The problem to solve is how to extend the operating range of small stackable RFID tags when they are placed in an undesirable orientation. Disclosed is an RFID tag that operates in two modes whereby in a first mode the tag has a short range and in a second mode the tag has a long range. The tag is converted from the first mode short range device into the second mode long range device by placing it close to a coupling device. That is in the second mode the tag becomes a two part RFID tag system (1400) capable of communicating with an interrogator antenna (1407).

An antenna (100) for an RFID reading apparatus is provided having at least one single CLL antenna (10), wherein a single CLL antenna (10) is an antenna that has an inner antenna loop (12) and a capacitively loaded antenna loop (14) which surrounds the inner antenna loop (12) and into which a capacitance (16 is introduced. In this respect, the antenna (100) has a plurality of single CLL antennas (10a-d) that are differently oriented and has a feed circuit (26) to operate the single CLL antennas (10a-d) for generating a circular polarization with a respective phase offset.

An RFID-based sensing method including receiving, from an RFID tag with a tuning circuit when the tuning circuit is arranged in a first state, a first RF signal; and receiving, from the RFID tag when the tuning circuit is arranged in a second state, a second RF signal. The tuning circuit is arranged to affect or facilitate impedance matching of an antenna and an integrated circuit of the RFID tag. The method also includes processing the first and second RF signals received to determine respective differences in two or more properties of the first and second RF signals received; and determining, based on the processing, a status associated with an environment in which the RFID tag is arranged.

A Radio Frequency Identification (RFID) tag is disclosed. The RFID tag includes an antenna to receive a high frequency signal, a capacitor bank coupled with the antenna, a charge pump coupled with the antenna configured to convert the high frequency signal to a direct current (DC) signal, an envelope detector to measure peak voltage of the high frequency signal and a detector to compare an output of the charge pump and an output of the envelope detector. The RFID tag also includes an impedance tuning circuit coupled with the charge pump and the envelope detector configured change a capacitance of the capacitor bank based on an output of the detector and the envelope detector.

A Radio Frequency Identification (RFID) tag is disclosed. The RFID tag includes an antenna to receive an input AC signal and a tuning system coupled with the antenna to optimize signal strength of the input AC signal. The tuning system includes a charge pump rectifier. A diode rectifier is included and is coupled with the antenna to receive the input AC signal after the tuning system optimizes the signal strength by tuning input impedance of the antenna.

A noncontact communication medium includes a processing circuit that is mounted on a substrate on which an antenna coil is formed, and has an internal capacitor, and an external capacitor that composes a resonance circuit configured to resonate at a predetermined resonance frequency, along with the internal capacitor and the antenna coil. A method for manufacturing a noncontact communication medium includes measuring a temporary resonance frequency in a state in which the external capacitor is not connected to the processing circuit and in a state in which the processing circuit is connected to the antenna coil, and deciding capacitance of the external capacitor based on a degree of difference between a reference resonance frequency in a case where the noncontact communication medium performs communication with an outside through a magnetic field and a temporary resonance frequency.

Radiofrequency device with adjustable LC circuit comprising an electrical and/or electronic module. The invention relates to a communication device with a radio-frequency chip, said device comprising—an insulating support layer, —an electrical and/or electronic radiofrequency circuit on said insulating layer, said circuit comprising plates of an adjustable capacitor and/or an antenna spiral with adjustable inductance, —at least one element for adjusting a tuning frequency of the radiofrequency circuit. The device is distinguished in that said plates and/or spiral are included in an electrical and/or electronic chip card module, and in that said adjusting element connects an intermediate point of the spiral so as to decrease the available inductance and/or splits or links the plates so as to adjust the capacitance.

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 portable data carrier comprises a first electrical oscillating circuit, which includes a first antenna coil and a first electrical load, and at least one second electrical oscillating circuit, which comprises a second antenna coil and a second electrical load. The first antenna coil and the second antenna coil are geometrically arranged relative to each other such that there is no mutual inductance between the first antenna coil and the second antenna coil.

Aspects of the present disclosure relate to methods and systems for laser turning and attaching RFID tags to products. Such methods and systems may include a memory and a processor coupled to the memory. The methods and systems may include determining a characteristic of a conductive trace on a substrate to be incorporated into an item to configure a tag performance in view of at least one of a dielectric property or a tuning property of the item. The methods and systems may further include a laser to alter the conductive trace on the substrate to have the characteristic to define an antenna for the tag. The methods and systems may further include an attaching device configured to attach a communications enabled device to the substrate so as to form an electrical connection between the communications enabled device and the antenna to form the tag.