Application of double negative materials to increase the power radiated by electrically small antennas
Application of double negative materials to increase the power radiated by electrically small antennas
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DOI：
10.1109/tap.2003.817561
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发表时间：
2003-10
影响因子：
5.7
通讯作者：
R. Ziolkowski;A. Kipple
中科院分区：
文献类型：
--
作者：
R. Ziolkowski;A. Kipple
用解析和数值方法研究了双负（DNG）材料（/spl epsiv//sub r/<0和/spl mu//sub r/<0）对电小偶极子天线的包围效应。嵌入在均匀的DNG介质中的无限小电偶极子的问题进行处理，其解析解表明，这种电小天线的行为，而不是电容，因为它会在自由空间。然后表明，一个适当设计的偶极-DNG壳组合增加了真实的功率辐射超过一个数量级的相应的自由空间的情况下。天线的电抗被示出为具有相应的减小。对该偶极-DNG壳系统内的无功功率的分析表明，DNG壳充当偶极的自然匹配网络。一个等效电路模型的介绍，证实了这一解释。几个案例来说明这些结果。当DNG介质与频率无关时，解释该偶极-DNG壳层系统中存储的能量，从而计算辐射Q的困难问题从几个角度进行了讨论。
The effect of surrounding an electrically small dipole antenna with a shell of double negative (DNG) material (/spl epsiv//sub r/<0 and /spl mu//sub r/<0) has been investigated both analytically and numerically. The problem of an infinitesimal electric dipole embedded in a homogeneous DNG medium is treated; its analytical solution shows that this electrically small antenna acts inductively rather than capacitively as it would in free space. It is then shown that a properly designed dipole-DNG shell combination increases the real power radiated by more than an order of magnitude over the corresponding free space case. The reactance of the antenna is shown to have a corresponding decrease. Analysis of the reactive power within this dipole-DNG shell system indicates that the DNG shell acts as a natural matching network for the dipole. An equivalent circuit model is introduced that confirms this explanation. Several cases are presented to illustrate these results. The difficult problem of interpreting the energy stored in this dipole-DNG shell system when the DNG medium is frequency independent and, hence, of calculating the radiation Q is discussed from several points of view.