A small sized ceramic dielectric patch antenna is designed and implemented for GPS/GLONASS combined receiver, and it shows a wideband characteristics with circular polarization. For the miniaturization of the antenna, high-permittivity dielectric material is used, and the wideband characteristics with low axial-ratio is achieved by using dual feed with 90$^{circ}$ phase difference. The measured data of the manufactured antenna show that the bandwidth is 242 MHz, the axial ratio is less than 3 dB, the half-power beam-width is more than 112$^{circ}$, and the antenna satisfies the required characteristics of the GPS/GLONASS antenna.