The interrogation device is used for identifying a target device. A transmitter
is designed for transmitting a coded electromagnetic radiation. The target device
has sensor means for detecting this radiation and for converting it into electrical
signals, which are supplied to an evaluation unit, as well as transmitting means
which, in accordance with decisions made by the evaluation unit, return messages
to receiving means located inside or outside of the transmitter. The transmitter
comprises a circuit with an oscillator and an antenna, which are designed to generate
individual pulses, or short bursts of pulses in the giga-frequency range, which
are chronologically modulated. A coded information signal is obtained from these pulses.
