In this letter, a novel wideband circularly polarized (CP) crossed dipole antenna with frequency reconfiguration is proposed. By introducing two quasi‐Sierpinski fractal orthogonal dipoles printed on both sides of the substrate, compact, broadband and low cross‐polarization characteristics are achieved. The proposed antenna can be switched flexibly over two frequency bands via controlling the states of the PIN diodes inserted in each arm of the crossed dipole. The measured −10 dB impedance bandwidths of the antenna are 63% in 2.23–4.27 GHz and 12.5% in 4.04–4.58 GHz, respectively. Meanwhile, the 3 dB axial ratio bandwidths are 34.7% in 2.5–3.55 GHz and 4.16% in 4.23–4.41 GHz, respectively. The proposed antenna is desired to be applied in the future wireless communication systems.

中文翻译：

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具有紧凑结构和频率重构的宽带圆极化交叉偶极子天线

在这封信中，提出了一种具有频率重构功能的新型宽带圆极化（CP）交叉偶极天线。通过引入两个印刷在基板两侧的准Sierpinski分形正交偶极子，可以实现紧凑，宽带和低交叉极化的特性。通过控制插入交叉偶极子各臂中的PIN二极管的状态，可以在两个频带上灵活切换所建议的天线。测得的天线的-10 dB阻抗带宽在2.23–4.27 GHz中为63％，在4.04–4.58 GHz中为12.5％。同时，3 dB轴向比率带宽在2.5–3.55 GHz中为34.7％，在4.23–4.41 GHz中为4.16％。期望将所提出的天线应用于未来的无线通信系统中。