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

In this paper, a half-sized unbalanced dipole antenna with fan-shaped and trapezoidal radiators on a printed circuit board was proposed. The VSWR and radiation patterns of the proposed antenna were investigated. As a result, the VSWR characteristics less than 2.0 and relative bandwidth of 110% over the frequency band of 3.1 GHz to 10.8 GHz from the experiments were obtained from a measurement. As the radiation patterns, the similar radiation patterns with an usual dipole antenna such as eight-shape and omni-directional radiation patterns were obtained at 3.1 GHz. Although the radiation patterns at 6.8 GHz and 10.6 GHz were slightly distorted compared with those of the usual dipole antennas, it is acceptable in practical use because the orientation of mobile devices in which the antenna could be built may change frequently, depending on how a user uses the devices.