A broadband antenna with fan-shaped and trapezoidal elements on a printed circuit board for ultra-wideband radio

In this paper, a half-sized unbalanced dipole antenna with fan-shaped and trapezoidal elements on a printed circuit board is proposed. The VSWR and radiation patterns of the proposed antenna were investigated. As a result, VSWR characteristics less than 2.0 and a relative bandwidth of 110 % over the frequency band of 3.1 GHz to 10.8 GHz were obtained from measurements. Radiation patterns similar to those of a normal dipole antenna, such as eight-shape and omni-directional radiation patterns, were obtained at 3.1 GHz. Although the radiation patterns at 10.6 GHz were slightly distorted compared with those of normal dipole antennas, they are acceptable for practical use.