Abstract:
A transponder communication device has an interrogation signal generator for generating an interrogation signal, a transmitter for transmitting the interrogation signal to a number of transponders, and a receiver for receiving answers signal from transponders. A transponder has an interrogation signal detector, an answer signal generator, and a state setting controller for setting a state of the transponder. The transponder communication device selects a single transponder from the number of transponders. First, the transponder communication device transmits an initial interrogation signal is transmitted to all transponders when the transponders are in an active state. In dependence of answer signals received from the transponders, the transponder communication device transmits a standby setting signal to at least one transponder at a time to instruct the transponders to adopt a standby state. In the standby state the transponders wait until a single other transponders has been selected. Thereafter all unselected transponders are selected by first setting the unselected transponders into an active state, from the standby state. Selected transponders are set into a passive state until all transponders have been selected. Thereupon, the active state is restored for all transponders.
Abstract:
A data carrier (1) for the transmission of transmission data (UD) to a base station over a transmission time range (TT) containing load time ranges (TA) and load relief time ranges (TB0, TB1) comprises cut-off means (13) which, once activated, set principal power consumers (10, 12) of the data carrier (1) into an energy-saving operating condition for a cut-off time range containing the load time range (TA), so that the storage capacitor (9) for operation of the passive data carrier (1) over the load time ranges (TA) may advantageously have only a relatively low capacitance.
Abstract:
A data carrier (1) comprises an integrated circuit (3), which integrated circuit (3) comprises a tolerance-defined main capacitor (35) which is connected to a coil (4) of the data carrier (1), and which integrated circuit (3) comprises at least one integrated additional capacitor (32) which is optionally connectable to the coil (4) of the data carrier (1) so that a parallel switching configuration of the main capacitor (35) with the at least one additional capacitor (32) is achievable. The optional parallel arrangement of the at least one additional capacitor (32) leads to a reduction of the tolerance range of the nominal capacitance of the main capacitor (35) when the effectively realized capacitance of the main capacitor (35) is reduced by a factor F and the at least one additional capacitor (32) has a fraction K of the nominal capacitance of the main capacitor (35).