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

Abstract

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.

A multiband quasi‐Yagi antenna using stepped driver and slotted ground for 2.4/3.5/5.2 GHz bands applications

“…Recently, quasi-Yagi antennas have attracted great attention due to their properties, such as high gain, end-fire radiation, planar form, and wide bandwidth. [13][14][15][16][17] Thus, they can be a good candidate for multiband antenna design. Designing a multiband quasi-Yagi antenna, however, is very challenging as the general characteristics of the antenna can easily be distorted for different frequency bands.…”

“…Similarly, monopole antennas exhibit low gain, and it is difficult to maintain the radiation characteristics of the antenna at different frequency bands. Recently, quasi‐Yagi antennas have attracted great attention due to their properties, such as high gain, end‐fire radiation, planar form, and wide bandwidth 13–17 . Thus, they can be a good candidate for multiband antenna design.…”