RFID system utilizing parametric reradiated technology
A system and method for encoding and decoding information by use of radio frequency antennas. The system includes one or more interrogator devices and RFID data tags. The RFID data tags include a plurality of antenna elements which are formed on a substrate or directly on an object. The antenna elements are oriented and have dimensions to provide polarization and phase information, whereby this information represents the encoded information on the RFID tag. The interrogator device scans an area and uses radar imaging technology to create an image of a scanned area. The device receives re-radiated RF signals from the antenna elements on the data tags, whereby the data tags are preferably represented on the image. The re-radiated RF signals preferably include polarization and phase information of each antenna element, whereby the information is utilized using radar signal imaging algorithms to decode the information on the RF data tag.
1. An RF data tag identification system comprising:
a chipless, passive RF data tag having encoded information, the RF data tag including an antenna element having predetermined phase and polarization parameters; and
at least one interrogating device configured to transmit electromagnetic radiation and receive re-radiated electromagnetic radiation from the RF data tag, wherein the at least one interrogating device is configured to decode the encoded information from at least one polarization parameter and at least one phase parameter in the received re-radiated electromagnetic radiation.
2. The system of claim 1 wherein the RF data tag further comprises a reference antenna element, wherein the reference antenna element is separated from the antenna element by at least one-half wavelength.
3. The system of claim 1 wherein at least one of the interrogating device and RF data tag is capable of moving.
4. The system of claim 1 wherein the interrogating device is configured to determine the polarization and phase parameters from the re-radiated electromagnetic radiation using a radar image signal processing algorithm.
5. The system of claim 1 further comprising a display coupled to the interrogating device which produces an image of an area scanned from the electromagnetic radiation transmitted and received, wherein the image includes at least one of a location and identity of the RF data tag.
6. The system of claim 1 further comprising a plurality of interrogating devices coupled to one another, wherein at least one interrogating device in the plurality is configured to provide RF data tag information to at least one other interrogating device in the plurality.
7. The system of claim 6 wherein a first interrogating device is configured to transmit electromagnetic radiation and the plurality of interrogating devices is configured to receive the re-radiated electromagnetic radiation substantially simultaneously.
8. The system of claim 6 wherein a first interrogating device is configured to transmit electromagnetic radiation and the plurality of interrogating devices is configured to receive the re-radiated electromagnetic radiation in a desired sequence.
9. The system of claim 6 wherein a plurality of interrogating devices is configured to transmit electromagnetic radiation sequentially and the plurality of interrogating devices is configured to receive the re-radiated electromagnetic radiation substantially simultaneously.
10. The system of claim 6 wherein a plurality of interrogating devices is configured to transmit electromagnetic radiation in a first sequence and the plurality of interrogating devices is configured to receive the re-radiated electromagnetic radiation in a second sequence.
11. The system of claim 1 wherein the RF data tag is in the far field with respect to the interrogating device.
12. The system of claim 1 wherein the RF data tag at least 3 meters away from the interrogating device.