This paper presents the analysis of the required limit on a multibeam active phased array antenna (APAA) aperture using the statistical simulation for a High Altitude Platform Station (HAPS). The simulation takes into account the random errors caused by the non-identity of the array elements and the inaccuracy of the antenna calibration. The results of our statistical simulation show that the strict requirements on the sidelobe envelope for HAPSs can be met when the amplitude and phase distribution errors are minor, a condition which may be achieved by using digital beam forming.

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A Study on Adaptive Pattern Null Synthesis for Active Phased Array Antenna (능동위상배열안테나의 적응형 패턴 널 형성에 관한 연구)

  • Jung, Jin-Woo;Park, Sung-Il
    • The Journal of the Korea institute of electronic communication sciences
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    • v.16 no.3
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    • pp.407-416
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    • 2021
  • An active phased array antennas can not only electrically steer the beam by controlling the weighting of the excitation signal, but can also form a pattern null in the direction of the interference source. The weight of the excitation signal to steer the main beam can be easily calculated based on the position of the radiating element. In addition, the weight of the excited signal for pattern null formation can also be calculated by setting the required radiation pattern and using WLSM(Weighted Least Squares Method). However, in a general wireless communication network environment, the location of the interference source is unknown. Therefore, an adaptive pattern null synthesis is needed. In this paper, it was confirmed that pattern null synthesis according to the required radiation characteristic was possible. And based on this, adaptive pattern null synthesis into the direction of an interference source was studied using a binary search algorithm based on observation area. As a result of conducting a simulation based on the presented technique, it was confirmed that adaptive pattern null forming into the direction of an interference is possible in efficient way.

5-Bit Digital Phase Shifter for 12 GHz Band Active Phased Array Antenna System (12 GHz대 능동 위상 배열 안테나 시스템을 위한 5-비트 디지털 위상 변위기)

  • 김경식;최익권
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.3
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    • pp.308-315
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    • 2002
  • In this paper, the 5-bit digital phase shiftier with 10 InGaAs HEMTs is designed and fabricated for U.S. mobile DBS receiving active phased array antenna system in 12 GHz band. 11.25 , 22.5 and 45 phase bits are designed in leaded-line type. 90 and 180 phase bits are designed in reflection type combined with ring hybrid. The return loss more than 17.5 ㏈, insertion louts less than 7.8 ㏈, and maximum phase error of ±6for 32 phase responses are measured in 12.2 GHz~ 12.7 GHz band.

A Study of T/R Module Output Compensation Method for Active Synthetic Aperture Radar (능동형 SAR 시스템의 송수신 모듈 출력 보정 방법 연구)

  • Yi, Dong-Woo;Lee, Jong-Hwan;Kim, Se-Young;Jeon, Byoung-Tae
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.21 no.9
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    • pp.955-964
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    • 2010
  • In this paper, a compensation method of the amplitude and phase errors from the T/R(Transmit/Receive) modules in an active SAR(Synthetic Aperture Radar) system is introduced. The errors are defined and classified, and characterized by analyzing the measurement data acquired from the pilot test. To compensate these errors, a control methodology of T/R modules output is proposed. Before the compensation is applied, 16 T/R modules integrated on the active SAR antenna show the amplitude in 28.2~29.0 dBm and the phase in 101.7165.2. After the compensation, the amplitude and phase are distributed in 27.4~28.0 dBm and 116.1120.0 respectively. The antenna beam patterns generated by the array theory with the distributions are compared, and the proposed method is verified as good to apply for the active SAR system.

Receiver Gain of Active Phased Array Radar-Dependence on ADC Characteristic (ADC 특성에 따른 능동 위상 배열 레이더 수신기의 이득 설정 방법)

  • Kim, Tae-Hwan;Choi, Beyung-Gwan;Lee, Hee-Young;Cho, Choon-Sik
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.1
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    • pp.52-59
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    • 2009
  • In modern radars, dynamic range requirements far severed due to high CNR(Clutter-to-Noise Ratio) environment operation scenario. ADC spurious signal restricted the required dynamic range. In this paper, receiver gain of active phased array radar dependent on ADC nonlinear characteristic was analyzed. Within limited scope of ADC SFDR which blocks required system dynamic range, ADC dynamic range reaches trade-off with ADC SNR loss. Comparing antenna stage output noise voltage to that of ADC input, receiver gain was mathematically analyzed. Finally the whole contents were explained from the application example.