加载分形EBG地的低剖面Fabry-Perot谐振腔天线设计

Design of a Low-Profile Fabry-Perot Resonant Cavity Antenna Loaded with Fractal EBG Ground Plane

本文设计了一种新型的高增益低剖面Fabry-Perot(F-P)谐振腔天线.该谐振腔天线通过在下层地平面加载电磁带隙结构(Electromagnetic Band-Gap,EBG)改变接地板反射相位,采用Minkowski分形结构来设计EBG单元,使得接地板反射相位分布更为均匀,从而降低了天线的剖面高度.覆盖层采用人工磁导体(Artificial Magnetic Conductor,AMC)均匀贴片阵列,电磁波在口径面上实现同向叠加,天线获得高增益定向特性.辐射源采用传统的矩形微带贴片,结构简单.仿真结果表明,天线的剖面高度降低为λ/4(λ为5.8 GHz自由空间波长),阻抗带宽(|S11|<-10 dB)为3.1%(5.78 GHz~5.96 GHz).在工作频率5.8 GHz处,天线增益达到17 dBi.

A novel low-profile,high-gain Fabry-Perot(F-P)resonant cavity antenna is proposed in this paper.The ground plate reflection phase is changed by loading the EBG elements on the lower ground plane which based on the Minkowski fractal structure.The reflection phase distribution on the ground plane is much more uniform,thus,the profile of the antenna is reduced.The superstrate of the antenna adopted an artificial magnetic conductor(AMC)uniform patch array.Electromagnetic wave is superimposed on the aperture surface in the same direction,so that the antenna achieves high-gain directional characteristic.The primary radiator is a rectangular microstrip patch with simple structure.The simulation results show that the profile of the antenna is reduced toλ/4(λis the operating wavelength in free space at 5.8 GHz),the impedance bandwidth of the antenna(|S_(11)<-10 dB|)is 3.1%(about 5.78 GHz~5.96 GHz).The gain at 5.8 GHz reaches up to 17 dBi.