下载中心 | 技术文章

Current techniques for testing of aircraft radomes are time consuming, not as precise as desired, and requires dedicated far field test range, compact test range, or anechoic chamber, or other specific systems for measuring one or other of the parameters.

 Dual-polarized probes with wide-bandwidth operational capabilities are highly desirable for time-efficient Planar Near-Field (PNF) measurements [1]-[3]. However, sometimes the performance tradeoffs necessary to achieve the desired operating bandwidth make such probes impractical for many applications.

V-band (50-75GHz) applications such as 5G and myriad others are the catalyst for high performance near-field antenna measurement systems. For Spherical Near-Field (SNF), the traditional approaches at millimeter wave frequencies collect two full spheres of data in the near-field where each sphere samples one of two linear and orthogonal fields of the antenna under test (AUT).

Automotive antenna measurements are increasingly demanding. Modern cars are equipped with a large number of integrated antennas, spanning a wide frequency range for a large number of applications. Integrated antennas are strongly coupled with the structure, final testing are thus performed on the vehicle to accurately determine the performance.

The adoption of millimeter wave phased arrays for a variety of applications has led to an increased need for on-chip antenna measurements. The antenna elements are tested via micro-probe connections due to their tiny dimensions. For typical wireless applications (e.g. 5G/NR or IEEE 802.11.ad) these phased arrays, are expected to provide near omni-directional coverage.

近来在计算电磁（CEM）工具中使用测量数据作为近场源，即使在天线特性和几何形状未知而不能将其纳入全波模型[1- 4]的情况下，也可以在数值模拟中代表天线。 近场源由天线的等效电流代表组成，通过来自测量辐射图的逆源方法[5-9]制备。 这个将数值模拟和天线测量结合在一起的链接已经通过一个活动的验证，这其中涉及了MVG和不同的软件（SW）供应商[10-15]。 在本文的第一部分，验证的最新结果完成了[1-3]中描述的活动。 在本文的第二部分，测量和模拟之间的关联应用于更复杂和/或现实的问题，包括散射问题。

通常，在近场到远场变换期间，准确的球面近场天线测量补偿了探测图案。 根据探头模态内容的复杂性和所需的精度，可以应用不同的探头校正（PC）技术。 通常的做法是在考虑到整个探测光谱的情况下，区分仅补偿探针的μ| = 1个球面模式的一阶PC和全PC。 应用PC时要考虑的另一个关键因素是探针表征。 为了获得非常准确的结果，通常的做法是在专门的测量活动中校准探头，不幸的是，它常常是耗时且昂贵的。 或者，可以使用模拟探头性能来执行PC。 本文介绍了使用校准或模拟探针进行的全序列和一阶PC之间的比较调查。

 In spherical Near Field (NF) measurements postprocessing techniques based on spatial filtering have been presented as promising tools for the mitigation of echoes or stray signals deriving from the surrounding environment. The spatial filtering is very efficient in measurement scenarios with a stationary Antenna Under Test (AUT).

Dual  polarized  wideband  probes  are convenient for accurate  and  time  efficient Planar  Near Field  (PNF)  antenna testing  [1]-[2].  Traditional probe  designs  are  often bandwidth limited and electrically large leading to high scattering [3]-[4] in PNF  measurements with  short  probe-AUT distances.