A transaction card having an opening in a metal card body, a booster antenna in the opening, and a molding material about the booster antenna. A process for manufacturing the transaction card includes forming an opening in a card body, inserting a booster antenna into the opening, and molding a molding material about the booster antenna.

A system includes a fastener and a magneto-elastic component connected to the fastener, wherein a strain level applied to the magneto-elastic component is a function of a tightness level within a range of tightness levels of the fastener. The system further includes a radio frequency identification (RFID) circuit. The system also includes an antenna electrically connected to the RFID circuit. The system includes a variable inductor circuit electrically connected to the RFID circuit and to the antenna, where an inductance exhibited by the variable inductor circuit is a function of the strain level applied to the magneto-elastic component, where a resonance response frequency of the RFID circuit is a function of the inductance exhibited by the variable inductor circuit, and where a change in the strain level results in a shift in the resonance response frequency.

A wearable device includes a first holder configured for removably receiving a first transponder and a radio frequency coupling unit. The radio frequency coupling unit includes a coupling portion and an antenna portion connected to the coupling portion. The coupling portion is configured for contactless coupling of the radio frequency coupling unit to the first transponder received by the first holder.

A system includes a fastener and a magneto-elastic component connected to the fastener, wherein a strain level applied to the magneto-elastic component is a function of a tightness level within a range of tightness levels of the fastener. The system further includes a radio frequency identification (RFID) circuit. The system also includes an antenna electrically connected to the RFID circuit. The system includes a variable inductor circuit electrically connected to the RFID circuit and to the antenna, where an inductance exhibited by the variable inductor circuit is a function of the strain level applied to the magneto-elastic component, where a resonance response frequency of the RFID circuit is a function of the inductance exhibited by the variable inductor circuit, and where a change in the strain level results in a shift in the resonance response frequency.

A jewelry head for mounting a precious or semi-precious gem to an article of jewelry, the jewelry head having a ferrimagnetic body with an inner cavity configured to accept a precious or semi-precious gem; and a near field communication circuit having a near field communication chip electrically connected to an antenna, where the antenna is wrapped around and against the ferrimagnetic body.

An antenna for a Radio Frequency Identification (RFID) transponder, including: terminals for connection with an RFID chip; two or more inductive loops; and one or more resonant structure; wherein the two or more inductive loops and the one or more resonant structure are arranged and configured such that the antenna has two or more lines of symmetry when viewed in a thickness direction of the antenna, and wherein the terminals are located within a centre portion of an overall structure of the antenna.

The invention relates to a UHF RFID transponder with an antenna and an RFID chip, wherein the antenna has a first dipole structure, a first inductive loop and an infeed point, and the first dipole, the inductive loop and the RFID chip are electrically connected to the infeed point. The purpose of the invention is to create an RFID transponder that can be tuned with reduced influence from the geometric tolerances involved in the production of the antenna. As a result, these RFID transponders are intended to be particularly suitable for attaching to glass panes, as the impedance of the antenna can be tuned to the impedance of the RFID chip with less influence from the thickness or material composition of the glass. This task is achieved in that the antenna (2) has a second inductive loop (8) and that this second inductive loop (8) is electrically connected to the infeed point (3) and connected in parallel to the first inductive loop (7).

A transaction card having an opening in a metal card body, a booster antenna in the opening, and a molding material about the booster antenna. A process for manufacturing the transaction card includes forming an opening in a card body, inserting a booster antenna into the opening, and molding a molding material about the booster antenna.

An antenna for a Radio Frequency Identification (RFID) transponder, including: an inductive loop with terminals for connection with an RFID chip; and an electromagnetically resonant structure positioned in a same plane as the inductive loop; wherein a resonant frequency of the resonant structure corresponds to a designed operating frequency in a frequency band of the RFID transponder; and wherein the electromagnetically resonant structure is electrically and physically separated from the inductive loop and capacitively coupled to the inductive loop; and the electromagnetically resonant structure includes one or more electrical discontinuities within the electromagnetically resonant structure; wherein the antenna is adapted and configured to have a non-omni directional radiation pattern and with an input impedance substantially conjugate matches an input impedance of the RFID chip at the designed operating frequency.

An example embodiment provides a sensor system including a tag unit and a readout unit. The tag unit includes a first sensor having a stretchable antenna and a stretchable resistor. The tag unit may be configured to create a sensing signal corresponding to a degree of stretching of the stretchable resistor, transmit the sensing signal to the readout unit through the stretchable antenna, and operate in a first region corresponding to a first frequency. The readout unit may be inductively coupled to the tag unit and may be configured to receive and read out the sensing signal, and operate in a second region corresponding to a second frequency. The first frequency may range 30 MHz to 50 MHz, and the second frequency may be different from the first frequency.