Abstract: A method for wireless data transmission, for example for RFID systems, between a base station and a transponder is provided. For wireless data transmission between a base station and a transponder, data are wirelessly and bidirectionally transmitted between the base station and the transponder through a first interface of a first interface type using a first data transmission protocol, and data are wirelessly and bidirectionally transmitted between the base station and the transponder through at least one second interface of a second interface type using a second data transmission protocol. The first data transmission protocol and the second data transmission protocol correspond at least in part.

Abstract: The invention concerns a modulator (M) for data transmission between a transponder and a base station, which amplitude modulates and/or phase modulates a received electromagnetic carrier signal as a function of data to be transmitted, having a control input at which a modulation control signal is present, having a rectifier (GL) circuit for rectifying the received electromagnetic carrier signal which has at least one rectifier stage (S1-S3), having at least one switching device (SE) which is controllable through the modulation control signal and whose output side intervenes in at least one rectifier stage of the rectifier circuit, and by means of which a reference voltage can be applied to at least one node (H1-H3) of said rectifier stage. The invention further concerns a transponder with such a modulator and a modulation method for operating such [a modulator].

Abstract: A method for data communication between a base station and at least one transponder by a high-frequency electromagnetic carrier signal is disclosed, onto which information packets are modulated, whereby each information packet has a header section, a middle section, and an end section and whereby the middle section has a data field for the transmission of data and/or address information and a protection field placed thereafter for the correction of errors in the transmission of the data and/or address information, whereby after the data field the base station inserts at least one control field, by which the protection field following the inserted control field can be changed in such a way that the duration of an information packet is set variably. The invention relates further to a base station for carrying out this method, to a data communication system containing a base station and at least one transponder in communicative wireless contact with the base station.

Abstract: A method for selecting at least one transponder or a sensor in RFID or remote-sensor systems provided with a plurality of transponders or sensors (tags), in particular in systems provided with a plurality of reading devices, is disclosed. The inventive method includes the feature that in pre-selecting individual transponders or sensors by at least one reading device and, after the successful selection of at least one transponder or sensor, data, in particular for conforming the preselection, is asynchronously transmitted during at least one protocol section from the transponder or sensor to the reading device. The invention makes it possible to efficiently reduce the potentially disturbing control signals of the reading device(s), thereby improving the transmission characteristics of said systems.

Abstract: A method is disclosed 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, each information packet comprising a header section, a middle section, and a terminating end section. This end section s provided with at least two EOF symbols which together indicate the end of an information packet. An additional information field is provided which is inserted into the end section between two EOF symbols and contains additional information. The invention relates further to a base station and a data communication system.

Abstract: A method for recognizing time-variable functional states, e.g., in the course of a pro-gramming process, in RFID systems is disclosed, which includes at least one transponder or remote sensor and at least one base station, which transmits data and/or power to the transponder or sensor by a carrier signal. According to the invention, after a specified process state is attained at least one confirmation symbol is transmitted by the transponder or sensor to the base station. As a result, no unfavorable “worst case” scenario has to be provided for chronologically controlling time-variable processes because the base station is able to clearly recognize the beginning and end of the process, as well as the state thereof. RFID systems or remote sensor systems can thus be controlled more quickly and more reliably, resulting especially in reduced costs.

Abstract: A circuit arrangement for phase modulation in an input circuit of a backscattering transponder includes a varactor and at most one capacitor connected in series between two antenna terminals, as well as a varactor control arrangement applying a control voltage to the varactor to selectively vary the capacitance thereof. One of the antenna terminals is connected directly to one of the varactor terminals without a capacitor therebetween. The other antenna terminal is connected either directly or through a capacitor to the other varactor terminal. One antenna terminal and/or one varactor terminal can be grounded. A DC-decoupling capacitor can be connected between a transponder circuit unit or a circuit ground and the common junction of the antenna terminal with the varactor terminal. The circuit arrangement is simple, economical, and uses minimal chip area by omitting further capacitors between the antenna terminals.

Abstract: A method for transponder access control is disclosed, in which a first identification is stored in the transponder, which is transmitted to a reader unit upon appropriate request by the unit. At least one second identification and an identification selection criterion are stored in the transponder, during a request by the reader unit depending on the identification selection criterion either the first identification or the at least second identification is transmitted and, when the second identification is transmitted, access to the transponder, particularly to the first identification, is released by the transponder when the reader unit transmits a password assigned to the second identification to the transponder.

