基于特征模分析的菱形宽带天线设计

Design of diamond-shaped wideband antenna based on characteristic mode analysis

文章通过特征模分析提出一种结构简单的菱形超表面天线,天线沿Y轴对称,由6个菱形贴片和2个修改过后的菱形贴片组成。修改过后的菱形天线增强所需水平方向的宽边辐射,减弱垂直方向的电流强度。电场耦合槽为馈电部分并且本身可以看作半波缝隙天线引入新谐振点增加天线带宽;天线结构紧凑,尺寸仅为0.60λ_(0)×0.55λ_(0)(λ_(0)为中心频率对应的空间自由波长)。仿真结果表明,该天线频率在4.5~6.2 GHz范围内能够实现-10 dB带宽,相对带宽达到31.8%,高低频中心的谐振点分别为4.78、5.88 GHz。天线工作时的辐射性能良好,在方向图带宽内增益大于6 dB。

A kind of diamond-shaped metasurface antenna with simple structure is proposed through characteristic mode analysis(CMA).The antenna is symmetrical along the Y-axis and composed of six diamond-shaped patches and two modified diamond-shaped patches.The modified diamond-shaped antenna enhances the required broadside radiation in the horizontal direction and weakens the current intensity in the vertical direction.The electric field coupling slot is the feeding part and can be regarded as a half-wave slot antenna introducing a new resonance point to increase the antenna bandwidth.The antenna has a compact structure and the size is only 0.60λ_(0)×0.55λ_(0)(λ_(0)is the free space wavelength corresponding to the center frequency).The simulation results show that the antenna can achieve a-10 dB bandwidth at 4.5-6.2 GHz,and a relative bandwidth of 31.8%.The resonance points of the high and low frequency centers are 4.78 GHz and 5.88 GHz,respectively.The radiation performance of the antenna is good,and the gain is greater than 6 dB in the pattern bandwidth.