A dual-linear polarisation reconfigurable broadband omnidirectional antenna is proposed. The radiating structure consists of a slotted ring and an inner square loop, which can generate omnidirectional radiation based on characteristic mode analysis. A dipole feeding network is designed and four PIN diodes are loaded into the feeding network to change the current flow direction. The final dimensions of the proposed antenna are 0.2 × 0.2 λ ₀ ( λ ₀ is the free-space wavelength), with a low profile of 0.006 λ ₀ . The measured results show that the antenna achieves an overlapped bandwidth of 49.6% (from 480.2 to 797.5 MHz) with | S ₁₁ | < −10 dB and a gain variation between −1 and 0.4 dBi. The proposed antenna can be applied to a digital terrestrial television service and an unmanned aerial vehicle pattern measuring system.

中文翻译：

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双线性极化可重构宽带全向天线

提出了一种双线性极化可重构宽带全向天线。辐射结构由一个开槽环和一个内部方环组成，它们可以基于特征模式分析生成全向辐射。设计了一个偶极馈电网络，并将四个PIN二极管加载到馈电网络中以更改电流方向。拟议天线的最终尺寸为0.2×0.2 λ ₀（ λ ₀是自由空间波长），低剖面为0.006 λ ₀ 。测量结果表明，该天线实现了49.6％的重叠带宽（从480.2到797.5 MHz）。 小号 ₁₁ | <-10 dB，增益变化在-1和0.4 dBi之间。所提出的天线可以应用于数字地面电视服务和无人机模式测量系统。