"时间窗"对天线时域平面近场测试结果的影响

天线时域近场测试技术是一种新兴的、测试宽带场和工作在窄脉冲激励下天线辐射场的高效的测试技术.因为它可以利用"时间窗"技术进行信号处理,使其相对频域测试具有独特的优势.本文在已建立的天线时域近场测试系统的基础上,从实验的角度,对"时间窗"参数在天线时域平面近场测试中的影响进行验证分析.举例了三个波段标准天线方向图的测试分析结果,并得出初步结论.     

天线时域近场测量实验系统研究

总结了天线时域近场测量技术研究中进行系统实验验证在个阶段的进展情况,提出了组建天线时域近场测试验证系统的基本框架,总结了验证实验的基本过程和思路,提出了一种利用离散傅立叶反变换（IDF）技术完成天线的时域近场测量的方法,本文给出了各个实验阶段的测试结果,据此得出了对于天线的时域近场测量技术肯定的结论。     

天线时域近场测量技术与实验系统

天线时域近场测试技术是一种新兴、高效的天线测试技术,能够快速精确地测量出天线的时域场和宽带特性。介绍了成功组建的国内第一套天线时域平面近场测试系统简单情况,给出了L、S、C、X四个波段的标准天线方向图验证测试结果,把测试结果跟频域近、远场测试系统上测得的结果进行了比较,证明测试理论的正确性和测试系统的实用性。     

天线时域平面近场测试实验系统的研究

天线时域近场测试技术是一种新兴、高效的天线测试技术,能够快速精确地测量出天线的时域场和宽带特性。目前我们已成功组建了国内第一套天线时域平面近场测试实验系统,并对L、S、C、X四个波段的标准天线方向图进行了验证测试,把测试结果跟频域近、远场测试系统上测得的结果进行比较,证明时域近场测试理论的正确性和测试系统的实用性。本文对这套系统的组成结构和天线的测试结果进行说明分析。     

天线时域近场测量误差分析

本文对时域近场扫描测试中的几种误差做了简要介绍，并建立仿真模型集中分析了时间基准误差和采样时间间隔误差的影响，得出了仿真结果和初步结论。     

超低副瓣天线平面近场测量采样间距误差分析

基于超低副瓣天线测试对精度的要求,利用计算机模拟的方法研究了平面近场测量中采样间距误差对超低副瓣天线副瓣的影响,得到了一些规律和有用的结果,并证明了Nyquisty采样定理在超低副瓣天线测试中的适用性和正确性。     

天线时域平面近场测量系统的研究

时域近场测量作为一种新发展起来的天线测量技术,具有和通常的频域测量不同的独特优势,它能得到天线的时域特性和宽带特性.首先介绍了时域平面近场测量系统的构成,为了能对雷达进行测量,系统采用了使用矢量信号源模拟产生复杂雷达信号的方案,并对标准增益喇叭进行了验证测试,把测试结果和理论仿真、频域近场测试结果进行了比对,证实了时域...     

时域平面近场散射测量研究

时域平面近场散射测量是一种在近场区域进行散射测量的技术,可以有效地进行宽带的散射测量,具有超宽带测试、可以获得时域散射场、空间利用率高等特点,针对时域平面近场散射测量技术体系,在时域近场测量的理论基础上,提出了系统组建方案,论证了系统的可行性,开展了针对典型目标的验证测试,并对测量结果进行了初步的误差分析.证明了时域平面近场散射测量的有效性.     

天线时域近场测量中的时基及幅度修正技术

 在天线时域近场测量中由于脉冲信号源的时基抖动和幅度变化所带来的误差是测量中最主要的误差,其中尤以时基误差最为严重,它使得方向图畸变到了无法容忍的程度.本文即针对此问题提出了天线时域近场测量中的时基及幅度修正技术.该技术在测量通道之外增加了一个参考通道,通过检测参考通道信号提取出脉冲信号源的时基及幅度变化,进而以此修正测量通道的信号.大量的实际测量表明该技术稳定可靠.通过对比试验发现,使用该技术的时域近场测量结果的精度达到甚至优于频域近场测量结果的精度.     

时域近场测试中的采样面截断误差分析与修正

采样面截断误差是影响近场测试结果的一个很重要的因素。本文结合频域近场测量中对采样面截断误差的分析结果,根据时域近场测量的时域近场特性,借助PSTD算法和PML技术,提出一种修正时域近场测量采样面截断误差的新方法,数值例子验证了方法的有效性。     

A general technique to correct probe position errors in planarnear-field measurements to arbitrary accuracy

A general theoretical procedure is presented to remove known probe-position errors when planar near-field data are transformed to the far field. The measured data are represented as a Taylor series whose terms contain the error function and the ideal spectrum of the antenna. This representation is then assumed to be an actual near-field existing on an error-free regularly spaced two-dimensional scan plane. By inverting the Taylor series, the ideal spectrum in terms of the measured data and the position errors is obtained. The solution is given by an infinite series of an error operator acting on data containing errors of measurement. This error operator is the Taylor series without the zeroth-order term. The nth order approximation to the ideal near-field of the antenna can be explicitly constructed by inspection of the structure of the error operator. Convergence of the approximation is examined. Computer simulations are used to demonstrate the excellent results obtained with this technique, as well as to demonstrate the convergence of the error-corrected fields to the true solution     

