A printed quasi‐Yagi antenna with dual‐stub‐loaded parasitic strip director for bandwidth enhancement

A novel printed quasi-Yagi antenna with dual stubs loaded on a parasitic strip director has been presented. The impedance bandwidth is analyzed and compared when we add or eliminate the parasitic strip director. Then, two open stubs are loaded on the strip to excite an additional resonant mode, which lead to a wider impedance bandwidth. To demonstrate the effectiveness of this design, an antenna prototype is fabricated and tested. Experimental results show that the antenna provides a bandwidth ranging from 4.4 to 9.3 GHz and within the whole band larger than 4.1 dBi gain is achieved. Additionally, the proposed antenna presents a stable end-fire radiation directivity and low cross-polarization level at different frequencies with a compact structural size of 35 mm x 26 mm. (C) 2016 Wiley Periodicals, Inc.