An RFID tag is provided that includes an insulator film, an antenna with an antenna conductor pattern disposed on the insulator film, and an RFIC module mounted on the insulator film. The RFIC module includes an RFIC and an impedance matching circuit. The impedance matching circuit includes a first coil and a second coil. Main planes of magnetic flux loops generated in the vicinities of the first coil and the second coil by the antenna are not parallel to main planes of magnetic flux loops generated in the first coil and the second coil.

An RFID tag is provided that includes an RFIC chip having a first connection terminal and a second connection terminal, a first electrode electrically connected to the first connection terminal of the RFIC chip, a capacitance element connected in series to the first electrode and the RFIC chip, and short-circuit parts connecting the first electrode and a ground at an intermediate position of an electrical length of the first electrode. Moreover, the electrical length of the first electrode is a half of a wavelength of a communication frequency of the RFIC chip, the first connection terminal of the RFIC chip is connected to the first electrode at a position within one third of the electrical length from an end portion of the first electrode, and the second connection terminal of the RFIC chip is connected to the ground.

An interference suppression apparatus suppresses electromagnetic field interference produced by an RFID tag. The interference suppression apparatus includes a power supply circuit, an antenna that is connected to the power supply circuit, a clock that is connected to the power supply circuit, and a load adjuster that is connected to the power supply circuit. The clock generates an output in which a time constant is adjusted to be longer than a communication time of the RFID tag. The load adjuster changes a characteristic of the antenna based on the output from the clock.

A card core includes a body defining a cutout and a discontinuity. The cutout includes an opening in the body defined by an edge and the discontinuity includes a channel defined by the body extending from an outer surface of the body to the cutout. At least one circuit element is positioned within the cutout. The cutout defines a size and geometry such that a gap is defined between the at least one circuit element and the edge to electromagnetically isolate the at least one circuit element from the body.

Techniques, systems, and devices are disclosed for the design and manufacturing of a radio-frequency identification (RFID)-enabled license plate. In one aspect, a proposed RFID-enabled license plate includes a metal plate and a RFID assembly integrated with the metal plate. The RFID assembly further includes a front cover attached to a first side of the metal plate and a back cover attached to a back side of the metal plate opposite to the front cover, and the front cover and the back cover substantially overlap with each other. The RFID assembly additionally includes a RFID tag sandwiched between the front cover and the back cover and is affixed to at least one of the front cover and the back cover. As such, the RFID tag is substantially tamper-proof.

An RFID module is disposed at a position where the RFID module is electromagnetically coupled to the conductor. An RFIC receives power induced by receiving an electromagnetic wave for power reception to output a transmission signal. A power reception coupling unit is electromagnetically coupled to the conductor to receive power. A transmission coupling unit is electromagnetically coupled to the conductor to output a transmission signal to the conductor.

A card core includes a body defining a cutout and a discontinuity. The cutout includes an opening in the body defined by an edge and the discontinuity includes a channel defined by the body extending from an outer surface of the body to the cutout. At least one circuit element is positioned within the cutout. The cutout defines a size and geometry such that a gap is defined between the at least one circuit element and the edge to electromagnetically isolate the at least one circuit element from the body.

Systems and methods for integrating tags with items. The methods comprise: dynamically determining a length of each metal thread to be incorporated into or trace to be disposed on a item to optimize tag performance in view of dielectric and tuning properties of the item. In the metal thread scenarios, the methods also involve: creating a metal thread having the length that was dynamically determined; and sewing the metal thread into the item being produced to form an antenna for a first tag. In the trace scenarios, the methods also involve forming the trace on the item being produced to form an antenna for a first tag. Next, at least a communications enabled device is attached to the item so as to form an electrical coupling or connection between the communications enabled device and the at least one antenna.

A “core” or “inlay” for a smartcard may comprise a first metal layer and a second metal layer, and may be formed by folding a single metal layer upon itself. A module cavity may be formed in the first metal layer by laser cutting, prior to laminating. An adhesive layer may be disposed between the two metal layers. A module opening may be formed in the second metal layer by milling, after laminating the first metal layer to the second metal layer. A slit in a metal layer may extend from an outer edge of the layer to the cavity or opening, thereby forming a coupling frame. The slit may have a termination hole at either end or at both ends of the slit. The slits of two metal layers may be positioned differently than one another.

Example embodiments relate to radio-frequency identification (RFID) tags for liquid monitoring. An example RFID tag includes an antenna configured to communicate with an RFID reader. The antenna includes a radiating plane. The antenna also includes a ground plane. The RFID tag is attachable to a container. A reactance associated with the antenna is modifiable based on a temperature and a volume of a liquid within the container and adjacent to the ground plane. The RFID tag also includes an integrated circuit that includes a memory. The integrated circuit is configured to modulate the antenna in response to an RFID signal from the RFID reader based on the reactance associated with the antenna.