A new differential frequency-reconfigurable antenna based on dipoles is presented in this letter. The basic structure of the proposed antenna consists of two pairs of vertical arms forming two dipoles, the feeding structure, mode switching structure, and p-i-n diodes. By switching “on” and “off” p-i-n diodes, the antenna can resonate at two states, and thus work centered at 3.5 and 5.5 GHz, respectively. Though the two states correspond to different resonant modes, the effective radiation parts are the same and the mode switching structure will not contribute to the far field for both states. This results in similar radiation patterns for both states. Besides, the proposed antenna is also simple in structure and wide in bandwidth. The measured −10 dB impedance bandwidths are 2.89–4.07 GHz (33%) and 5.1–6.19 GHz (19.8%) for the two states, respectively.

中文翻译：

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用于 Sub-6GHz 5G 和 WLAN 应用的基于偶极子的差频可重构天线

这封信中介绍了一种基于偶极子的新型差分频率可重构天线。所提出天线的基本结构由形成两个偶极子的两对垂直臂、馈电结构、模式切换结构和 pin 二极管组成。通过“打开”和“关闭”pin 二极管，天线可以在两种状态下谐振，从而分别以 3.5 GHz 和 5.5 GHz 为中心工作。虽然两种状态对应不同的谐振模式，但有效辐射部分相同，并且模式切换结构不会对两种状态的远场做出贡献。这导致两种状态的辐射模式相似。此外，所提出的天线结构简单，带宽宽。对于这两种状态，测得的 −10 dB 阻抗带宽为 2.89–4.07 GHz (33%) 和 5.1–6.19 GHz (19.8%)，