FIELD

This technology generally relates to a radiofrequency identification (RFID) systems and, in particular, to multimode millimeter wave RFID devices and methods of use thereof.

BACKGROUND

Existing radio frequency identification (RFID) systems use an integrated circuit or chip (IC) on the RFID tags attached to the items to be tracked. The IC on the RFID tags allows for the use of a device, composed of a wireless transmitter and receiver, that imparts transmitted wireless power to the IC located on the RFID tags. This class of RFID tags is designated as passive, meaning there is no local power source. The IC receives, and turns on a response to, the “read request” from the reader device. As such, the RFID tag is acting as a transponder. The IC also typically contains identification and other data that the reader then records or communicates to other parts of the RFID system.

Another type of RFID technology uses tags without ICs or chips, and is designated as a “chip-less” RFID system. One form of the chip-less RFID systems make use of millimeter wave synthetic aperture radar (SAR) technology or a radar backscatter approach to allow for communications between the reader and the chip-less RFID tags. However, the use of this form of chip-less RFID tags is limited to readers employing the SAR or backscatter technologies.

It is anticipated that RFID technology will be employed in the internet of things (IOT), which includes smart objects with local storage and/or local sensors that are connected to the Internet at large. There are two major challenges for the use of existing RFID technology in connection with IOT technology: (1) the power required for the devices, and (2) communications between the device and the Internet.

There is an entire class of IOT devices that do not require continuous power for operation, such as smart sensors that have the ability to detect their state when powered, and to communicate that state during a read. Thus, there is a need to employ readers that can also power such devices for communication.

RFID tags that would be utilized for IOT and smart sensor applications are small in size. The small size of the RFID tags prohibits using antennas on the tags. As a result, the RFID tags cannot be located in the far-field from the reader during operation. Instead, magnetic or capacitive near-field coupling must be used to power and communicate with the RFID tag. Near-field coupling results in distances of less than a few centimeters from the tag for operation, which limits the ability to employ such devices for the IOT.

SUMMARY

A radiofrequency identification (RFID) reader device includes a radiofrequency device configured to transmit and receive electromagnetic radiation through an antenna array coupled to the radiofrequency device. An RFID control computing device is coupled to the radiofrequency device and includes a memory coupled to a processor which is configured to be capable of executing programmed instructions comprising and stored in the memory to operate the radiofrequency device in a first mode to transmit a first radiofrequency beam to a scan area through the antenna array. A spatial location for one or more RFID tags located within the scanned area is determined from a radar image generated based on reflected radiofrequency beams from the scan area and re-radiated radiofrequency beams from the one or more RFID tags located within the scan area resulting from the transmission of the first radiofrequency beam to the scan area. The radiofrequency device is operated in a second mode to transmit a second radiofrequency beam to at least one of the one or more RFID tags, based on the determined spatial location of the one or more RFID tags located within the scan area, to power an integrated circuit or sensor located on and to communicate with the at least one of the one or more RFID tags.

A method includes transmitting, by a radiofrequency device, a first radiofrequency beam towards a scan area through an antenna array. A spatial location is determined for one or more RFID tags located within the scan area from a radar image generated based on reflected radiofrequency beams from the scan area and re-radiated radiofrequency beams from the one or more RFID tags located within the scan area resulting from the transmission of the first radiofrequency beam to the scan area. A second radiofrequency beam is transmitted to at least one of the one or more RFID tags, based on the determined spatial location of the one or more RFID tags located within the scan area.

The present technology advantageously provides a system that has dual mode capability for identification and communication with various types of RFID tags. The system can be implemented using extremely high frequency wireless technology that is advantageously designed to image and locate various types of RFID tags and smart sensors using synthetic aperture radar (SAR) while in a wide antenna beam pattern mode, and then shift to a narrow, beam steered mode for powering and communicating with the RFID tags or smart sensors. The system has the capability to operate in the radar imaging mode to locate various types of chip-less and chipped RFID tags, as well as Internet of Things (IOT) devices, with a high degree of accuracy. Once the tags or devices are located, the system has the additional capability of powering and communicating with the RFID tags in the far-field.

The system can be employed and provide the aforementioned advantages in any usage requiring RFID tag or sensor operation, including, but not limited to: inventory identification; asset management tracking and shipping container location; vehicular access control (e.g. toll ways); moving vehicle identification; healthcare identification and tracking of patients, drugs, equipment and personnel identification, tracking and monitoring of personnel and equipment for security purposes; identification of luggage and packages at airports; systems for locating lost objects (e.g. keys, files, golf balls, clothing articles), although any other uses, including uses for the IOT are contemplated.

