Electromagnetic Scattering Characteristics of PEC Targets in the Terahertz Regime
Electromagnetic Scattering Characteristics of PEC Targets in the Terahertz Regime
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DOI：
10.1109/map.2009.4939018
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发表时间：
2009-05
影响因子：
3.5
通讯作者：
Zhuo Li;T. Cui;X. J. Zhong;Y. Tao;Hai Lin
中科院分区：
文献类型：
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作者：
Zhuo Li;T. Cui;X. J. Zhong;Y. Tao;Hai Lin
利用基于射线的高频电磁散射技术研究了太赫兹（THz）频段内理想导电（PEC）目标的电磁散射特性。这些技术包括射弹法（SBR）和截楔增量长度衍射系数法（TW-ILDC）。基于物理光学（PO）和/或几何光学（GO）的原理，跟踪和计算与每条射线相关联的EM场。然后通过将每条射线和每个照明边缘的EM贡献相加来获得从PEC目标散射的总场。与以前报道的应用相比，这些方法结合在一起，以解决在太赫兹区域的三维（3D）散射问题。利用物理光学的解析公式和截断楔增量衍射系数法，考虑了入射光和弹跳光的多次反射效应，并部分考虑了截断楔增量衍射系数法中的二阶边缘衍射效应，得到了一种研究太赫兹散射的高效算法。它具有良好的协议与精确的积分求解器，多层快速多极子算法（MLFMA），不能用于处理大规模的太赫兹问题。计算了几种PEC目标在THz波段的单、双站雷达散射截面（RCS），验证了渐近方法的正确性和可靠性。分析了此类目标在太赫兹波段的电磁散射特性。观察和讨论了太赫兹和GHz区域之间的目标特性的巨大差异。
Electromagnetic (EM) scattering characteristics of perfectly electrical conducting (PEC) targets in the terahertz (THz) frequency range are investigated through the use of ray-based high-frequency EM techniques. These techniques include the methods of shooting and bouncing rays (SBR), and the truncated-wedge incremental-length diffraction coefficients (TW-ILDCs). The EM fields associated with each ray are tracked and computed, based on the principle of physical optics (PO) and/or geometrical optics (GO). The total field scattered from the PEC target is then obtained by summing up the EM contributions of each ray and each illuminated edge. In contrast to previously reported applications, these methods are combined together to solve three-dimensional (3D) scattering problems in the THz region. Due to the use of analytical formulas of physical optics and the truncated-wedge incremental-length diffraction coefficients method, the consideration of the multi-reflection effect in shooting and bouncing rays, and partially accounting for the second-order edge-diffraction effects in the truncated-wedge incremental-length diffraction coefficients method, we obtain an extremely efficient algorithm for studying THz scattering. It has excellent agreement with an accurate integral solver, the multilevel fast multipole algorithm (MLFMA), which cannot be used in handling large-scale THz problems. Both mono- and bistatic radar cross sections (RCS) of several PEC objects in the THz band are given to show the correctness and reliability of the asymptotic methods. The EM scattering characteristics of such targets in the THz region are analyzed. Great differences of the target characteristics between the THz and GHz regimes are observed and discussed.