Embodiments of the present invention provide RFID systems having a centralized frequency source and controller. The centralized frequency source generates a reference signal, having a frequency below the RF band of interest, which is transmitted to a plurality of reader nodes. The centralized controller generates and transmits data to the plurality of reader nodes. At each reader node, the reference signal is converted to an RF carrier signal that is modulated and transmitted within corresponding read field of the reader node. This modulated RF carrier signal may interrogate and communicate with one or more RFID tags within this read field. The RF carrier signal may also be held constant to enable communication from RFID tags to the reader node, which is subsequently transmitted back to the centralized controller or processor.