Abstract: In order to meet the demand for wideband and highgain performance of the frequency modulation continuous wave (FMCW) radar system terminal antenna, a butterfly printed dipole antenna array has been designed. The parallel stripline feed network is used for the connection and the balun is used to transform the parallel stripline to a 50Ω coaxial feed connector. The antenna element adopts a wide dipole tapered structure to increase the bandwidth and forms a 4×4 planar antenna array to increase the gain. The design of unequal power division and multisection impedance matching for the feed network is utilized to suppress the side lobes and expand the bandwidth. The antenna has been fabricated and measured. The measured results show that the antenna array has a return loss of more than 10 dB and a relative bandwidth of 54% in the 3.8-6.6 GHz band. Within this range, antenna gain is higher than 15 dB and the highest gain is 17 dB.