A system comprising synchronization circuitry, a first interrogator, and a second interrogator. The first interrogator includes a transmit antenna; a first receive antenna, and circuitry configured to generate, using radio-frequency (RF) signal synthesis information received from the synchronization circuitry, a first RF signal for transmission by the transmit antenna, and generate, using the first RF signal and a second RF signal received from a target device by the first receive antenna, a first mixed RF signal indicative of a distance between the first interrogator and the target device. The second interrogator includes a second receive antenna, and circuitry configured to generate, using the RF signal synthesis information, a third RF signal; and generate, using the third RF signal and a fourth RF signal received from the target device by the second receive antenna, a second mixed RF signal indicative of a distance between the second interrogator and the target device.

An electrosurgical return electrode configured for operable association with a transponder detection unit. The return electrode includes a conductive element having an aperture array configured to allow passage of a magnetic, electric, or electromagnetic interrogation signal from the transponder detection unit through the conductive element and through the return electrode. The return electrode is positionable over a transponder detection unit such that the return electrode may be placed upon the transponder detection unit and a patient may be positioned upon the return electrode. The return electrode enables the detection of a transponder located on, within, and/or near the patient without the need for repositioning the patient relative to the return electrode and without the need for positioning an ancillary transponder reader or transmitter above the patient.

An RFID-enabled storage container and systems and methods for assembly and use thereof. The RFID-enabled storage container may include adjustable shelving with built-in antennas, such that the shelving may be customized as may be needed. The system may include a storage container, an inventory management system, and one or more point of use terminals. The storage container may identify and check inventory stored thereon, and provide such information to the inventory management system. The storage container may notify the inventory management system when a product is no longer detected within its inventory, and the inventory management system may monitor the one or more point of use terminals to determine if the undetected product has been used at one of the point of use terminals. The inventory management system may also predict inventory needs as well as maintain age and other data for inventory and provide feedback via an illumination indication.

An antenna device includes a feed coil connected to a feed circuit, and a coil antenna disposed near the feed coil. A ferrite sheet, in which a magnetic loss term in a usable frequency band is relatively large, is provided between the feed coil and the coil antenna. The feed coil and the coil antenna are magnetically coupled to each other via the ferrite sheet. With this configuration, signal transmission efficiency between the feed coil and the coil antenna is enhanced.

A UHF-RFID antenna having a central segmented loop surrounded by passive dipole structures provides shaping of the electric and magnetic fields to reduce the number of false positive reads by a UHF-RFID reader at a point of sale.

A system and method for monitoring the inventory of a medical storage container that has a required inventory of medical articles. An enclosure is used to isolate, scan, and take an inventory of a tray or other container of medical articles each of which has an RFID tag. The enclosure having a size smaller than the size needed for a resonant frequency at the RFID frequency of operation of the tags. An injection device is used to create a robust electromagnetic field standing wave of constructive interference in the enclosure and a program compares the scanned present inventory of the tray to the required inventory database and indicates any differences. Expired and recalled articles are identified.

Systems and methods for tracking a subject using radio-frequency identification (RFID). In an embodiment, an antenna array comprising a plurality of articulating brackets and a plurality of antennas is provided. Each of the articulating brackets is configured to move one of the plurality of antennas into a plurality of positions, and each of the antennas is configured to receive a RFID signal. In addition, a processor receives RFID data based on RFID signals received by the antennas of the antenna array, and determines a trajectory of a subject based on the RFID data. Based on the determined trajectory of the subject, the processor controls one or more of the articulating brackets to move one or more of the antennas into a position to track the subject.

An antenna device which includes an antenna structure constituted of a conductive material layer formed on a dielectric planar substrate, and configured to communicate with a radio frequency identification tag, wherein the antenna structure includes an active electrode group, a passive electrode group, and a loop type plane electrode which connects the active electrode group to feeding points, an electromagnetic field is produced between the active electrodes and the passive electrodes by electromagnetic induction, an electromagnetic field which is different from the electromagnetic field in phase is produced between the loop type plane electrode and the passive electrodes by an electromagnetic mutual interference, and electromagnetic field density on the dielectric planar substate is raised while forming magnetic fields with different phases within the same electromagnetic field.

An antenna device of the present invention includes, in one aspect: a patch antenna having a resonant frequency at a first frequency; and a loop antenna having a resonant frequency at a second frequency that is different from the first frequency. A loop length of the loop antenna is such that standing waves are generated in the loop antenna when the loop antenna receives radio waves of the first frequency, and the patch antenna is disposed so as to magnetically couple with the loop antenna.

An RFID antenna device (10) for emitting and/or receiving circularly polarised electromagnetic radiation, comprising a radiator unit (12) which has a radiator network (14) with multiple at least partially curved radiator portions (16) and an auxiliary antenna (20) which is galvanically isolated from the radiator network (14) and is inductively or capacitively coupled to the radiator network (14), a supply network unit (22) having a power division portion (26) with a device port and having at least one delay portion (28) which is electrically conductively connected to the power division portion (26) and is electrically conductively connected to the radiator portions (16), wherein the auxiliary antenna (20) is centrally located between the radiator portions (16). Further, an RFID sensor device comprising such an RFID antenna device (10).