Wideband quasi‐Yagi antenna with stable radiation patterns for base‐station applications

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 | S 11 | ≤ −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.