A novel wideband quasi-Yagi antenna with a dipole driver, an octagon-shaped director, and a box-shaped reflector is proposed in this letter. The dipole driver is excited by a wideband balun with a stepped microstrip for good impedance matching. In addition, the proposed octagon-shaped director not only realizes good impedance matching but also stabilizes the radiation pattern. To further stabilize the radiation pattern, the reflector of the antenna is designed in a box shape. As a result, the proposed antenna achieves a wide bandwidth of 81.7% for |S₁₁| ≤ −15 dB from 1.65 to 3.93 GHz. Additionally, the proposed antenna obtains a stable half-power beamwidth of 62 ± 5° in the horizontal plane and a high gain of 8.3 ± 1 dBi from 1.7 to 3.6 GHz.

中文翻译：

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用于基站应用的具有稳定辐射方向图的宽带准八木天线

这封信中提出了一种新型宽带准八木天线，它具有偶极子驱动器、八角形导向器和箱形反射器。偶极子驱动器由具有阶梯式微带的宽带巴伦激励，以实现良好的阻抗匹配。此外，所提出的八边形导向器不仅实现了良好的阻抗匹配，而且稳定了辐射方向图。为了进一步稳定辐射方向图，天线的反射器设计成箱形。因此，所提出的天线实现了 81.7% 的宽带宽 | S ₁₁ | 从 1.65 到 3.93 GHz ≤ -15 dB。此外，所提出的天线在水平面上获得了 62 ± 5° 的稳定半功率波束宽度和从 1.7 到 3.6 GHz 的 8.3 ± 1 dBi 的高增益。