Systems and methods for interrogator multiple radio frequency identification enabled documents
View Patent ↗A multi-document read-write station provides the ability to read/write to a stack of Radio Frequency Identification (RFID) tags within a small area. Specifically, the station provides the ability to read from and write to a tall stack of RFID tagged sheets with the RFID tags stacked one on top of the other. The station and capability described herein is the result of and comprises several components including a closed chamber comprising a document slot, an antenna system, and a power management system.
1. A system for communicating with a plurality of Radio Frequency Identification (RFID) tags affixed to a plurality of documents, comprising:
a Radio Frequency (RF) radiating antenna for communicating via RF signals with the plurality of RFID tags;
a chamber comprising conductive walls, the chamber configured to maintain a high RF field strength; and
a slot within the chamber, the slot comprising no-conductive walls and an angled stop wall, the slot configured to hold the plurality of documents in a location such that the plurality of RFID tags are exposed to the high RF field strength and to create an offset between the RFID tags.
2. The system of claim 1 , wherein the chamber is configured to resonate at an operational frequency for the system.
3. The system of claim 1 , wherein the radiating antenna is configured to receive RF signals from the plurality of RFID tags, and wherein the radiating antenna is configured to receive harmonic signals from the plurality of RFID tags.
4. The system of claim 1 , further comprising a receive antenna configured to receive RF signals from the plurality of RFID tags, wherein the receive antenna is separate from the radiating antenna and positioned close to the plurality of RFID tags.
5. The system of claim 1 , wherein the receive antenna is configured to receive harmonic signals from the plurality of RFID tags.
6. The system of claim 1 , further comprising a plurality of radiating antennas located at different locations within the chamber and around the slot.
7. The system of claim 1 , configured to use multiple frequencies for communication with the plurality of RFID tags.
8. The system of claim 1 , wherein a transmit power for RF signals generated by the radiating antenna are cycled within a range.
9. The system of claim 1 , wherein the transmit power for signals generated by the radiating antenna is determined based on the number of documents present as determined by a numbering mechanism.
10. The system of claim 1 , further comprising detuning pads positioned on the top or bottom of the slot.