Abstract: An active transponder for synthetic aperture radar systems includes a receiving antenna for receiving a first radiofrequency signal modulated according to a first train of one or more first pulses, separating means comprising two outputs outputting the first radiofrequency signal, second processing means connected to a first output of the separating means to generate a code synchronized with the first pulses, signal generating means connected to the second output and to the second processing means generate a second radiofrequency signal modulated by the code, and a transmitting antenna means to transmit the second radiofrequency signal to generate, for each one of the first pulses, a sequence of one or more second pulses, the code being synchronized with the second pulses.

Abstract: The invention concerns an active transponder, particularly for synthetic aperture radar systems, or SAR, comprising: a receiving antenna (20) for receiving a first radiofrequency signal modulated according to a first train of one or more first pulses; separating means (3), comprising two outputs at each one of which it outputs the first radiofrequency signal; second processing means (7, 8, 9, 10, 11, 12), connected to a first output of the separating means (3), capable to generate at least one code synchronised with the first pulses; signal generating means (4), connected to a second output of the separating means (3) and to the second processing means (7, 8, 9, 10, 11, 12), capable to generate a second radiofrequency signal modulated by said at least one code generated by the second processing means (7, 8, 9, 10, 11, 12); and a transmitting antenna means (30), capable to transmit the second radiofrequency signal; characterised in that the second processing means (7, 8, 9, 10, 11, 12) is capable to generate,