Abstract: A circuit arrangement for phase modulation in an input circuit of a backscattering transponder includes a varactor and at least one capacitor connected in series between two antenna terminals, and at least two voltage sources selectively connected through at least two switches to at least one terminal of the varactor. A control unit selectively opens and closes the switches in response to the data to be phase-modulated onto the backscattered signal. By selectively connecting the different voltage values of the respective voltage sources to the varactor terminal(s) through the switches, the capacitance of the varactor and correspondingly the input impedance of the input circuit are thereby varied, so as to provide respective different phase positions of the phase modulation.

Abstract: For transmitting data, a receiving/backscattering arrangement receives, modulates and reflects or backscatters electromagnetic waves emitted by a base station. The modulation corresponds to the data to be transmitted and is carried out selectively using first and/or second different modulation methods depending on the received field strength of the received electromagnetic waves. Preferably, phase shift keying is used especially or at least at low field strengths at far range, while amplitude shift keying is used additionally or alternatively for high field strengths at close range. The two modulation methods can be superimposed. A circuit arrangement includes two different modulator arrangements to perform the two modulation methods depending on the received field strength. The second modulator arrangement preferably comprises a multi-stage voltage multiplier circuit with a modulated switching device intervening in one of the stages to achieve the modulation.

Abstract: A selection method for selecting at least one transponder located in the response area of a base station, which are linked to one another by a wireless bidirectional data communication path, in which method the base station transmits an electromagnetic carrier signal, which has at least one arbitration symbol, wherein each arbitration symbol has a query segment in which data are encoded by the base station, and has a response segment that can be used by the transponder for coding and modulation of information for return data transmission, wherein the selection of a transponder takes place on the basis of distinguishable points in time in the time segment for the modulation that are produced from a reference time which is derived from the arbitration symbol itself.

Abstract: In a method of selecting one or more transponders, the time duration of a reference interval is transmitted by the base station to the transponders in the header section of an information packet, each transponder compares the respective time durations of the reference interval and of a first time interval, and the further selection of the transponder depends on the result of the comparison.

Abstract: A method for transmitting data between a base station and at least one remote unit is provided. Conventional approaches to communication based on a predefined uniform transmission protocol do not function especially in open RFID systems with at least one base station and tags of a different (and variable) type and number, in which different customers are provided with one and the same tag solution. Primarily if several customers each wish to use a customer-specific solution, this can no longer be represented by a single uniform code. The method of the present invention makes it possible to introduce new, protocol-extending instruction sequences (protocol extensions) and to recognize these reliably as such, whereby these are not in conflict with the existing protocol.

Abstract: A method and apparatus for wireless data transmission is provided between a base station and a backscatter-based transponder, in which the transponder generates a presence signal after initialization or at predetermined time intervals, independent of data transmitted by the base station. The presence signal is generated by phase modulation and backscattering of a carrier signal transmitted by the base station.

Abstract: A method and apparatus for locating a transponder is provided. A carrier signal is transmitted by a base station and a transponder transmits a locating signal that is generated through phase modulation and backscattering of the carrier signal sent by the base station when the transponder is within a transmission range of the base station, whereby the transponder is located on the basis of the locating signal.

Abstract: An integrated circuit is combined with a transponder to function either as a voltage or power supply for the transponder by extracting energy out of an electromagnetic field transmitted by a base station or as a detector in the transponder to act as a remote sensor. For this purpose the integrated circuit comprises diode rectifiers. Each of the diode rectifiers has a first and a second service terminal and a reference terminal. In order to reduce a parasitic impedance between the first service terminal and the reference terminal, the first service terminal of at least one rectifier diode is electrically connected to a reference potential such as ground. Parasitic diode characteristics are further reduced by surrounding the respective diode or diodes by an electrical conductor path also connected to the reference potential.

Abstract: A method and device for selecting one or more transponders, in particular backscatter-based transponders, from a plurality of transponders by a base station, which method is based on a slotted ALOHA method, in which the base station defines numbered time slots and a random number generated in a given transponder determines a time slot when the transponder transmits its transponder-specific identification to the base station.

Abstract: A semiconductor structure, for improving rectifier efficiency in passive backscatter transponders or backscatter remote sensors for use in high-frequency electromagnetic fields, is provided. The semiconductor structure has a dielectric layer on whose upper side is arranged a first electrically conductive layer, and a second electrically conductive layer that is spaced apart from the first electrically conductive layer and is arranged essentially below the first electrically conductive layer and is at least partially embedded in the dielectric layer. The dielectric layer has its lower side arranged on a semiconductor substrate of a first conductivity type within which is formed a more highly doped first zone of the first conductivity type which surrounds an even more highly doped second zone of the first conductivity type connected to a reference voltage. Whereby, the first zone can be arranged essentially completely under the first and second electrically conductive layers.

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.