Abstract: Tuning an antenna circuit of an actively transmitting tag to a frequency of an interrogator carrier signal after the tag was inserted into a host device is accomplished by detecting presence of the interrogator carrier signal at a location of the actively transmitting tag and hereafter setting capacitances of capacitors and/or inductances of coils comprised in said antenna circuit in a way that resonance of said antenna circuit is established while the antenna circuit is excited by a magnetic field of said interrogator carrier signal. This allows automatic tuning of an antenna circuit of an actively transmitting tag after it was inserted together with a miniature card into a host device, such as a mobile telephone, personal digital assistant, tablet PC and similar devices.

Abstract: Tuning an antenna circuit of an actively transmitting tag to a frequency of an interrogator carrier signal after the tag was inserted into a host device is accomplished by detecting presence of the interrogator carrier signal at a location of the actively transmitting tag and hereafter setting capacitances of capacitors and/or inductances of coils comprised in said antenna circuit in a way that resonance of said antenna circuit is established while the antenna circuit is excited by a magnetic field of said interrogator carrier signal. This allows automatic tuning of an antenna circuit of an actively transmitting tag after it was inserted together with a miniature card into a host device, such as a mobile telephone, personal digital assistant, tablet PC and similar devices.

Abstract: When communicating with a traditional interrogator of passive smart tags, an actively transmitting smart tag of the invention, even within a data frame being transmitted, observes a first phase (?i) being a phase of a voltage induced in a tag's antenna by an interrogator's high-frequency carrier signal and transmits wave packets in that it excites the antenna with a voltage having a phase (?t), which is always set at the beginning of transmission of each said wave packet shifted with respect to said first phase (?i) by the same phase angle (??). At ??=180° an amplitude of voltage across an interrogator's antenna, when some of said wave packets influence this antenna, attains the largest attainable interference rise. Miniature actively transmitting smart tags are enabled to wirelessly communicate with said traditional interrogator and a communication range of pocket-sized tags is herewith increased.

Abstract: The electronic circuit is intended to form with an antenna a responder that operates without resetting to zero when the power supply of the electronic circuit is switched on (without POR). To increase efficiency and reduce the costs of testing a plurality of such integrated circuits in a wafer, means are provided that allow the logic circuit (8) to be reset to zero during such a test by electrical contact with the pads (P1, P2) of each circuit by using two extractors (12 and 14) of clock signals (CL1 and CL2) connected to the inputs of a generator (20) of a zero reset signal (SR). The state of the generator is essentially given by the difference in pulses received from the two clock signal extractors. As soon as the state of the generator corresponds to a value equal to or greater than a predefined integer, the logic circuit is reset to zero, which never occurs with the responder receiving an interrogation signal of a reader.

Abstract: An amplitude of a carrier signal at an output of an impedance matching block is measured as a first amplitude value. A value of the signal amplitude at the output of the impedance matching block is calculated as a second amplitude value that a signal resulting from amplitude modulation with said modulation factor from said carrier signal should assume, said carrying signal having an amplitude with the first amplitude value. A setting of a transmitter is changed to decrease the carrier signal amplitude at the output of the impedance matching block. An amplitude of a new carrier signal at the output of the impedance matching block is measured as a new amplitude value. The transmitter setting keeps changing so many times until the new amplitude value is equal to or lower than said second amplitude value or within a predetermined tolerance range around said second amplitude value.

Abstract: When communicating with a traditional interrogator of passive smart tags, an actively transmitting smart tag of the invention, even within a data frame being transmitted, observes a first phase (?i) being a phase of a voltage induced in a tag's antenna by an interrogator's high-frequency carrier signal and transmits wave packets in that it excites the antenna with a voltage having a phase (?t), which is always set at the beginning of transmission of each said wave packet shifted with respect to said first phase (?i) by the same phase angle (??). At ??=180° an amplitude of voltage across an interrogator's antenna, when some of said wave packets influence this antenna, attains the largest attainable interference rise. Miniature actively transmitting smart tags are enabled to wirelessly communicate with said traditional interrogator and a communication range of pocket-sized tags is herewith increased.

Abstract: The transponder circuit comprises a double clock extractor unit (31, 32, 33), an antenna coil connected to a modulator rectifier block to supply a rectified supply voltage on the basis of a picked up radio-frequency signal, and a control logic receiving a clock signal (CLK) of the double clock extractor unit. The control logic supplies a modulation signal (MOD) to the modulator rectifier block as well as to the double clock extractor unit. A terminal (B1) of the antenna coil is connected to the double clock extractor unit, which comprises a first sensitive clock extractor, which is a comparator (32) with a sensitivity threshold defined by a low reference voltage (Vref), and a second clock extractor, which consists of two successive inverters (31, 33).

