Abstract: A method for communicating between a control unit and a plurality of remote units located in the response area of the control unit is provided. The remote units are prompted to transmit a data sequence to the control unit upon receipt of a command sent by the control unit. The control unit transmits a control signal to the remote units substantially simultaneously with the transmission of the data sequence as a function of a communication state, such as the absence of a transmission of the data sequence by at least one remote unit or an at least partially simultaneous transmission of the data sequence by more than one remote unit. In this way, communication methods can be shortened, in particular in terms of time, without adversely affecting communication reliability.

Abstract: A method for wireless data transmission between a base station and a transponder is provided, in which data are transmitted between the base station and the transponder in the form of data packets that include a header section with at least one symbol for setting one or more transmission parameters and include at least one additional section. The transponder monitors, during the data transmission, to determine whether a time period between two successive symbol delimiters transmitted by the base station exceeds a maximum time, and if the maximum value is exceeded, a receiver unit of the transponder is reset. The maximum time can be determined in the transponder on the basis of the at least one symbol in the header section.

Abstract: A method for wireless data communication between a base station and at least one transponder by a high-frequency electromagnetic carrier signal, onto which information packets are modulated, wherein each information packet has a header section, a middle section, and a terminating end section, wherein the middle section has a data field, which contains the data necessary for the data communication, wherein at least one additional control field is inserted into the data field by which the structure of the information packets can be variably adjusted within the region of the data field. The invention relates further to a transponder, a base station, and a data communication system.

Abstract: A method and system for data communication between a base station and at least one transponder via a high-frequency electromagnetic carrier signal onto which information packets are modulated. Each information packet has a header section, a middle section, and a trailer section. The header section can be provided in a forward link of a data communication between the base station and the transponders for controlling data communication. The header section is used in a return link of a data communication in order to transmit information from the transponder to the base station.

Abstract: A method and apparatus for wireless data transmission between a base station and one or more, in particular, passive and/or backscatter-based transponders, in which the base station modulates a carrier signal with a modulation signal, to generate synchronization markers, and transmits the modulated carrier signal. Whereby, a frequency of the modulated carrier signal can be switched between different frequency values.

Abstract: A security device for a transponder with a kill and/or cloak function is provided. The security device includes a memory device, in which a first, open password is stored, an input, into which a second, secret password is coupled, a cryptologic device, which is connected to the input and generates a checksum from the second password, and a comparison unit, which compares the checksum and the first password and which upon an agreement generates a kill and/or cloak control instruction to activate and/or deactivate a kill and/or cloak mechanism, which can be tapped at an output. A method for configuring a security device and a method for operating a transponder, and a transponder having the security device are also provided.

Abstract: A method and system is provided for selecting one or more transponders from a plurality of transponders by a base station, in which a random number generated in a given transponder determines a point in time when the transponder in question transmits an identification to the base station. The base station transmits a selection command, then, in order to determine whether at least one transponder is addressed by the selection command, all addressed transponders substantially simultaneously transmit an identification to the base station at a first point in time, and if more than one transponder is addressed, each addressed transponder transmits its identification to the base station at least once more at an additional point in time. The additional point in time being determined by the value of the random number generated or to be generated in the relevant transponder.

Abstract: A tuned antenna resonant circuit substantially increases the range of a passive transponder in a high-frequency electromagnetic carrier field, in that the real and imaginary parts of the impedance associated with the contact surface of the antenna contact are minimized and the energy absorbed from the carrier field by a serial resonant circuit is used to the greatest possible extent for generating the supply voltage for the integrated circuit of the transponder.

Abstract: An integrated circuit includes a cuttable circuit structure, which in a cut state prevents access to at least one circuit element of the integrated circuit. Whereby, the circuit structure is positioned so that it is cut during dicing of the integrated circuit from a wafer.

Abstract: A method and apparatus is provided for data transmission in RFID and remote sensor systems with at least one reader and a plurality of transponders or remote sensors being located in an electromagnetic field of the reader, in which a multipart return link header containing transmission parameters for the return link, such as timing or modulation references, is transmitted at the beginning of a return link transmission of useful data from a transponder or sensor to a reader. A relative time duration of individual subsymbols of the return link header is modified to select a data transfer mode from among a number of different data transfer modes. A combination of different return link transmission mechanisms is thereby possible, whereby these are mutually compatible and moreover are simple to realize in terms of circuitry and control engineering.

