According to the current trend of miniaturization and broadband development of wireless communication systems, a broadband dipole with multiple resonant modes is designed. First of all, the resonant modes of the inversed T-shaped conductor are analyzed by the theory of characteristic mode and the first two resonant modes are chosen; then a parasitic resonant dipole element is introduced without affecting the resonant characteristics of the inversed T-shaped conductor; finally, a lumped port is placed at the place that the three resonant modes have common maximum current value, these three resonant modes are excited simultaneously, and a wideband resonant antenna with three resonant modes is obtained. The simulated and measured results are in good agreement, with the final operating bandwidth of the antenna ranging from 1. 8 to 2. 56 GHz (34. 9% relative bandwidth). As a result, the designed antenna is not only simple in structure, but also good in performance and can be widely used in wireless communication systems.