An L-band patch-antenna system for CubeSat applications is presented in this paper. The high-permittivity dielectric loading reduces the size of individual antennas to make them suitable for a CubeSat platform. Two circularly polarized patch antennas were designed for the downlink and uplink frequencies of 1.53 and 1.63 GHz, respectively, and the antenna prototypes were characterized. A two-element, sequentially rotated antenna array was designed using the uplink patch element at 1.63 GHz, with a beam tilt of 20° from broadside. The array is to be employed in a system of four arrays that provide two tilted beams with dual-band coverage in each beam, for an increased system capacity. The arrays are located on the backside of the 3U-CubeSat solar panels, facing Earth. While the panels are stowed, the antennas of two arrays are interleaved, reducing the required stowage volume.