A Ku-band wideband conformal array antenna with13×19elements is presented in the paper. The array has a spherical structure, and its element is a proximity-coupled stacked patches antenna with a cavity-backed ground plane. The stacked patches and the cavity produce multiple coupled resonances, which enhance the bandwidth of the element extremely. A simulated model with the reasonable dimensions is framed with the coupling analyses, and the effective simulated results and good computing efficiency are obtained simultaneously. The measured results of the center embedded element in the whole array show a bandwidth exceeding 40%VSWR<2, which is close to the simulated matching performance.