Radio frequency identification (RFID) tag having multiple antennas

A Radio Frequency Identification (RFID) tag having a plurality of antennas, the tag comprising:

• a first antenna and a second antenna each configured to backscatter respective received Radio Frequency (RF) signals;
• a modulator configured to comprises a first unit modulation circuitry configured to be electrically connected to the first antenna to vary power of an uplink signal backscattered through the first antenna, and a second unit modulation circuitry configured to be electrically connected to the second antenna to vary power of an uplink signal backscattered through the second antenna;
• and
• a digital and memory circuitry, which once the RF signals are received through the first and the second antennas, is configured to generate a series of encoding signals with identification information to be transmitted being encoded therein, and to output the generated signals,
• wherein the modulator operates such that the power of the uplink signal backscattered through each of the first and the second antennas is equal regardless of types of the encoding signals.