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用低杂波鉴相器对相位测量系统各通道经进行了相位校准,得到了各通道的相位电压关系曲线,并进行了线性拟合,线性拟合误差小于3°;推导出了相位电压关系表达式,与校准得到的相位电压曲线相比平均误差小于0.7°。该系统已成功用于HL-2A装置低杂波实验,对4支速调管的输出相位进行了测量,并得到了放电过程中相位随阴极高压波动的曲线,得出了阴极电压波动2.2%引起相位波动13.8°的结论。     

HL-2A 装置低杂波鉴相器标定与实验研究

用低杂波鉴相器对相位测量系统各通道经进行了相位校准,得到了各通道的相位电压关系曲线,并进行了线性拟合,线性拟合误差小于3°;推导出了相位电压关系表达式,与校准得到的相位电压曲线相比平均误差小于0.7°。该系统已成功用于HL-2A 装置低杂波实验,对4 支速调管的输出相位进行了测量,并得到了放电过程中相位随阴极高压波动的曲线,得出了阴极电压波动2.2%引起相位波动13.8°的结论。     

EAST上基于端口密度测量的低杂波耦合研究

介绍了一套安装在EAST装置低杂波天线端口上方,用来测量端口附近电子密度的Langmuir三探针系统及其初步实验结果。此探针系统由探针、测量电路、数据采集以及数据处理四部分构成。实验结果表明：在低杂波天线端口充气的条件下,低杂波注入后端口密度会有明显的增加。端口密度与反射系数的关系与理论趋势一致,EAST上低杂波耦合的最佳密度出现在4~5×10¹⁷m^-3。     

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HL-2A装置的1MW低杂波电流驱动系统在单只速调管的条件下进行了系统的工程调试。建立了低杂波真空系统,天线真空度为2.3Pa,传输系统真空度为4.30×102Pa,天线对装置的漏率为1.675×10-4Pa?m3.s-1。采用低真空条件下充气的方法提高了系统的功率传输能力,有效地降低和避免了打火情况的发生,初步分析了低杂波系统的真空性能以及对HL-2A装置真空的影响。     

HL-3装置强场侧低杂波天线的波谱设计

为研究高参数等离子体的低杂波可近性,基于HL-3装置设计了一套位于强场侧的低杂波天线。利用ALOHA代码对强场侧的天线进行模拟分析,针对只有一个单元的PAM天线,分别对其子波导数量、有源/无源子波导的高度、宽度和壁厚等参数进行模拟,得到了天线的最佳结构和尺寸。最终优化后的天线发射参数为：波谱中心的平行折射率N|为2.25,天线的反射系数小于2%,方向性系数大于0.59。     

用于光学相控阵天线的初始校准算法（英文）

针对光学相控阵存在难以校准的相位误差的问题,改进了旋转电矢量相控阵天线初始相位校准方法 .与原始方法相比,该方法改变了相位计算方法,并且每测算出一个单元的相位误差立即进行相位矫正,然后测算并矫正下一个单元的相位误差,避免了原始方法在初始相位误差分布范围较广且光功率测量精度有限的情况下可能出现的π相位错误.仿真结果表明,原始方法校准后主瓣光强的平均值最多达到理想值的70.8%,标准差至少为19.1%;而改进方法校准后的主瓣强度均值至少可以达到理想值的87.6%,标准差最大7.3%,证明了改进方法具有更高的统计精度和可预测性.制备了9×9光学相控阵芯片,芯片初始的栅瓣抑制比为2.12 dB,改进的旋转电矢量法校准后则达到了4.68 dB,证明了该方法的有效性与实际应用价值.     

EAST低杂波天线耦合特性研究

采用数值模拟方法研究了EAST低杂波天线的耦合特性。基于二维线性耦合理论,计算了天线功率反射系数和方向性系数与等离子体参数的关系,分析了无源波导对天线耦合性能的影响,并给出了不同参数下天线的功率谱。结果表明,无源波导使天线的方向性略有下降,但减小了天线的功率反射系数,这有利于天线与等离子体的耦合。     

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采用数值模拟方法研究了EAST低杂波天线的耦合特性。基于二维线性耦合理论,计算了天线功率反射系数和方向性系数与等离子体参数的关系,分析了无源波导对天线耦合性能的影响,并给出了不同参数下天线的功率谱。结果表明,无源波导使天线的方向性略有下降,但减小了天线的功率反射系数,这有利于天线与等离子体的耦合。     

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HT-7上用于低杂波电流驱动的相控波导阵天线采用的是标准波导,长和宽都是有限值。在考虑了天线上下排波导之间可能存在的极向相位差以及电磁干扰时,通过数值模拟的方法,分别得到了低杂波在环向方向的平行功率谱和在极向方向的极向功率谱。由于极向波矢的存在,低杂波进入等离子体的入射方向会发生改变。最后在不同极向相位差下对低杂波进入等离子体的入射方向进行了简要的计算和讨论。     

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HT-7上用于低杂波电流驱动的相控波导阵天线采用的是标准波导,长和宽都是有限值。在考虑了天线上下排波导之间可能存在的极向相位差以及电磁干扰时,通过数值模拟的方法,分别得到了低杂波在环向方向的平行功率谱和在极向方向的极向功率谱。由于极向波矢的存在,低杂波进入等离子体的入射方向会发生改变。最后在不同极向相位差下对低杂波进入等离子体的入射方向进行了简要的计算和讨论。     

Millimeter wave components for electronically controllable antennas

Many present and future military and commercial systems operating at millimeter wave frequencies require the use of sophisticated electronically controllable antennas for maximum capability and flexibility. Electronic control of the antenna pattern is provided by electronically switchable phase control of each radiating element such as that achieved in phased array antennas or via electronically reconfigurable antenna feeds referred to as beam forming networks (BFN). Multibeam antennas provided by BFN'S can be realized using switches, variable power dividers (VPD), and phase shifters. Ferrite materials and associated application technology are being utilized to achieve these switchable RF control components at millimeter wave frequencies. The performance achievable in ferrite switchable circulators, variable power dividers and phase shifters in the frequency region from 20 to 100 GHz is discussed.     

