A low-profile, high-gain, and low cross-polarization omnidirectional antenna is proposed. The antenna structure is pretty concise with convenient probe feeding and sandwich-structure design. The characteristic mode analysis shows that the antenna can excite quasi-TM01 and quasi-TM02 modes in a broadband and, thus, results in monopole radiation mode and low cross polarization in a broad operating band. The full-wave simulation and experiments were performed to verify the antenna design. The fabricated prototype antenna showed <2 dB unroundness and <−25 dB cross polarization in (4.8–11.1) GHz, with a relative bandwidth of 79.2% and a peak gain of 8.4 dBi at 9 GHz.

中文翻译：

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基于特征模理论的宽带高增益低交叉极化全向天线设计


提出了一种薄型、高增益、低交叉极化全向天线。天线结构非常简洁，探头馈电方便，三明治结构设计。特征模式分析表明，该天线可以在宽带内激发准TM01和准TM02模式，从而在宽工作频带内产生单极辐射模式和低交叉极化。进行全波仿真和实验来验证天线设计。制造的原型天线在 (4.8–11.1) GHz 下表现出 <2 dB 不圆度和 <−25 dB 交叉极化，相对带宽为 79.2%，在 9 GHz 下峰值增益为 8.4 dBi。