A compact dual-polarized filtering base-station antenna is presented in this letter. The entire size (include the ground plane) of the element is only 0.53λ × 0.72λ × 0.14λ (λ is the wavelength of the central working frequency). Four vertical slots etched on the coupling cross slot are for improving the high-frequency suppression of the antenna. The C-slots on the Gnd1 reduce the cross-polarization ratio at the axial direction. The antenna shows a wide working bandwidth of 25.6% and a low cross-polarization ratio about 22 dB. In order to validate the design, a 1 × 3 linear array is fabricated and tested. The antenna array works at 3.3–4.0 GHz with the average gain about 11 dBi. Besides, the array remains a good out of band rejection more than −20 dB up to 9 GHz which exhibits a good harmonic suppression performance over a wideband.

中文翻译：

---

适用于 5G 应用的紧凑型双极化滤波基站天线

这封信中介绍了一种紧凑型双极化滤波基站天线。元件的整个尺寸（包括地平面）仅为0.53λ×0.72λ×0.14λ（λ为中心工作频率的波长）。耦合十字槽上刻有四个垂直槽，用于提高天线的高频抑制。Gnd1 上的 C 槽降低了轴向的交叉极化率。该天线具有 25.6% 的宽工作带宽和约 22 dB 的低交叉极化比。为了验证设计，制造并测试了一个 1 × 3 线性阵列。天线阵列的工作频率为 3.3–4.0 GHz，平均增益约为 11 dBi。此外，该阵列在高达 9 GHz 的频率范围内保持了超过 -20 dB 的良好带外抑制，在宽带上表现出良好的谐波抑制性能。