In this paper, we presented the synchronization module between RF shower system and RFID Reader to extend interrogating range on Mobile RFID system, Costas Loop and FPLL(Frequency/phase Lock Loop) were used. We achieved compromised range of 3MHz locking frequency, 1ms locking time and figured out remarkable Hopping frequency of the Reader. The prototype of the new designed RFID system has been tested with ISO18000-6 type-B Tag. The read range between designed RFID Reader and Tag has been measured, it increased triple times by adjusting the Shower system output level.