Switched Beam Antenna Array for UHF Band RFID System

A switched beam technique applied to UHF band RFID reader is proposed. The proposed switched beam circuit composed of power divider, phase shifter, and beam controlling logic circuit is implemented on a 1x2 array antenna, and resulted in a -30 to 30 degrees beam switching range in three discrete angles. This capability not only enhances the sensing range and distance but also reduces the possible EMI interference. In addition, this array antenna can help effectively cancel or attenuate mutual interference among tags through antenna arrays directivity. These advantages provided by the antenna array greatly improve the performance of a RFID system in terms of scan efficiency and read rate, which makes RFID applications even more appealing.

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