Design of ultra-wideband bow-tie antenna in UHF band

In this paper, an ultra-wideband bow-tie antenna that works at ultrahigh frequency (UHF) by utilizing microstrip balun and loading with the cavity-backed is presented. By connecting two folded elements to the patches of the bowtie dipole, the compact dimensions of the antenna can be achieved. The proposed antenna has an operating bandwidth ranging from f₁ to f₂ (relative bandwidth above 108.5%), which fulfills the requirement of UWB antenna. The measurement results show that the VSWR is less than 2 in the operating bandwidth. The proposed antenna also provides stable peak gain, unidirectional radiation patterns, a small volume and an ultra-wideband.