Can Mixing Materials Make Electromagnetic Signals Travel Faster?
Can Mixing Materials Make Electromagnetic Signals Travel Faster?
复制标题
混合材料可以使电磁信号传播得更快吗？
DOI：
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发表时间：
2002
影响因子：
1.9
通讯作者：
K. Sølna
中科院分区：
文献类型：
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作者：
G. Milton;K. Sølna
假设一个复合材料由两相组成，我们在其中传播一个电磁信号，信号在复合材料中的传播速度取决于微结构。什么样的微观结构与电磁信号的最大和最小速度相关？在这里，我们表明，一个脉冲的群速度可以是更高的复合材料比在任何两个阶段。我们推导出复合材料中电磁信号群速度相对增加和减少的精确界限，并给出了相关的最佳微观结构。我们还发现，在复合材料中的脉冲可以有实质上更小的色散，在同一时间，实质上更大的群速度比脉冲在纯相位。
Suppose that a composite is constructed from two phases and that we propagate an electromagnetic signal through it. The velocity of the signal in the composite depends on the microstructure. What microstructures are associated with the maximum and minimum speeds of the electromagnetic signal? Here we show that the group velocity of a pulse can be higher in the composite than in either of the two phases. We derive sharp bounds for the relative increase and decrease in the group velocity of the electromagnetic signal in the composite and give the associated optimal microstructures. We also find that a pulse in a composite can have substantially smaller dispersion and, at the same time, substantially larger group velocity than pulses traveling in the pure phases.