Em Microelectronic-marin Sa

Goran Stojanovic

Christian Lamothe

Jiri Kolman

Paul Muller

Thomas Coulot

Tomas Marek

Jan Bicak

Juergen Riedel

Nicolas Pillin

Tony Ghueldre

Frédéric Sacksteder

Catalin Lazar

Frederic Sacksteder

Jürgen Riedel

A method provides a tamper loop status of a radio-frequency transponder to a reader. The transponder communicates with the reader at a first frequency according to a first communication protocol. The transponder includes a first non-volatile memory for storing a first set of data of the first communication protocol. The first memory includes a user memory having two portions and each portion includes a data item specific to a status of the tamper loop. The method is performed by the transponder after receiving a request according to the first protocol to read the user memory and includes generating a logical view of the user memory, the logical view including only one of the two portions that is selected according to a value of a binary parameter representative of a status of the tamper loop. The method also includes providing the logical view to the reader via the first protocol.

Method for providing a reader with a tamper loop status of a radio-frequency transponder

The Dual frequency HF-UHF identification device comprises a RFID integrated circuit with a power supply having a HF part, formed by a HF rectifier connected to a HF antenna, and a UHF part formed by a UHF rectifier connected to a UHF antenna. The RFID integrated circuit comprises a storage capacitor common to the HF and UHF parts of the power supply. The HF rectifier output and the UHF rectifier output are both continuously connected to the supply terminal of the common storage capacitor. Further, the supply terminal of the common storage capacitor is connected, on the one hand, to the output of the HF rectifier through a diode arranged so as to block a current from said supply terminal to the HF rectifier output and, on the other hand, directly to the output of the UHF rectifier formed by a charge pump.

Dual frequency HF-UHF identification device

A dual communication frequency RFID circuit includes a logic unit for processing data signals received or transmitted at a first frequency by a first antenna or at a second frequency by a second antenna, and a unit for managing the state of a tamper loop linked to the integrated circuit by two connection terminals. The management unit includes a first low-pass filter linked to a first connection terminal, a second low-pass filter linked to a second connection terminal, a current source for supplying a current through the first low-pass filter, a switch linked at the output of the second low-pass filter, and a first inverter connected between the current source and the first low-pass filter for supplying an output signal for the state of the tamper loop to the logic unit.

Dual communication frequency RFID circuit equipped with a tamper-evident loop

A receiver unit for a radio frequency (RF) tag is provided, including a first input terminal and a second input terminal each being connected to an antenna; a communication stage configured to demodulate and/or to modulate an incoming signal in the communication stage; and a power stage including a voltage converter circuit being configured to supply power to the receiver unit, and a regulation circuit being configured to limit an output voltage of the voltage converter circuit, wherein the regulation circuit includes a regulator circuit being configured to determine a first current value and a second current value, the second current value being a current value provided in addition to the first current value, and, if the second current value exceeds a predetermined threshold value, to supply a control signal to a limiter circuit configured to limit an input voltage of the voltage converter circuit.

Receiver unit for an RF tag

The dual frequency RF identification device comprises an HF antenna for receiving an HF electromagnetic field, an HF interface, an UHF antenna for receiving an UHF electromagnetic field, an UHF interface, non-volatile memory means formed by a first non-volatile memory and a second non-volatile memory. The first non-volatile memory can be in an active state without the second non-volatile memory being powered and consumes substantially more power than this second non-volatile memory. The first non-volatile memory comprises all data needed for a device configuration allowing this device to carry out at least a communication mode of an UHF protocol, this communication mode having access to the first non-volatile memory but not to the second non-volatile memory. The first non-volatile memory further comprises all attributes needed for a configuration of this communication mode.

Dual frequency HF-UHF identification device, in particular of the passive type

An envelope detector circuit, suitable for use in RFID tags, includes a voltage doubler circuit and a biasing voltage generating circuit which comprises components matched respectively to rectifying components of the voltage doubler circuit. A rectifying component of this voltage doubler circuit is formed by a transistor controlled by the biasing voltage generating circuit which provides a biasing voltage to a control gate of this transistor, the biasing voltage generating circuit being arranged so as to permit a determined forward biasing current to flow through the transistor and further rectifying elements of the voltage doubler circuit. This embodiment provides fast, highly sensitive detection of envelope waveforms in input signals. Thanks to the matched rectifying components, efficiency variations due to variations in manufacturing process can be eliminated. The envelope detector circuit is further arranged for maintaining a stable detection independent of variations in temperature.

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Neuchatel, Switzerland

Goran Stojanovic