A circuitry for generating a narrow impulse including an input device coupled to a matching circuitry that is coupled to a step recovery diode (SRD). The input device is configured to receive a succession of digital input signals, each characterized by having high level and low level portions. The signals having less than 50% duty cycle. The input device is configured to drive forward the SRD through the matching circuitry during the high level portion of the digital signal, whereby the SRD stores sufficient power for generating the narrow impulse following the falling edge of the high level portion of the digital input signal.