In a communication arrangement (1) provided for transmitting data (DA)
to a transponder (2) which arrangement includes a data source (5)
for delivering data (DA) and includes a carrier signal generator (6) for
generating a carrier signal (CS) and includes modulation means (7) to which
can be applied the data (DA) and the carrier signal (CS) and which modulation means
are provided for modulating a carrier signal (CS) in accordance with the data (DA)
and for delivering a modulated carrier signal (CSM) to transmitting means (8)
having an input resistance (9), the modulation means (7) have a changeable
output resistance (10) which forms a resistance network together with the
input resistance (9) of the transmitting means (8), and resistance
change means (25) for changing the output resistance (10) in accordance
with the data (DA).