Provided is a system, method, and apparatus for tracking a body. The method includes communicating at least one activation signal to each RF transponder of a first array and a second array, receiving a plurality of response signals from the first array and the second array, the plurality of response signals comprising a response signal for each RF transponder of the first array and the second array, determining a difference in distances between the antenna and each RF transponder of the first array and each transponder of the second array based at least partially on at least one corresponding response signal of the plurality of response signals, and determining a relative location of the first portion of the body and the second portion of the body.

In a data transmission terminal, a processor is configured to determine whether or not a change greater than or equal to a predetermined amount has occurred between values represented by multiple pieces of first sensor data stored on a memory when a state of communication has shifted from a normal state to a disconnected state. The processor is configured to classify the multiple pieces of the first sensor data as changed data and unchanged data when the processor determines that the change has occurred. The processor is configured to transmit the changed data to the external terminal by using a communicator. The processor is configured to transmit the unchanged data to the external terminal by using the communicator after the changed data are transmitted to the external terminal.

In a data transmission terminal, a processor is configured to determine whether or not a change greater than or equal to a predetermined amount has occurred between values represented by multiple pieces of first sensor data stored on a memory when a state of communication has shifted from a normal state to a disconnected state. The processor is configured to classify the multiple pieces of the first sensor data as changed data and unchanged data when the processor determines that the change has occurred. The processor is configured to transmit the changed data to the external terminal by using a communicator. The processor is configured to transmit the unchanged data to the external terminal by using the communicator after the changed data are transmitted to the external terminal.

A notification response circuit includes a reception coil, a characteristic variable circuit connected to the reception coil, and a switch control circuit. The reception coil is configured to generate a current based on an external electromagnetic field. The characteristic variable circuit includes at least two circuits of a variable capacitor circuit, a voltage output circuit, and a variable resistor circuit. The variable capacitor circuit is configured to change a capacitance. The voltage output circuit is configured to change a voltage value between a pair of connection lines disposed between the reception coil and the voltage output circuit according to a voltage value of a reference voltage. The variable resistor circuit is configured to change a resistance value. The switch control circuit selectively switches any of the at least two circuits and performs control to change impedances of the reception coil and a circuit part connected to the reception coil.

A notification response circuit includes a reception coil, a characteristic variable circuit connected to the reception coil, and a switch control circuit. The reception coil is configured to generate a current based on an external electromagnetic field. The characteristic variable circuit includes at least two circuits of a variable capacitor circuit, a voltage output circuit, and a variable resistor circuit. The variable capacitor circuit is configured to change a capacitance. The voltage output circuit is configured to change a voltage value between a pair of connection lines disposed between the reception coil and the voltage output circuit according to a voltage value of a reference voltage. The variable resistor circuit is configured to change a resistance value. The switch control circuit selectively switches any of the at least two circuits and performs control to change impedances of the reception coil and a circuit part connected to the reception coil.

An RFID label includes: a substrate; a dipole antenna formed of a metal foil so as to have a predetermined antenna length and a predetermined antenna width, the dipole antenna being arranged on a surface of the substrate; an IC chip connected to the dipole antenna; and a separator temporarily adhered to an adhesive agent overlaid on the surface of the substrate on which the dipole antenna is arranged, wherein a tear off line cuts through the substrate and the dipole antenna, in at least a part of the dipole antenna, so as to extend along an antenna length direction and so as to be superimposed with the part of the dipole antenna.

The application relates to methods and a driver for communication with a transponder, in particular a driver for installation in a motor vehicle and for communication with a mobile transponder for a vehicle access and/or start system of a motor vehicle, wherein the driver is designed so that, after a first transmission at a first transmission frequency and after driver-side reception of a response of a transponder at the transponder resonance frequency thereof, and after driver-side determination of the response frequency of the response using a frequency detection apparatus,
said response frequency is set, in particular by changing transmission pauses, at the driver as the second transmission frequency, corresponding to the measured transponder resonance frequency, at which the driver is then intended to transmit, wherein the driver has a resonant circuit (2, 3, 4), which has a higher driver resonant frequency than the mentioned first transmission frequency and than the mentioned second transmission frequency of the driver.

The application relates to methods and a driver for communication with a transponder, in particular a driver for installation in a motor vehicle and for communication with a mobile transponder for a vehicle access and/or start system of a motor vehicle, wherein the driver is designed so that, after a first transmission at a first transmission frequency and after driver-side reception of a response of a transponder at the transponder resonance frequency thereof, and after driver-side determination of the response frequency of the response using a frequency detection apparatus,
said response frequency is set, in particular by changing transmission pauses, at the driver as the second transmission frequency, corresponding to the measured transponder resonance frequency, at which the driver is then intended to transmit, wherein the driver has a resonant circuit (2, 3, 4), which has a higher driver resonant frequency than the mentioned first transmission frequency and than the mentioned second transmission frequency of the driver.

A wireless tag system including a tag signal antenna configured to receive a tag signal transmitted from a wireless transmission tag; and a communication area shaping antenna configured to transmit a reception area shaping signal for narrowing an area in which the tag signal antenna can communicate with the wireless transmission tag.

A transmission circuit includes a first impedance circuit, a second impedance circuit, and a phase shifter. Each of the first impedance circuit and the second impedance circuit includes a register circuitry and a control circuitry that controls a resistance value of the register circuitry. The first impedance circuit is configured to output a reflected wave of an input signal to the phase shifter. The phase shifter is configured to shift a phase of the input signal to input the input signal to the first impedance circuit and to shift a phase of the reflected wave of the input signal output from the first impedance circuit to output the reflected wave to the combiner circuit. The second impedance circuit is configured to output the reflected wave of the input signal to the combiner circuit.