中文摘要：

设计了一种由银纳米纤维周期排列成各向异性的圆环形超材料,在二维空间实现全向辐射的高效率空间功率合成。研究发现在太赫兹频率下该各向异性超材料径向介电常数趋于零。通过数值仿真观察TM极化的电磁波磁场强度经过圆环形径向各向异性零折射超常介质时磁场空间分布。计算表明,无论激励源位置如何和激励源数量多少,TM极化的电磁波磁场强度在经过此超常介质后,总能实现电磁波全向辐射。不同激励源合成的磁场强度通过此径向零折射超常介质能产生空间相干的全向辐射,最终实现全向辐射的空间功率合成。

英文摘要：

Herein a circular ring shaped anisotropic metamaterial made of periodic array of silver nanofibers were presented to realize high-efficiency spatial power combination for omnidirectional radiation in two-dimensional case.The radial permittivity of the metamaterial approached zero at terahertz frequencies.The TM polarized magnetic field distributions through the circular ring shaped metamaterial with radially anisotropic zero-index were observed.The simulation results showed that the TM polarized electromagnetic waves radiate omnidirectionally through this metamaterial,no matter where the source was located inside the circular ring and how many the sources were.The results demonstrated that a circular ring of radial zero-index metamaterial can make different excitation sources radiate EM waves omnidirectionally and coherently,and ultimately achieve omnidirectional spatial power combination.