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: A transponder is provided with a clock supply unit that includes a ring oscillator and can be used in RFID systems.

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: 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: An RF transponder includes an input circuit, a read/memory circuit, and a circuit arrangement for holding a control state. The circuit arrangement includes a first storage device (e.g. a D-flip-flop) for storing the control state dependent on received control signals, and a second storage device (e.g. a capacitor and a transistor) for holding the control state during a period of inadequate energy supply to the circuit arrangement, e.g. while the transponder is in a field gap of the electromagnetic field emitted by a base station with which the transponder communicates. In an operating method, the control state is held by the second storage device during a period of inadequate energy supply. Then, when adequate energy is again supplied, the transponder resumes the control state that was held by the second storage device. The transponder continues to operate properly according to an anti-collision procedure in a system of several transponders communicating individually with a base station.

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: A receiving/backscattering arrangement for carrying out a contactless data transmission includes an integrated circuit having two antenna contacts, a series arrangement of three high quality capacitances connected between the two antenna contacts, whereby the middle capacitance is an MOS varactor, a controllable variable voltage source connected across the MOS varactor, and a control unit that controls the voltage source. The receiving/backscattering arrangement is especially a passive transponder with a rectifier connected between the antenna contacts, or a semi-passive transponder including a battery or solar cell, to provide the required supply voltage for the circuit. The arrangement achieves a large communication range, for receiving and modulating an interrogation signal, and backscattering the modulated response signal with a high efficiency and low losses. The integrated circuit structure is compact and economical.