Small-size CPW-fed Quasi-Yagi antenna with round-ended bow-tie CPW-to-slotline transition

A compact and wideband CPW-fed Quasi-Yagi antenna is proposed and experimentally demonstrated in this paper. Impedance, radiation, and gain characteristics of this antenna are presented, and a prototype antenna is fabricated and measured. The measured impedance bandwidth, defined by -10dB reflection coefficient, can reach an operating bandwidth of 97% from 3.41 to 9.84GHz, over which the antenna exhibits excellent end-fire radiation with a front-to-back ratio of greater than 14dB and a moderate gain of better than 4.24dBi. Moreover, the overall size of the proposed antenna is only 27 × 30 mm
²
. In contrast to traditional microstrip CPW-fed quasi-Yagi antenna design, our proposed antenna features a smaller size and wider bandwidth.