A structural compact wideband low sidelobe antenna array operating at X and Ku bands is designed for meeting the requirements of the electronic systems. The antenna array could achieve the relative bandwidth of 54.5% and the sidelobe level below -30 dB with the longitudinal dimension of 4.5λg. The array consists of 48 dipole elements and a stripline weighted power divider. To extend the bandwidth of the dipole element, a short-circuited probe at the end of the feeding stripline is employed to compensate distribution capacitive effect. A parasitic patch over the dipole is utilized to improve the radiation performance. To reduce longitudinal dimension of the array, the layout of the power divider is optimized according to the optimal power ratio of each node from the topology design. The experimentally validation is conducted in the near-field microwave anechoic chamber.