Abstract
In this paper, a half-sized unbalanced dipole antenna with fan-shaped and trapezoidal radiators is proposed. In addition, the VSWR, input impedance characteristics, and radiation patterns of the proposed antenna were investigated. It was found that the antenna has a maximum bandwidth when the radius of the fan-shaped element is 12 mm, the length of the upper base is 12 mm, the length of the lower base is 20 mm, the height of the trapezoidal element is 22 mm, the distance between the fan-shaped and trapezoidal elements is 0.4 mm, and the thickness of the antenna elements is 1.6 mm. In spite of the radiator area being 60% that of an unbalanced dipole antenna with semicircular and trapezoidal radiators, VSWR characteristics less than 2.0 and a relative bandwidth of 133% over the frequency band of 3.0 to 15 GHz were obtained.
