Abstract: The invention concerns an electric circuit and a method for pulse modulation of a carrier signal (10). The circuit comprises a pulse generator for generating a current pulse and at least one diode switch (12) which can be controlled by the current pulse. To modulate the carrier signal (10) with a particularly short pulse with a clear, square envelope (21), using as simple and inexpensive a circuit as possible, the invention proposes that the circuit comprises at least one chargeable capacitive element (C) whose discharge current controls the at least one diode switch (12). The capacitive element (C) is formed e.g. as a capacitor. The capacitive element (C) is charged with a charging voltage (UL) via a charging resistance (R). Switching of a transistor (18) initiates the discharging process and a current pulse is generated for controlling the diode switch (12).