Simulation on effect of poloidal power spectrum on lower hybrid wave propagation

The coupling of lower hybrid wave to the plasma is a crucial issue for efficient current drive in tokamaks. This paper establishes a new coupling model which assumes the antenna to be a curved face and the plasma to be a cylinder. Power spectrum considering the coupling between wave-guides in both poloidal and toroidal direction is simply estimated and discussed. The effect of the poloidal wave vector on wave propagation, power deposition and driven current is also investigated with the help of lower hybrid current drive code. Results show that the poloidal wave vector affects the ray tracing, and also has effect on power deposition and driven current. The effect of the poloidal wave vector on power deposition and driven current profile depends on plasma parameters. Preliminary studies suggest that it seems possible to control the current profile by adjusting the poloidal phase difference between the waveguide in poloidal direction.     

固体火箭发动机尾焰电磁波衰减试验验证技术研究

通过对固体火箭发动机地面试验现场环境及尾焰电磁波衰减近场测试技术进行研究,设计了基于矢量网络分析仪的固体火箭发动机尾焰电磁波衰减试验验证系统,介绍了尾焰电磁波衰减试验验证总体方案,现场测试方法,尾焰电磁波衰减现场测试系统硬件组成,测试系统原位校准技术,现场测试天线构建和天线位置校准方法等的研究。对构建好的测试系统进行了工程应用,并取得了良好的试验效果。     

“网格式平行线法”在螺纹参数测量中的应用

在计算机视觉理论基础上发展起来的视觉检测(vision inspection)技术具有非接触、速度快、精度适中、可实现在线等优点，已广泛地应用于工业产品的在线检测。在计算机视觉检测技术中CCD摄像机是一个最关键的器件，其参数是否准确决定了检测的精度。所以，摄像机标定是视觉检测技术中最基本的也是最重要的一步。在比较其他标定方法的基础上，为了解决传统标定方法对螺纹图像测量系统所带来的一系列问题，采用了一种新的图像测量系统的标定方法——网格式平行线标定方法，该方法运用了CCD亚像素细分技术及调焦技术，可直接得到纵横2个方向的像素，经过理论分析及实验结果均表明，采用该方法具有标定简单、精度高、重复性好等优点，是一种较好的螺纹图像测量系统标定方法。     

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The design and implement of logical control and monitor system of the lower hybrid current drive (LHCD) system on HL-2A tokamak was present. The system was based on the SIEMENS S7-400 series PLC. The performance on anti-interference was increased by using the industrial ethernet network, optical fiber isolation, embedded controller technology. The interlocks, parameter setting and remote monitor were established. The lower hybrid wave was injected into HL-2A plasma with the logical control system. It shows the logical control system was successfully developed.     

Ultra-thin single-layer transparent geometrical phase gradient metasurface and its application to high-gain circularly-polarized lens antenna

A new method to design an ultra-thin high-gain circularly-polarized antenna system with high efficiency is proposed based on the geometrical phase gradient metasurface(GPGM).With an accuracy control of the transmission phase and also the high transmission amplitude,the GPGM is capable of manipulating an electromagnetic wave arbitrarily.A focusing transmission lens working at Ku band is well optimized with the F /D of 0.32.A good focusing effect is demonstrated clearly by theoretical calculation and electromagnetic simulation.For further application,an ultra-thin single-layer transmissive lens antenna based on the proposed focusing metasurface operating at 13 GHz is implemented and launched by an original patch antenna from the perspective of high integration,simple structure,and low cost.Numerical and experimental results coincide well,indicating the advantages of the antenna system,such as a high gain of 17.6 d B,the axis ratio better than 2 d B,a high aperture efficiency of 41%,and also a simple fabrication process based on the convenient print circuit board technology.The good performance of the proposed antenna indicates promising applications in portable communication systems.     

X波段4单元微带天线阵辐照响应

采用时域有限差分法,并结合导体边缘奇异性处理技术,在不降低计算效率的情况下,保证了计算精度,得到了高功率电磁脉冲辐照下X波段4单元微带天线阵的响应。计算结果表明:馈电点最大响应电压峰值由天线阵各阵元接收的入射脉冲在馈电点叠加引起,且天线阵中主要存在与馈电点激励天线阵不同模式的波。响应电压峰值随着入射脉冲波矢量与正z轴夹角的减小而增大,随着入射脉冲波矢量xOy平面投影与正x轴夹角的增大而增大,频谱随着上述两个夹角的增大均向低频转移。     

Displaced phase-amplitude variables for waves on finite background

Wave amplification in nonlinear dispersive wave equations may be caused by nonlinear focussing of waves from a certain background. In the model of nonlinear Schrödinger equation we will introduce a transformation to displaced phase-amplitude variables with respect to a background of monochromatic waves. The potential energy in the Hamiltonian then depends essentially on the phase. Looking as a special case to phases that are time independent, the oscillator equation for the signal at each position becomes autonomous, with the change of phase with position as only driving force for a spatial evolution towards extreme waves. This is observed to be the governing process of wave amplification in classes of already known solutions of NLS, namely the Akhmediev-, Ma- and Peregrine-solitons. We investigate the case of the soliton on finite background in detail in this Letter as the solution that descibes the complete spatial evolution of modulational instability from background to extreme waves.