Broadband CPS-fed Yagi-Uda antenna

A broadband coplanar stripline-fed Yagi-Uda antenna is presented. The antenna has a feedline structure that is much simpler than other Yagi-Uda antennas, and provides more design flexibility in arranging the reflector owing to the absence of a large ground plane. To improve the impedance match, a taper is inserted between the wide-line/small-gap and the narrow-line/large-gap CPS. The proposed antenna has a bandwidth of 3.9–5.9 GHz for a −10 dB reflection coefficient and a gain of 6.5–8.0 dBi. At the centre frequency of 4.9 GHz, the antenna has gain of 7.1 dBi, and a half-power beamwidth (HPBW) of 73° in the E-plane and 98° in the H-plane.