加载电磁带隙反射板的偶极天线系统的阻抗特性

Impedance characteristic of dipole antenna with reflection board of electromagnetic bandgap

对加载电磁带隙(EBG)反射板的偶极天线系统进行了仿真,重点研究了偶极天线系统的输入阻抗与EBG反射板架设高度的关系。仿真结果表明,当架设高度变化时天线的输入阻抗随之发生改变,即输入阻抗实部和虚部均随着高度的变化而变化。虽然输入阻抗的实部R随着架设高度的变化而变化,但其取值总是大于零,表明天线辐射是消耗电磁能量;而天线输入阻抗的虚部则表现出可正可负,表明当电磁带隙反射板的架设高度不同时,天线系统即可以呈现容性也可以是感性;当架设高度合适时,电磁带隙反射板将发生谐振,天线输入阻抗的虚部为零,天线辐射电磁波最为有效。

The simulation of the dipole antenna system with the electromagnetic bandgap(EBG)was implemented and it was focused on the input-impedance of dipole antenna system especially on the relationship between the input-impedance and the height between the dipole antenna and the EBG reflector board plane.The simulation results show that the input-impedance of antenna system changes with the height between the dipole antenna and the EBG board.Although the real part R of the input-impedance varies with the height,its value is always greater than zero,which means the antenna radiation consumes the electromagnetic energy.The imaginary part of the input impedance of the antenna can be positive or negative,which shows that when the height of electromagnetic bandgap changes,the antenna system can present capacity or inductivity.The electromagnetic bandgap reflection plate resonance occurs at appropriate height,the imaginary part of the input impedance of the antenna is zero and the antenna can effectively radiate electromagnetic waves.