Abstract: A method and apparatus includes at least one transponder or sensor to transmit useful data in an asynchronous mode to at least one reader. Before the start of the useful data transmission, the reader transmits a return link header to the transponder or sensor, which contains at least one bit length reference symbol as a reference time to define the bit length in the return link.

Abstract: A method for wireless data transmission between a base station and one or more, in particular passive, transponders is provided, in which electromagnetic carrier waves are emitted by the base station. Data comprising successive characters are transmitted from a respective transponder to the base station by modulation and backscattering of the electromagnetic carrier waves, and a respective one of the characters is coded and transmitted by a respective transponder within a predefined time interval. Within at least one of the predefined time intervals, a safeguard character formed from the data to be transmitted is transmitted in addition to the character to be transmitted.

Abstract: A method and apparatus for transmitting data in a radio frequency identification system, which includes a reader and at least one transponder, is provided. The reader transmits data sequences to the transponder including at least command data, associated check data, and a subsequent return link header data. Upon receiving unrecognized command data and/or unsupported parameter and address data the transponder notifies the reader of this condition. The notification takes place at times when the reader transmits end signals indicating an end of a data sequence, transmits an optional parameter and address data, or transmits the return link header data. Thus, communication between the reader and other transponders is not disrupted when a transponder cannot execute a command.

Abstract: A method and device for wireless data transmission between a base station and one or more transponders, in which electromagnetic carrier waves are emitted by the base station and symbols are transmitted from a given transponder to the base station by modulation and backscattering of the electromagnetic carrier waves, wherein a change in a modulation state takes place synchronously with synchronization markers transmitted by the base station. A change in the modulation state is carried out by a transponder with a specifiable time delay that is relative to the synchronization markers.

Abstract: A circuit arrangement for deriving electrical power from a received electromagnetic field to power a transponder includes a detuning unit connected between two antenna terminals for limiting the power absorbed by the antenna. The detuning unit includes a component having an impedance that passively varies or is actively varied dependent on the field strength of the field prevailing at the antenna. One arrangement of the detuning unit includes two varactor diodes connected anti-parallel between the antenna terminals. Another arrangement of the detuning unit includes a varactor arranged in series between two capacitors between the antenna terminals, a field strength detector, and a controllable voltage source connected to apply to the varactor a control voltage that varies depending on the detected field strength. Thereby, the input impedance varies depending on the field strength, to achieve impedance matching for a low field strength, and a mis-matched condition for a high field strength.

Abstract: In known methods for the transmission of data the effective data transmission rate is reduced through errors in the data transmission, because the entire data word must respectively be transmitted again in the event of errors. With the new method, an error correction during the transmission of the data word is made possible through the change of the modulation state at pre-defined time points. Thereby the effective data transmission rate is increased.

Abstract: A method and circuit for wireless data transmission between a base station and one or more transponders is provided in which the base station modulates a carrier signal with a modulation signal and transmits it, in which symbols that are to be transmitted are coded by the base station using sequential delimiters. A value of a particular symbol being determined by the time period between two sequential delimiters, and in which the particular delimiter is generated by changing the modulation signal during a modulation period. Whereby, the modulation signal is preferably a noise signal during the modulation period.

Abstract: Known methods for the selection of transponders require a large time duration, because in this context the data transmitted according to the half-duplex principle. With the new method, the transponders can be identified with a small time expenditure through the transmission of the time duration of a reference interval, because the data are transmitted in the full-duplex principle.

Abstract: A transponder receives its operating energy from an external source such as a radio signal or a battery. Such transponders are used for example in a vehicle or in a remote sensor. The response range of the transponder is increased by converting the received energy into an operating voltage which in turn is used to generate a function voltage required for performing a current function sequence. The generated function voltage is checked to determine at least one characteristic of the generated function voltage. The determined function voltage characteristic, for example a voltage value directly representing the function voltage, is then used to acknowledge or reject a result of performing the function sequence. Thus, the time duration for performing any current function sequence is flexibly adapted to the current requirements of that function sequence, whereby the power consumption of the transponder is optimally reduced and the response range respectively increased.

Abstract: In known methods for the transmission of data, the data transmission rate is reduced by bit errors especially at high carrier frequencies. In the new method, the data transmission rate can be significantly increased due to the increased reliability in the data transmission by means of the integration of a test signal.