Abstract: In this paper, a shared-aperture planar phased array antenna operated at C and Ku band with wide-angle scan and high-power capacity is designed. The proposed phased array contains a printed dipole element-based 4×4 C-band array and a Ku-band array composed of 9×8 hybrid zeroth-order resonance patch elements. The wide-angle scanning performance of the designed phased array attributes the success to the wide-beam radiation of the dual-band elements. The bottom zeroth-order resonance patch element can not only be used as the Ku-band wide-beam radiation element, but also supplies the zero-phased reflection for the C-band printed dipoles which generate the wide-beam patterns based on the image theory. Furthermore, the antenna is designed with all metals buried by substrates to avoid air breakdown, and thus to improve the power capacity of the phased array. Full-wave simulation results show that the designed array can obtain a ±45° beam scan with its gain fluctuation less than 3 dB in both C and Ku bands, and the power capacity of the array reaches 18.9 MW when the total input power is 1 W.