Department of Electronic & Information Engineering, Korea Aerospace University, Goyang 10540, Korea.
Sensors (Basel). 2022 Jul 15;22(14):5293. doi: 10.3390/s22145293.
This article demonstrates that the complex value of S of an antenna, acquired in a multi-monostatic configuration, can be used for localization of a dielectric anomaly hidden inside a dielectric background medium when the antenna is placed close (~5 mm) to the geometry. It uses an Inverse Synthetic Aperture Radar (ISAR) imaging framework where data is acquired at multiple frequencies and look-angles. Initially, near-field scattering data are used for simulation to validate this methodology since the basic derivation of the Multiple Signal Classification (MUSIC) algorithm is based on the plain wave assumption. Later on, from an applications perspective, data acquisition is performed using an antipodal Vivaldi antenna that has eight constant-width slots on each arm. This antenna operates in a frequency range of 1 to 8.5 GHz and its S is fed to the 2D MUSIC algorithm with spatial smoothing whereas the antenna artifact and background effect are removed by subtracting the average S at each antenna location. Measurements reveal that this methodology gives accurate results with both homogeneous and inhomogeneous backgrounds because the size of data sub-arrays trades between the image noise and resolution, hence reducing the effect of inhomogeneity in the background. In addition to near-field ISAR imaging, this study can be used in the ongoing research on breast tumors and brain stroke detection, among others.
本文证明，当天线放置在靠近（约 5 毫米）几何形状的位置时，在多单基地配置中获得的天线 S 的复数值可用于定位隐藏在介电背景介质中的介电异常。它使用逆合成孔径雷达（ISAR）成像框架，在该框架中，在多个频率和视角下获取数据。最初，由于 MUSIC 算法的基本推导基于平面波假设，因此使用近场散射数据进行模拟以验证此方法。后来，从应用的角度来看，使用具有每个臂上的八个恒定宽度狭槽的对偶 Vivaldi 天线进行数据采集。该天线在 1 到 8.5 GHz 的频率范围内工作，其 S 通过空间平滑馈送到 2D MUSIC 算法，而天线伪影和背景效应通过减去每个天线位置的平均 S 来去除。测量结果表明，由于数据子阵的大小在图像噪声和分辨率之间进行交换，因此这种方法在均匀和非均匀背景下都能得到准确的结果，从而降低了背景不均匀性的影响。除了近场 ISAR 成像外，这项研究还可用于正在进行的乳腺癌和脑卒中等肿瘤检测研究。
