Abstract: A wideband directional antenna loaded with a three-circle director is proposed. The overall size is 70 mm×30 mm×30 mm. Based on the three-dimensional dipole structure loaded with a three-circle director, the radiation characteristics of the antenna is improved in the bandwidth. It is shown that the antenna meets the penetration requirements of microwave detection in cerebral hemorrhage. The operating frequency band of the antenna is 1. 1-3. 57 GHz (104. 3%), and the maximum gain reaches 7. 24 dBi. Compared with antenna without director, the maximum gain is increased over 3 dB in the band. The antenna is processed and tested, and the measured results are in good agreement with the simulated. The antenna is imported into Sim4Life and a simulation study of cerebral hemorrhage is carried out. The results show that the antenna loaded with the director can obtain a stronger scattering signal inside the brain, which can be used in cerebral hemorrhage detection and other fields.