Characterization of an Implicitly Resistively-Loaded Monopole Antenna in Lossy Liquid Media
Characterization of an Implicitly Resistively-Loaded Monopole Antenna in Lossy Liquid Media
复制标题
DOI：
10.1155/2008/580782
复制
发表时间：
2008-01-01
影响因子：
1.5
通讯作者：
Paulsen, Keith D.
中科院分区：
文献类型：
--
作者：
Fox, Colleen J.;Meaney, Paul M.;Paulsen, Keith D.
乳腺的微波断层成像用于癌症检测是一个相当感兴趣的话题，因为它有可能利用正常组织和恶性组织之间明显的高介电特性对比。实现成像系统的一个重要组件是用于信号传输/检测的天线阵列。单极子天线在我们的实现中被证明是有用的，因为它可以容易和准确地建模，并且当配置在成像阵列中时，它可以被定位在高单元密度的成像目标附近。当在用于将信号耦合到乳房的液体介质中辐射时，其频率响应显著展宽，使其适合于宽带光谱成像。然而，在更高的频率下，波束方向图偏离所需的水平面更远，并且当位于靠近液/气界面时可能会引起不需要的多径贡献。在本文中，我们研究了这些天线的行为，并为它们在更高频率下的有效使用制定了策略，特别是当它们位于所使用的耦合流体表面附近时。结果表明，当天线中心距离液体表面近2 cm时，可以使用2 GHz以上的频率。版权所有(C)2008，Colleen J.Fox等人。
Microwave tomographic imaging of the breast for cancer detection is a topic of considerable interest because of the potential to exploit the apparent high-dielectric property contrast between normal and malignant tissue. An important component in the realization of an imaging system is the antenna array to be used for signal transmission/detection. The monopole antenna has proven to be useful in our implementation because it can be easily and accurately modeled and can be positioned in close proximity to the imaging target with high-element density when configured in an imaging array. Its frequency response is broadened considerably when radiating in the liquid medium that is used to couple the signals into the breast making it suitable for broadband spectral imaging. However, at higher frequencies, the beam patterns steer further away from the desired horizontal plane and can cause unwanted multipath contributions when located in close proximity to the liquid/air interface. In this paper, we have studied the behavior of these antennas and devised strategies for their effective use at higher frequencies, especially when positioned near the surface of the coupling fluid which is used. The results show that frequencies in excess of 2 GHz can be used when the antenna centers are located as close as 2 cm from the liquid surface. Copyright (C) 2008 Colleen J. Fox et al.