Low-Profile Dipole Antenna With Enhanced Impedance and Gain Performance for Wideband Wireless Applications

A compact dipole-type antenna fed by coplanar striplines (CPSs) with enhanced impedance and gain performance across ultrawideband (UWB) operating bandwidth of 2.12–6 GHz is proposed in this letter. The proposed antenna consists of two conventional rectangular arms on the one side of a substrate, connected by shorting via holes to a pair of bigger arms on the other side of the substrate. With this structure, the bandwidth of a conventional dipole antenna is improved significantly, while the radiation pattern in the whole operating frequency remains consistent and lateral antenna dimension is reduced. The performance of the proposed antenna is validated experimentally using a wideband balun to realize the microstrip–coplanar-strip transition. The measured results show that the proposed antenna can achieve a gain of 2.2–3.8 dBi across a
${\rm VSWR}=2$
impedance bandwidth of 2.8:1.