Abstract: A proximity detonator which derives its firing criterion from reflected beam measurements and thus obtains information about the radial relative velocity of the detonator with respect to its target object by evaluating the Doppler effect, wherein the firing signal is produced by a circuit including a function generator whose output voltage has a time sequence which corresponds to the decrease in radial relative velocity as the detonator approaches its target object (possibly under consideration of a correction value resulting from the firing law), a voltage controlled oscillator whose control input is connected to the output of the function generator, and a phase comparator having two signal inputs, one of which receives a Doppler signal which corresponds to the radial relative velocity and the other of which is connected to the output of the oscillator.