Method for Managing the Operation of an Object that is Able to Contactlessly Communicate with a Reader
AssigneeSTMicroelectronics International N.V.
InventorAchraf Dhayni
Life of this patent
Estimating the term…
Abstract
A method for managing the operation of an object capable of contactless communication with a reader magnetically coupled to the object includes a phase for transmission of information from the object to the reader and includes a modulation of the impedance of a load connected across the terminals of the antenna of the object. Prior to the transmission phase, a monitoring phase includes a monitoring of the level of amplitude modulation of a modulated test signal present at the antenna of the object and resulting from a test modulation of the impedance of the load and a capacitive modification of the impedance of the load if this level is lower than a threshold.
Claims22
A method for managing the operation of an object capable of contactless communication with a reader magnetically coupled to the object, the method comprising:
- performing a monitoring phase that comprises monitoring a level of amplitude modulation of a modulated test signal present at an antenna of the object that results from a test modulation of an impedance of a load connected to terminals of the antenna and a capacitive modification of the impedance of the load when the level is lower than a threshold;
- and
- performing a transmission phase that comprises transmitting information from the object to the reader by modulating the impedance of the load connected to the terminals of the antenna of the object.
A method for operating an object capable of contactless communication with a reader that is magnetically coupled to the object, the method comprising:
- generating a test modulation signal;
- modulating an impedance of a load connected to terminals of an antenna of the object, the modulating using the test modulation signal;
- determining whether a level of the impedance of the load is lower than a threshold;
- capacitively modifying the impedance of the load when the level is lower than the threshold and not modifying the impedance of the load when the level is not lower than the threshold;
- monitoring a level of amplitude modulation of a modulated test signal present at then antenna of the object that results from the modulating of the impedance of the load;
- and
- transmitting information from the object to the reader by modulating the impedance of the load connected to the terminals of the antenna of the object.
A device for managing operation of an object capable of contactless communication with a reader magnetically coupled to the object, the device comprising:
- a modulator configured to modulate an impedance of a load connected across terminals of an antenna of the object during a transmission phase during which information is transmitted from the object to the reader;
- and
- a monitor configured to carry out a monitoring phase, prior to the transmission phase, the monitoring phase comprising a test modulation of the impedance of the load, a monitoring of a level of amplitude modulation of a modulated test signal present at the antenna of the object and resulting from the test modulation and a capacitive modification of the impedance of the load if this level is lower than a threshold.
An object capable of contactless communication with a reader magnetically coupled to the object, the object comprising:
- an antenna comprising first and second terminals;
- a modulator coupled between the first and second terminals of the antenna, the modulator configured to modulate an impedance of a load connected across first and second terminals during a transmission phase during which information is contactlessly transmitted from the object to the reader;
- a processor configured to determine an envelope of a test signal and an amplitude between peaks and troughs of the envelope;
- a comparator with a first input coupled to receive the amplitude and a second input coupled to receive a threshold;
- and
- a capacitor connected to the first and second terminals of the antenna via an auxiliary switch controlled by an output signal of the comparator.
Dependencies are inferred from the claim text.