Systems and methods of bi-directional communication between an electronic card and a touchscreen device is described. The method may include modulating an electrostatic field of the touchscreen device using touch communication channels; receiving visible light signals from the touchscreen device in response to the modified electrostatic field via one or more optical communication channels; ranking, by the electronic card, the optical communication channels according to the signal quality received from each optical communication channel; selecting at least one optical communication channel as preferred optical communication channel based on the ranking; and using the preferred optical communication channel and the touch communication channels for subsequent bi-directional communication.

A tag indicating an attribute of the tag by an electromagnetic wave reflection characteristic, the tag including a substrate (11), and a conductor pattern layer (12) formed on the substrate (11) and having first and second slots (13a) and (13b) disposed adjacent to each other, in which the first slot (13a) constitutes a first resonance element (13Qa) having a resonance frequency at a first frequency, the second slot (13b) constitutes a second resonance element (13Qb) having a resonance frequency at a second frequency higher than the first frequency, and when irradiation with the electromagnetic waves is performed, a Q value of a resonance peak appearing at the first frequency is higher than a Q value of a resonance peak appearing at the first frequency when the first slot (13a) alone constitutes a resonance structure of the tag.

An identification device includes a first metal layer patterned into a planar coil winding and a second metal layer electrically connected to the first metal layer. The first metal layer is operable to provide a circuit inductance. The second metal layer is patterned to provide one or more overlapping areas with the first metal layer. The second metal layer is operable to provide a circuit capacitance. The identification device includes a dielectric layer separating the first metal layer and the second metal layer.

A disclosed component may include at least one split-ring resonator, which may be embedded within a material. The split ring resonator may be formed from a three-dimensional (3D) monolithic carbonaceous growth and may detect an electromagnetic ping emitted from a user device. The split ring resonator may generate an electromagnetic return signal in response to the electromagnetic ping. The electromagnetic return signal may indicate a state of the material in a position proximate to a respective split ring resonator. In some aspects, the split-ring resonator may resonate at a first frequency in response to the electromagnetic ping when the material is in a first state, and may resonate at a second frequency in response to the electromagnetic ping when the material is in a second state. A resonant frequency of the 3D monolithic carbonaceous growth may be based on physical characteristics of the material.

Present invention is a wireless device comprising a Van Atta array, said Van Atta array comprising a plurality of antenna pairs, each of said antenna pairs comprising two antenna elements electrically coupled by a signal path of pre-determined length. The wireless device further comprises a measurement unit, said measurement unit is adapted to perform electrical measurements between two measurement points. One of said two measurement points is located at a first pre-determined location on the signal path of one of the antenna pairs, and the other of said two measurement points is located on a second pre-determined location on the signal path of one of the other antenna pairs. The present invention is also a method for retro-reflection of an incident wave using a plurality of antenna pairs.

Inductive identification systems and methods are described. The system may include an inductive detector configured to identify objects having inductive identifiers. An inductive detector may include conductive coils and inductance readout circuitry for measuring an inductance of each coil. An inductive identifier may include a conductive pattern configured to induce a desired inductance in the coils of the inductive detector. An inductive identifier may include a film having openings, each opening configured to be disposed over a corresponding coil to induce differing inductance changes in the corresponding coils. A pattern of inductance values may be determined and used to identify the object. The detector may be implemented in a cassette recess of an infusion pump system. The inductive identifier may be disposed on a pump cassette configured to be received in the cassette recess and identified based on an inductive interaction between the inductive detector coils and the inductive identifier.

The present invention relates to a radio frequency identification (personalized) device (RFID) without chip, in particular to a RFID tag (personalized) without chip, also referred to as chipless RFID tag.

Micro-Electro-Mechanical System (MEMS) tags having high and low resonant frequencies are used to detect the cured or uncured state of wellbore cement. The MEMS tags may be added to wellbore cement, and pumped downhole. An interrogation tool emits a signal at one or both of the resonant frequencies which, in turn, interacts with the MEMS tags to produce a response signal. Since uncured cement has a high attenuation, only the lower resonant frequency response signal is sensed by an interrogation device, thus indicating the cement remains uncured. When the cement cures, its conductivity drops and the attenuation of the higher resonant frequency response signal drops also, thus allowing that signal to be detected by the interrogation device and indicating the cement has cured.

An encoder includes a layered structure including a metal plate, a dielectric layer arranged on the metal plate, and a plurality of metallic components arranged on the dielectric layer to form a pattern of resonant circuits. The encoder includes an emitter to emit a waveform of a resonant frequency to the layered structure and a receiver to measure amplitudes of the waveform reflected from the layered structure. The processor operatively connected to a memory storing data relating positions of the emitter with amplitudes of the reflected waveform determines a position of the emitter from the measurements of the amplitudes based on the data. The encoder includes an output interface to render the position of the emitter.

Systems and methods of bi-directional communication between an electronic card and a touchscreen device is described. The method may include modulating an electrostatic field of the touchscreen device using touch communication channels; receiving visible light signals from the touchscreen device in response to the modified electrostatic field via one or more optical communication channels; ranking, by the electronic card, the optical communication channels according to the signal quality received from each optical communication channel; selecting at least one optical communication channel as preferred optical communication channel based on the ranking; and using the preferred optical communication channel and the touch communication channels for subsequent bi-directional communication.