Abstract: The electronic device, in particular a transponder, includes a non volatile memory (EEPROM) having a plurality of words 1 to N whose read and/or write access can be locked. The protection register (22) is formed of two protection words A and B these two protection words are alternately active and inactive during the successive locking of words 1 to N of the programmable memory (16). The state of the protection register is defined by the active word. An initially active word is not deleted until the content thereof has been copied into the inactive word. Once the content has been altered in accordance with the lock command, the initially inactive word becomes the active word of the protection register.

Abstract: An amplitude of a carrier signal at an output of an impedance matching block is measured as a first amplitude value. A value of the signal amplitude at the output of the impedance matching block is calculated as a second amplitude value that a signal resulting from amplitude modulation with said modulation factor from said carrier signal should assume, said carrying signal having an amplitude with the first amplitude value. A setting of a transmitter is changed to decrease the carrier signal amplitude at the output of the impedance matching block. An amplitude of a new carrier signal at the output of the impedance matching block is measured as a new amplitude value. The transmitter setting keeps changing so many times until the new amplitude value is equal to or lower than said second amplitude value or within a predetermined tolerance range around said second amplitude value.

Abstract: The electronic circuit is intended to form with an antenna a responder that operates without resetting to zero when the power supply of the electronic circuit is switched on (without POR). To increase efficiency and reduce the costs of testing a plurality of such integrated circuits in a wafer, means are provided that allow the logic circuit (8) to be reset to zero during such a test by electrical contact with the pads (P1, P2) of each circuit by using two extractors (12 and 14) of clock signals (CL1 and CL2) connected to the inputs of a generator (20) of a zero reset signal (SR). The state of the generator is essentially given by the difference in pulses received from the two clock signal extractors. As soon as the state of the generator corresponds to a value equal to or greater than a predefined integer, the logic circuit is reset to zero, which never occurs with the responder receiving an interrogation signal of a reader.

Abstract: The transponder circuit comprises a double clock extractor unit (31, 32, 33), an antenna coil connected to a modulator rectifier block to supply a rectified supply voltage on the basis of a picked up radio-frequency signal, and a control logic receiving a clock signal (CLK) of the double clock extractor unit. The control logic supplies a modulation signal (MOD) to the modulator rectifier block as well as to the double clock extractor unit. A terminal (B1) of the antenna coil is connected to the double clock extractor unit, which comprises a first sensitive clock extractor, which is a comparator (32) with a sensitivity threshold defined by a low reference voltage (Vref), and a second clock extractor, which consists of two successive inverters (31, 33).

Abstract: The electronic device, in particular a transponder, includes a non volatile memory (EEPROM) having a plurality of words 1 to N whose read and/or write access can be locked. The protection register (22) is formed of two protection words A and B these two protection words are alternately active and inactive during the successive locking of words 1 to N of the programmable memory (16). The state of the protection register is defined by the active word. An initially active word is not deleted until the content thereof has been copied into the inactive word. Once the content has been altered in accordance with the lock command, the initially inactive word becomes the active word of the protection register.

Abstract: The invention concerns a method for identifying a plurality of passive transponders 6 using a reader comprising several antennae whose detection fields do not merge spatially and/or temporally, said transponders comprising an analogue 34 or digital 52 memory for storing binary information for a certain time interval in the absence of any reader feeding fields. For each antenna, the method sequentially implements an anti-collision protocol during which each identified transponder is set in a “silent” mode. The method provides for this information to be stored in said memory of each transponder for a time interval including at least the switching period between a first antenna and a second antenna of the reader. This prevents detection of the same transponders by several antennae, which makes the identification method quicker and more efficient.

Abstract: A communication system comprising a base station (20) and a plurality of transponders (TR; 21 to 26), the base station (20) emitting an electromagnetic field (1) defining a communication volume (2) in which several transponders (21, 22, 23) are susceptible to be situated. The transponders are adapted to generate identification messages (30) in response to the electromagnetic field (1). The base station (20) is adapted to selectively communicate with each transponder by generating communication initiation signals (40) in response to the identification messages (30). Each transponder is adapted to open a communication window (60) in response to a communication initiation signal (40) during which information may be exchanged and/or commands may be sent.