The bandwidth will get narrow when the size of HF antenna is small. To overcome this problem, a novel miniaturized HF antenna composed of hemispherical wire grids with performance similar to the electric dipole is presented in this paper. The antenna has simple structure and is easy to feed. The largest dimension of this antenna is 3.6 m, which is 3.6％ of its lowest frequency wavelength, and 36％ of its highest frequency wavelength. The antenna is simulated with the help of CST MWS. A 1/5 scale model is manufactured and measured. The results demonstrate that the relative impedance bandwidth is 40％ without loading or external matching networks while maintaining acceptable performance. A method of broadening frequency range by loading lumped elements is further discussed, and simulation and test verification have been done. The designed antenna can be widely used in HF communication system, over-the-horizon radar and so on.