In recent years, radio communication using ultrawideband (UWB) technology has shown great promise for ubiquitous application. We have already investigated and developed the cross type of unbalanced dipole antenna with semicircular and trapezoidal radiating elements, and we have confirmed that the cross type of unbalanced dipole antenna performed with VSWR characteristics less than 2.0 over the UWB frequency band. However, the cross type of unbalanced dipole antenna is too large for the antenna built in mobile equipment. In this paper, we investigated miniaturizing the cross type of unbalanced dipole antenna, and we proposed a miniaturized antenna, a cross type of unbalanced dipole antenna with the bent type of semicircular and trapezoidal radiating elements. As a result, the VSWR characteristics of the proposed antenna was less than 2.0 over the UWB frequency band enough in practical use.