Near-field qualification methodology

A methodology that is a combination of analysis, computer simulation, component certification, self-tests, and comparison tests is presented for the accuracy qualification of near-field antenna measurement ranges. The analysis uses closed-form equations to establish upper-bound far-field determination errors due to near-field measurement errors. Computer simulation is used to model the specific near-field measurement errors associated with the near-field measurement system components. The closed-form equations and computer simulations are used to form a near-field error budget for each of the near-field measurement system components. A near-field system component certification is undertaken to measure the near-field measurement system component error and establish that they are within the error budget     

基于Gerchberg-Papoulis算法的平面近场截断误差修正方法研究

在平面近场天线测量中,有限扫描面截断是影响测量精度的主要误差源之一,找到解决截断误差的方法是天线测量的研究重点之一.文中将平面近场天线测量中由有限区域内的场求平面波谱的过程抽象为带限函数外推的数学模型,从实际测量中的近远场变换理论出发,论证了GP（Gerchberg-Papoulis）算法应用在平面近场测量中在理论上是切实可行的.将GP算法应用在平面近场天线测量中,并分析了不同迭代次数算法的修正情况.结果表明,随着算法迭代次数的增多,可信角域外计算方向图与理论方向图差别明显减小.因此,本文的方法能够明显减小平面近场测量中截断误差的影响.除此以外,还分析了误差对算法收敛性的影响,结果表明,误差对算法修正效果影响较大.     

平面近场比较法增益测量的误差分析

从平面近场天线测量理论出发,结合比较法增益测量的实际情况,推导出近场比较法测量天线增益的计算公式。然后对近场比较法增益测量中常见的3种误差进行了实验对比,定量的分析了其对于天线增益测量的影响,并最终给出了相应的降低增益测量误差的方法。     

平面波谱恢复算法在平面近场测量中的应用

介绍用于天线平面近场测量的一种近远场变换新算法。该法利用被测天线的平面波谱和口径场幅相分布之间的关系,以及天线口面的约束条件,用G-P迭代算法从平面波谱的置信谱域部分恢复出置信谱域外的平面波谱。这种方法减小了较小截断角下有限扫描面对测量精度的影响,并提高了天线近场测量的效率。     

Phaseless bi-polar planar near-field measurements and diagnosticsof array antennas

Antenna near-field measurements typically require very accurate measurement of the near-field phase. There are applications where an accurate phase measurement may not be practically achievable. Phaseless measurements are beginning to emerge as an alternative microwave antenna measurements technique when phase cannot be directly measured. There are many important aspects for successful implementation of a phaseless measurement algorithm. This paper presents appropriate phaseless measurement requirements and a phase retrieval algorithm tailored for the bi-polar planar near-field antenna measurement technique. Two amplitude measurements and a squared amplitude optimal sampling interpolation method are integrated with an iterative Fourier procedure to first retrieve the phase information and then construct both the far-field pattern and diagnostic characteristics of the antenna under test. In order to critically examine the methodologies developed in this paper, phaseless measurement results for two different array antennas are presented and compared to results obtained when the near-field amplitude and phase are directly measured     

基于傅立叶变换频移特性的平面近场测试方法

为了满足快速和无相测试现场天线的需求,文中提出了一种基于傅立叶变换频移特性的平面近场测 试方法。该方法采用多探头技术,利用各个通道的移相,达到天线角域的移动,实现了任意指向角信号的采集,具有 测试快速、使用便捷的特点,特别适用于天线的大规模生产测试和现场测试等。对一个标准喇叭天线进行了平面近 场扫描测量,对比了用传统近场数据处理插值方式得到的和用频移性质得到的天线远场方向图(E 面)。实验显示, 该方法具有与传统近场测试方法相同的效果,能有效地测试天线方向图。     

Pilot signal-based real-time measurement and correction of phase errors caused by microwave cable flexing in planar near-field tests

Millimeter and submillimeter wave receivers in scanning planar near-field test systems are commonly based on harmonic mixing and thus require at least one flexible microwave cable to be connected to them. The phase errors originated in these cables get multiplied and added to the phase of the final detected signal. A complete submillimeter setup with on-the-fly measurement of phase errors is presented. The novel phase error correction system is based on the use of a pilot signal to measure the phase errors caused by cable flexing. The measured phase error surface in the quiet-zone region of a 310 GHz compact antenna test range (CATR) based on a hologram is shown as an application example. The maximum measured phase error due to the cable within a 80/spl times/90 cm/sup 2/ scan area was 38/spl deg/.     

平面近场天线多任务测试系统工程设计

提出了一种平面近场天线多任务测试系统的工程设计方法,该方法通过增加多功能天线测试控制器和远控微波开关对传统平面近场测试系统进行升级,使其具备对平面相控阵雷达天线多频点、多波位、多通道一次最多可测试35个天线方向图的测试能力。对新引入的幅相误差及扫描面截断误差进行了计算分析。大型相控阵天线的实测结果表明,在提高测试效率的同时,其测试精度亦能满足测试要求。