Multi-frequency RFID apparatus and methods of reading RFID tags

摘要

A portable/handheld device is provided having a processing module configured to selectively operate a reading mode selected from a far-field mode and a near-field mode, and a directional antenna array coupled to the processing module. The directional antenna array includes a first antenna element configured to radiate electromagnetic (EM) radiation in a far-field, and a second antenna element coupled to the first antenna element. The second antenna element is configured to radiate EM radiation in a near-field. The second antenna element includes an antenna transducer configured to selectively cancel far-field EM radiation from the first antenna element. A method of reading inductively coupled radio frequency identification (RFID) tags is also provided having the steps of scanning at least one frequency band to detect a RFID tag, and selectively radiating one of a near-field electromagnetic (EM) field and a far-field EM field based on the detected RFID tag.