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Fourier Code for spatial filter in High Power Laser System

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Chinese Journal of Lasers 1998年第6期7卷 16-21页

作者： HU Wei 1 QIAN Liyan 2 ( 1 Laboratory of Light Transmission Optics, South China Normal University, Guangzhou 510631, China 2 Department of Mathematics, South China Normal University, Guangzhou 510631, China) Received March 3, 1998 Revis

１ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｃｏｎｓｔｒｕｃｔｉｏｎｏｆＳｈｅｎｇｕａｎｇ Ⅲｉｓｏｎｅｏｆｔｈｅｗｏｒｌｄｂｉｇｅｓｔｐｒｏｇｒａｍｓｉｎｌａｓｅｒｆａｃｉｌｉｔｙ．Ｉｔｉｓｖｅｒｙｉｍｐｏｒｔａｎｔｔｏｅｓｔ... 详细信息

１ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｃｏｎｓｔｒｕｃｔｉｏｎｏｆＳｈｅｎｇｕａｎｇ Ⅲｉｓｏｎｅｏｆｔｈｅｗｏｒｌｄｂｉｇｅｓｔｐｒｏｇｒａｍｓｉｎｌａｓｅｒｆａｃｉｌｉｔｙ．Ｉｔｉｓｖｅｒｙｉｍｐｏｒｔａｎｔｔｏｅｓｔａｂｌｉｓｈａｃｏｍｐｌｅｔｅｓｅ...

关键词： high power laser system computational coding Fourier coding spatial filter

Suppression for the Low-spatial-frequency Rings and Ripples of Laser Near-field Intensity Distribution in the spatial filter Used in ICF Laser Drive

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Chinese Journal of Lasers 1999年第3期 8-11页

作者： LIU Zhongyong WANG Tao FAN Dianyuan (Shanghai Institute of Optics and Fine Mechanics, The Chinese Academy of Sciences, Shanghai 201800, China) Received Dec. 10, 1998 Revised manuscript received Jan. 6, 1999

１ＩｎｔｒｏｄｕｃｔｉｏｎＵｎｉｆｏｒｍｉｔｙｏｆｔｈｅｆｌｕｅｎｃｅｄｉｓｔｒｉｂｕｔｉｏｎｄｅｌｉｖｅｒｅｄｂｙａｌａｓｅｒｉｓｅｓｅｎｔｉａｌｆｏｒｍａｎｙａｐｐｌｉｃａｔｉｏｎｓ，ｓｕｃｈａｓｏｐｔｉｃａｌｐ... 详细信息

１ＩｎｔｒｏｄｕｃｔｉｏｎＵｎｉｆｏｒｍｉｔｙｏｆｔｈｅｆｌｕｅｎｃｅｄｉｓｔｒｉｂｕｔｉｏｎｄｅｌｉｖｅｒｅｄｂｙａｌａｓｅｒｉｓｅｓｅｎｔｉａｌｆｏｒｍａｎｙａｐｐｌｉｃａｔｉｏｎｓ，ｓｕｃｈａｓｏｐｔｉｃａｌｐｒｏｃｅｓｉｎｇ，ｓｕｒｆａｃｅｔ...

关键词： spatial filter low spatial frequency rings (LSFRs) Gaussian aperture super Gaussian beams

Solid Velocity Measurement of Using spatial filter and Wavelet Transform

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Solid Velocity Measurement of Using Spatial Filter and Wavel...

A True-Time-Delay Array Architecture for Wideband Multi-Beam Tracking

第五届国际粉体检测与控制学术会议

作者： Wu Xinjie Wei Ying Wang Shi (Dpt.of automation,Northeastern University,Shenyang,110003)

The essential method for processing two phase flow signals is described based on spatial filter and wavelet transform.Firstly,spatial filtering effect of capacitance sensors is studied.Secondly,the relationship in solid velocity and band width is found.Thirdly,the capacitance sensors width of pass-band is gained by using the nature of wavelet transform filtering.Furthermore solid velocity is obtained.Finally,we give processing results of practical measured signals.

关键词： spatial filter wavelet transform width of pass-band two phase flow signals solid velocity

来源： cnki会议评论

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China Communications 2023年第8期20卷 65-77页

作者： Xiaowei Liu Guangliang Ren State Key Laboratory of Integrated Service Networks Xidian UniversityXi’an 710071China

The true-time delay(TTD)units are critical for solving beam squint and frequency selective fading inWideband Large-Scale Antenna Systems(LSASs).In this work,we propose a TTD array architecture for wideband multi-beam tracking that eliminates the beam squint phenomenon and filters out interference signals by applying a spatial filter and time delay estimations(TDEs).The paper presents a novel approach to spatial filter design by introducing a transformation matrix that can optimize the beam response in a specific direction and at a specific frequency.Using the variable fractional delay(VFD)filters,we propose a TDE algorithm with a Newton-Raphson iteration update process that corrects the arrival time delay difference between sensors.Simulations and examples have demonstrated that the proposed architecture can achieve beam tracking within 10 ms at the low signalto-noise ratio(SNR)and demodulation loss is less than 0.5 dB in wideband multi-beam scenarios.

关键词： true-time delay(TTD) spatial filter variable fractional delay(VFD) wideband multi-beam tracking time delay estimation(TDE)

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Two-dimensional non-spatial filtering based on holographic Bragg gratings

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Chinese Physics B 2010年第7期19卷 327-332页

作者：何焰蓝郑浩斌谭吉春丁道一郑光威王晓东王逍 Science College National University of Defense Technology Research Center of Laser Fusion China Academy of Engineering Physics

The filter made up of two gratings performs as a two-dimensional non-spatial filtering. This paper reports that the volume Bragg gratings are fabricated by interfering two collimated coherent laser beams in photopolymer. Diffraction efficiency of a single grating is up to 78% in Bragg＇s condition, then a two-dimensional non-spatial filter, which consists of two volume Bragg gratings and a half-wave plate, enables the laser beam filtered in two dimensions with the diffraction efficiency of 54%. The Bragg＇s condition and effect of polarisation on performances of the two-dimension filter are also discussed.

关键词： spatial filter Bragg gratings two-dimensional filtering polarisation

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A wideband beamforming method based on directional uniform circular arrays

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Science China(Information Sciences) 2010年第12期53卷 2600-2609页

作者： MU PengCheng ,YIN QinYe & ZHANG JianGuo Ministry of Education Key Lab for Intelligent Networks and Network Security,School of Electronics and Information Engineering,Xi’an Jiaotong University,Xi’an 710049,China Ministry of Education Key Lab for Intelligent Networks and Network Security School of Electronics and Information Engineering Xi’an Jiaotong University Xi’an China

A new method for solving the wideband beamforming problem is proposed in this paper based on directional uniform circular arrays.The basic idea is designing a narrowband beamforming spatial filter at a specific frequency and using the obtained filter weights directly to wideband signals,which reduces the complexities of designing and processing.Under the premise of knowing signals’ direction information,this paper uses the method of least square with linear constraints to design the narrowband spatial filter.Since the directional uniform circular array is insensitive to the variation of frequency,coincident beams and notches are obtained at different frequencies of the wideband signal by using the obtained narrowband spatial filter weights.The computation complexity of array signal processing can be greatly reduced by using the method proposed in this paper,which is convenient for real-time signal processing.

关键词： array signal processing wideband beamforming uniform circular array spatial filter least square

Processing Signals of Two-Phase Flow Based on Independent component Analysis (ICA)

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Processing Signals of Two-Phase Flow Based on Independent co...