宽带圆极化单极天线的设计

摘要

本文设计了一个宽带圆极化单极天线.天线的辐射单元采用C型结构，使天线的基模分解成两个正交的简并模，从而实现圆极化.通过在接地板增加一个枝节，改善了天线的阻抗带宽和轴比带宽.仿真和测量结果表明：天线可以工作在3.4~3.6 GHz 的 WiMAX 频段，天线阻抗带宽为44.4%(2.89~4.54 GHz)，轴比带宽为29.1%(3.12~4.18 GHz).%A broadband circularly polarized monopole antenna is proposed in this paper.To realize cir-cularly polarized radiation,a C-shaped element is used,which can split the fundamental mode into two orthogonal near-degenerate degenerate modes.By adding a stub on the ground,both the impedance bandwidth and the axial ratio bandwidth could be improved.The simulated and measured results show that the proposed antenna can operate at Wimax bands (3.4 GHz~3.6 GHz).The impedance band-width of the antenna is 44.4% (2.89 GHz~4.54 GHz),and the 3 dB axial ratio bandwidth is 29.1%(3.12 GHz~4.18 GHz).