Transponder unit

摘要

A transponder unit for transferring data to a reading device by modulation of an electromagnetic field includes a device for varying the data block size of the data by restricting the same or by modifying a clock signal, in dependence on a frequency difference between a clock frequency of a clock signal transferred from the reading device to the transponder unit, and a frequency generator frequency of a frequency generator of the transponder unit.

主权项

1. A transponder for transferring data to a reading device using an electromagnetic field, comprising:
a receiver arranged to receive a clock signal emitted by the reading device at a clock frequency; a frequency generator configured to generate a frequency generator frequency which is employed for clocking transfer of the data; a frequency comparator which is configured to determine a frequency difference between the clock frequency and the frequency generator frequency; and a device arranged to restrict the data block size of the data to a data block size dependent on the frequency difference, wherein the device restricting the data block size of the data is configured to restrict the data block size to the following data block size ByteMaxBlock dependent on the frequency difference:
ByteMaxBlock≦[ΔPulsemax·fc]/[||·BitByte·PulseBit],  (1)where ByteMaxBlock is the data block size in bytes per data block, fc is the frequency generator frequency, is the frequency difference between the clock frequency and the frequency generator frequency, BitByte is the number of bits per byte, PulseBit is the number of pulses of the frequency generator signal per bit, and ΔPulsemax is a constant which is smaller than PulseBit/2 or PulseBit/4 or smaller than or equal to PulseBit/8.