In this work, a circularly polarized antenna array operating at 2.45 GHz has been designed. This kinds of antennas should match the gain requirement of the system in order to communicate with experimental small satellites as they are used as ground station antennas. The easiest way to prevent polarization loss between receiver and transmitter because of unstable movement of the satellite which can go up to a few kilometers is to use circularly polarized antennas. In this work a 4 element circularly polarized antenna array has been designed using sequential rotation technique. As a result it has been seen that the return loss bandwidth is about 9 percent and axial ratio bandwidth is capable of covering ISM 2.4 band. It has been seen that maximum gain of the antenna is above 8dBic.